JAVA文件上传总结

约定不等于承诺〃 2022-08-25 14:48 154阅读 0赞

文件上传有很多组件，我们只要学会下面几种就OK了：

1 APACHE  FILEUPLOAD：

将Apache的commons-fileupload.jar放在应用程序的WEB-INF\\lib下，即可使用。下面举例介绍如何使用它的文件上传功能。

所使用的fileUpload版本为1.2，环境为Eclipse3.3+MyEclipse6.0。FileUpload 是基于 Commons IO的，所以在进入项目前先确定Commons IO的jar包（本文使用[commons-io-1.3.2.jar][]）在WEB-INF\\lib下。

此文作示例工程可在文章最后的附件中下载。

**示例1**

最简单的例子，通过ServletFileUpload静态类来解析Request，工厂类FileItemFactory会对mulipart类的表单中的所有字段进行处理，不只是file字段。getName（）得到文件名，getString（）得到表单数据内容，isFormField（）可判断是否为普通的表单项。

demo1.html

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color:#ff660">//</span><span style="color:#ff660">必须是</span><span style="color:#ff660">multipart</span><span style="color:#ff660">的表单数据。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">form </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myform" </span><span style="color:#7f07f">action</span><span style="color:black">=</span><span style="color:#2a0ff">"demo1.jsp" </span><span style="color:#7f07f">method</span><span style="color:black">=</span><span style="color:#2a0ff">"post"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">enctype</span><span style="color:black">=</span><span style="color:#2a0ff">"multipart/form-data"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> Your name: <span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"text" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"name" </span><span style="color:#7f07f">size</span><span style="color:black">=</span><span style="color:#2a0ff">"15"</span><span style="color:teal">&gt;&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File:<span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"file" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myfile"</span><span style="color:teal">&gt;&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">value</span><span style="color:black">=</span><span style="color:#2a0ff">"Commit"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;/</span><span style="color:#3f7f7f">form</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

demo1.jsp

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">language</span><span style="color:black">=</span><span style="color:#2a0ff">"java" </span><span style="color:#7f07f">contentType</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">pageEncoding</span><span style="color:black">=</span><span style="color:#2a0ff">"GB18030"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.servlet.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.disk.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"java.util.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;!</span><span style="color:#3f7f7f">DOCTYPE </span><span style="color:navy">HTML </span><span style="color:gray">PUBLIC </span> <span style="color:navy">"-//W3C//DTD HTML 4.01 Transitional//EN"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">boolean</span></strong><span style="color:black"> isMultipart = ServletFileUpload.isMultipartContent(request);</span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">检查输入请求是否为</span><span style="color:#3f7f5f">multipart</span><span style="color:#3f7f5f">表单数据。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">if</span></strong><span style="color:black"> (isMultipart == </span><strong><span style="color:#7f055">true</span></strong><span style="color:black">) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> FileItemFactory factory = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> DiskFileItemFactory();</span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">为该请求创建一个</span><span style="color:#3f7f5f">DiskFileItemFactory</span><span style="color:#3f7f5f">对象</span><span style="color:#3f7f5f">，</span><span style="color:#3f7f5f">通过它来解析请求。执行解析后，所有的表单项目都保存在一个</span><span style="color:#3f7f5f">List</span><span style="color:#3f7f5f">中。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> ServletFileUpload upload = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> ServletFileUpload(factory);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> List&lt;FileItem&gt; items = upload.parseRequest(request);</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> Iterator&lt;FileItem&gt; itr = items.iterator();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">while</span></strong><span style="color:black"> (itr.hasNext()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>FileItem item = (FileItem) itr.next();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">检查当前项目是普通表单项目还是上传文件。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><strong><span style="color:#7f055">if</span></strong><span style="color:black"> (item.isFormField()) { </span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">如果是普通表单项目，显示表单内容。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> String fieldName = item.getFieldName();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">if</span></strong><span style="color:black"> (fieldName.equals(</span><span style="color:#2a0ff">"name"</span><span style="color:black">)) </span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">对应</span><span style="color:#3f7f5f">demo1.html</span><span style="color:#3f7f5f">中</span><span style="color:#3f7f5f">type="text" name="name"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>out.print(<span style="color:#2a0ff">"the field name is"</span><span style="color:black"> + item.getString());</span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">显示表单内容。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> out.print(<span style="color:#2a0ff">"&lt;br&gt;"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>} <strong><span style="color:#7f055">else</span></strong><span style="color:black"> { </span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">如果是上传文件，显示文件名。</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> out.print(<span style="color:#2a0ff">"the upload file name is"</span><span style="color:black"> + item.getName());</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> out.print(<span style="color:#2a0ff">"&lt;br&gt;"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>}</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> } <strong><span style="color:#7f055">else</span></strong><span style="color:black"> { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> out.print(<span style="color:#2a0ff">"the enctype must be multipart/form-data"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

结果：

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px">the field name isjeff<br> the upload file name isD:\C语言考试样题\作业题.rar</span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

**示例2**

上传两个文件到指定的目录。

demo2.html

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">form </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myform" </span><span style="color:#7f07f">action</span><span style="color:black">=</span><span style="color:#2a0ff">"demo2.jsp" </span><span style="color:#7f07f">method</span><span style="color:black">=</span><span style="color:#2a0ff">"post"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">enctype</span><span style="color:black">=</span><span style="color:#2a0ff">"multipart/form-data"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File1:<span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"file" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myfile"</span><span style="color:teal">&gt;&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File2:<span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"file" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myfile"</span><span style="color:teal">&gt;&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">value</span><span style="color:black">=</span><span style="color:#2a0ff">"Commit"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;/</span><span style="color:#3f7f7f">form</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

demo2.jsp

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">language</span><span style="color:black">=</span><span style="color:#2a0ff">"java" </span><span style="color:#7f07f">contentType</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">pageEncoding</span><span style="color:black">=</span><span style="color:#2a0ff">"GB18030"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.servlet.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.disk.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"java.util.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"java.io.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;!</span><span style="color:#3f7f7f">DOCTYPE </span><span style="color:navy">HTML </span><span style="color:gray">PUBLIC </span> <span style="color:navy">"-//W3C//DTD HTML 4.01 Transitional//EN"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%</span><span style="color:black">String uploadPath=</span><span style="color:#2a0ff">"D:\\temp"</span><span style="color:black">;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp; </span> <strong><span style="color:#7f055">boolean</span></strong><span style="color:black"> isMultipart = ServletFileUpload.isMultipartContent(request);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp; </span> <strong><span style="color:#7f055">if</span></strong><span style="color:black">(isMultipart==</span><strong><span style="color:#7f055">true</span></strong><span style="color:black">){ </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp; <strong><span style="color:#7f055">try</span></strong><span style="color:black">{ </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; FileItemFactory factory = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> DiskFileItemFactory();</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; ServletFileUpload upload = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> ServletFileUpload(factory);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; List&lt;FileItem&gt; items = upload.parseRequest(request);<span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">得到所有的文件</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp; Iterator&lt;FileItem&gt; itr = items.iterator();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; <strong><span style="color:#7f055">while</span></strong><span style="color:black">(itr.hasNext()){ </span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">依次处理每个文件</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> &nbsp; FileItem item=(FileItem)itr.next();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> &nbsp; String fileName=item.getName();<span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">获得文件名，包括路径</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> &nbsp; <strong><span style="color:#7f055">if</span></strong><span style="color:black">(fileName!=</span><strong><span style="color:#7f055">null</span></strong><span style="color:black">){ </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>&nbsp; File fullFile=<strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(item.getName());</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>&nbsp; File savedFile=<strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(uploadPath,fullFile.getName());</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>&nbsp; item.write(savedFile);</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> &nbsp; }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; out.print(<span style="color:#2a0ff">"upload succeed"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp; }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp; <strong><span style="color:#7f055">catch</span></strong><span style="color:black">(Exception e){ </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> &nbsp; e.printStackTrace();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp; }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp; </span> <strong><span style="color:#7f055">else</span></strong><span style="color:black">{ </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp; out.println(<span style="color:#2a0ff">"the enctype must be multipart/form-data"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

结果：

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px">upload succeed</span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

此时，在"D:\\temp"下可以看到你上传的两个文件。

**示例3**

上传一个文件到指定的目录，并限定文件大小。

demo3.html

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">form </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myform" </span><span style="color:#7f07f">action</span><span style="color:black">=</span><span style="color:#2a0ff">"demo3.jsp" </span><span style="color:#7f07f">method</span><span style="color:black">=</span><span style="color:#2a0ff">"post"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">enctype</span><span style="color:black">=</span><span style="color:#2a0ff">"multipart/form-data"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File:<span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"file" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myfile"</span><span style="color:teal">&gt;&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">value</span><span style="color:black">=</span><span style="color:#2a0ff">"Commit"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;/</span><span style="color:#3f7f7f">form</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

demo3.jsp

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">language</span><span style="color:black">=</span><span style="color:#2a0ff">"java" </span><span style="color:#7f07f">contentType</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">pageEncoding</span><span style="color:black">=</span><span style="color:#2a0ff">"GB18030"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.servlet.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"org.apache.commons.fileupload.disk.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"java.util.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%@ </span> <span style="color:#3f7f7f">page </span><span style="color:#7f07f">import</span><span style="color:black">=</span><span style="color:#2a0ff">"java.io.*"</span><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;!</span><span style="color:#3f7f7f">DOCTYPE </span><span style="color:navy">HTML </span><span style="color:gray">PUBLIC </span> <span style="color:navy">"-//W3C//DTD HTML 4.01 Transitional//EN"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">&lt;%</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> File uploadPath = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(</span><span style="color:#2a0ff">"D:\\temp"</span><span style="color:black">);</span><span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">上传文件目录</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">if</span></strong><span style="color:black"> (!uploadPath.exists()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> uploadPath.mkdirs();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">临时文件目录</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> File tempPathFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(</span><span style="color:#2a0ff">"d:\\temp\\buffer\\"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">if</span></strong><span style="color:black"> (!tempPathFile.exists()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> tempPathFile.mkdirs();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">try</span></strong><span style="color:black"> { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#3f7f5f">// Create a factory for disk-based file items</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> DiskFileItemFactory factory = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> DiskFileItemFactory();</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#3f7f5f">// Set factory constraints</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> factory.setSizeThreshold(4096); <span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">设置缓冲区大小，这里是</span><span style="color:#3f7f5f">4kb</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> factory.setRepository(tempPathFile);<span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">设置缓冲区目录</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#3f7f5f">// Create a new file upload handler</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> ServletFileUpload upload = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> ServletFileUpload(factory);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#3f7f5f">// Set overall request size constraint</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> upload.setSizeMax(4194304); <span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">设置最大文件尺寸，这里是</span><span style="color:#3f7f5f">4MB</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> List&lt;FileItem&gt; items = upload.parseRequest(request);<span style="color:#3f7f5f">//</span><span style="color:#3f7f5f">得到所有的文件</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> Iterator&lt;FileItem&gt; i = items.iterator();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">while</span></strong><span style="color:black"> (i.hasNext()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>FileItem fi = (FileItem) i.next();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>String fileName = fi.getName();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><strong><span style="color:#7f055">if</span></strong><span style="color:black"> (fileName != </span><strong><span style="color:#7f055">null</span></strong><span style="color:black">) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File fullFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(fi.getName());</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File savedFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(uploadPath, fullFile</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>.getName());</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> fi.write(savedFile);</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>}</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> out.print(<span style="color:#2a0ff">"upload succeed"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> } <strong><span style="color:#7f055">catch</span></strong><span style="color:black"> (Exception e) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> e.printStackTrace();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#bf5f3f">%&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

**示例4**

利用Servlet来实现文件上传。

Upload.java

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">package</span></strong><span style="color:black"> com.zj.sample;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> java.io.File;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> java.io.IOException;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> java.util.Iterator;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> java.util.List;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> javax.servlet.ServletException;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> javax.servlet.http.HttpServlet;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> javax.servlet.http.HttpServletRequest;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> javax.servlet.http.HttpServletResponse;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> org.apache.commons.fileupload.FileItem;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> org.apache.commons.fileupload.disk.DiskFileItemFactory;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">import</span></strong><span style="color:black"> org.apache.commons.fileupload.servlet.ServletFileUpload;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#646464">@SuppressWarnings</span><span style="color:black">(</span><span style="color:#2a0ff">"serial"</span><span style="color:black">)</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><strong><span style="color:#7f055">public</span><span style="color:#7f055">class</span></strong><span style="color:black"> Upload </span><strong><span style="color:#7f055">extends</span></strong><span style="color:black"> HttpServlet { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">private</span></strong><span style="color:black"> String </span><span style="color:#00c0">uploadPath</span><span style="color:black"> = </span> <span style="color:#2a0ff">"D:\\temp"</span><span style="color:black">; </span><span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">上传文件的目录</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">private</span></strong><span style="color:black"> String </span><span style="color:#00c0">tempPath</span><span style="color:black"> = </span> <span style="color:#2a0ff">"d:\\temp\\buffer\\"</span><span style="color:black">; </span><span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">临时文件目录</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> File <span style="color:#00c0">tempPathFile</span><span style="color:black">;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:#646464">@SuppressWarnings</span><span style="color:black">(</span><span style="color:#2a0ff">"unchecked"</span><span style="color:black">)</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">public</span><span style="color:#7f055">void</span></strong><span style="color:black"> doPost(HttpServletRequest request, HttpServletResponse response)</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><strong><span style="color:#7f055">throws</span></strong><span style="color:black"> IOException, ServletException { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">try</span></strong><span style="color:black"> { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color:#3f7f5f">// Create a factory for disk-based file items</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>DiskFileItemFactory factory = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> DiskFileItemFactory();</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color:#3f7f5f">// Set factory constraints</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>factory.setSizeThreshold(4096); <span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">设置缓冲区大小，这里是</span><span style="color:#3f7f5f">4kb</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>factory.setRepository(<span style="color:#00c0">tempPathFile</span><span style="color:black">);</span><span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">设置缓冲区目录</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color:#3f7f5f">// Create a new file upload handler</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>ServletFileUpload upload = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> ServletFileUpload(factory);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color:#3f7f5f">// Set overall request size constraint</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>upload.setSizeMax(4194304); <span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">设置最大文件尺寸，这里是</span><span style="color:#3f7f5f">4MB</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>List&lt;FileItem&gt; items = upload.parseRequest(request);<span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">得到所有的文件</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>Iterator&lt;FileItem&gt; i = items.iterator();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><strong><span style="color:#7f055">while</span></strong><span style="color:black"> (i.hasNext()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>FileItem fi = (FileItem) i.next();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>String fileName = fi.getName();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><strong><span style="color:#7f055">if</span></strong><span style="color:black"> (fileName != </span><strong><span style="color:#7f055">null</span></strong><span style="color:black">) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>File fullFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(fi.getName());</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>File savedFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(</span><span style="color:#00c0">uploadPath</span><span style="color:black">, fullFile.getName());</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>fi.write(savedFile);</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>}</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>}</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>System.<em><span style="color:#00c0">out</span></em><span style="color:black">.print(</span><span style="color:#2a0ff">"upload succeed"</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> } <strong><span style="color:#7f055">catch</span></strong><span style="color:black"> (Exception e) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="color:#3f7f5f">// </span><span style="color:#3f7f5f">可以跳转出错页面</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>e.printStackTrace();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px">&nbsp;</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">public</span><span style="color:#7f055">void</span></strong><span style="color:black"> init() </span><strong><span style="color:#7f055">throws</span></strong><span style="color:black"> ServletException { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File uploadFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(</span><span style="color:#00c0">uploadPath</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <strong><span style="color:#7f055">if</span></strong><span style="color:black"> (!uploadFile.exists()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>uploadFile.mkdirs();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File tempPathFile = <strong><span style="color:#7f055">new</span></strong><span style="color:black"> File(</span><span style="color:#00c0">tempPath</span><span style="color:black">);</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> &nbsp;&nbsp;&nbsp; <strong><span style="color:#7f055">if</span></strong><span style="color:black"> (!tempPathFile.exists()) { </span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>tempPathFile.mkdirs();</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> }</span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">}</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

demo4.html

<table> 
 <tbody> 
  <tr> 
   <td style="background:rgb(230,230,230) none repeat scroll 0% 50%"> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">meta </span><span style="color:#7f07f">http-equiv</span><span style="color:black">=</span><span style="color:#2a0ff">"Content-Type" </span><span style="color:#7f07f">content</span><span style="color:black">=</span><span style="color:#2a0ff">"text/html; charset=GB18030"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span><span style="color:black">File upload</span><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">title</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">head</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#ff660">// action="fileupload"</span><span style="color:#ff660">对应</span><span style="color:#ff660">web.xml</span><span style="color:#ff660">中</span><span style="color:#ff660">&lt;servlet-mapping&gt;</span><span style="color:#ff660">中</span><span style="color:#ff660">&lt;url-pattern&gt;</span><span style="color:#ff660">的设置</span><span style="color:#ff660">.</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">form </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myform" </span><span style="color:#7f07f">action</span><span style="color:black">=</span><span style="color:#2a0ff">"fileupload" </span><span style="color:#7f07f">method</span><span style="color:black">=</span><span style="color:#2a0ff">"post"</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:#2a0ff">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:#7f07f">enctype</span><span style="color:black">=</span><span style="color:#2a0ff">"multipart/form-data"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> File:<span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"file" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"myfile"</span><span style="color:teal">&gt;&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">br</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;</span><span style="color:#3f7f7f">input </span><span style="color:#7f07f">type</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">name</span><span style="color:black">=</span><span style="color:#2a0ff">"submit" </span><span style="color:#7f07f">value</span><span style="color:black">=</span><span style="color:#2a0ff">"Commit"</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:black">&nbsp;&nbsp;&nbsp; </span> <span style="color:teal">&lt;/</span><span style="color:#3f7f7f">form</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">body</span><span style="color:teal">&gt;</span></span> 
    </div> 
    <div> 
     <span style="font-size:12px"><span style="color:teal">&lt;/</span><span style="color:#3f7f7f">html</span><span style="color:teal">&gt;</span></span> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

web.xml

2 下面说下JQUERY上传：

[commons-io-1.3.2.jar]: http://commons.apache.org/io/