文件上传与下载-蒲公英云

一）、文件上传（多文件，单文件）

（1）、上传单个文件：

jsp页面：

<form action = "login.action" method = "post" enctype = "multipart/form-data">
        账号：<input name = "name" type = "text"><br><br>
    照片：<input name = "photo" type = "file"><br><br>
    <input type ="submit" value = "提交">

Action代码：

package com.action;
import java.io.File;
import java.io.IOException;
import org.apache.commons.io.FileUtils;
public class LoginAction {
    private String name ;
    private File photo;
    private String photoFileName;
    private String photoContentType;
    public String execute(){
        System.out.println(photoFileName);
        System.out.println(photoContentType);
        File destFile = new File("C:\\Users\\Administrator\\Pictures\\struts\\"+photoFileName);
        try {
            FileUtils.copyFile(photo, destFile);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "success";
    }

到此为止简单的文件上传已经完成，但是，通常情况下文件不是保存在某个指定的盘下，而是保存在项目文件下，修改如下：

File destFile = new File(ServletActionContext.getServletContext().getRealPath("/upload/"+photoFileName));

(2)、上传多个文件：只需要将上例中的与文件相关的属性改成数组形式即可，然后将上传的方法，改为操作数组。

jsp代码：

<form action = "login.action" method = "post" enctype = "multipart/form-data">
        账号：<input name = "name" type = "text"><br><br>
    照片：<input name = "photo" type = "file"><br><br>
    照片：<input name = "photo" type = "file"><br><br>
    <input type ="submit" value = "提交"> 
     </form>

Action代码：

import org.apache.struts2.ServletActionContext;
public class LoginAction {
    private String name ;
    private File[] photo;
    private String[] photoFileName;
    private String[] photoContentType;
    public String execute(){
//        System.out.println(photoFileName);
//        System.out.println(photoContentType);
//        File destFile = new File("C:\\Users\\Administrator\\Pictures\\struts\\"+photoFileName);
        for (int i = 0; i < photo.length; i++) {
            try {
                 File destFile = new File(ServletActionContext.getServletContext().getRealPath("/upload/"+photoFileName[i]));
                FileUtils.copyFile(photo[i], destFile);
            } catch (IOException e) {
                System.out.println("execute exception");
            }            
        }
        return "success";
    }

(3)、限制文件名、类型、大小：

（1）、限制文件名：

String filename = ServletActionContext.getServletContext().getRealPath("/upload/"
                          +UUID.randomUUID().toString()
                          +photoFileName.substring(photoFileName.lastIndexOf(".")));
                 File destFile = new File(filename);
                FileUtils.copyFile(photo, destFile);

（2）、限制文件类型：（Action必须继承ActionSupport类！！！）

struts.xml文件配置：

<package name = "default" namespace = "/" extends = "struts-default">
       <action name = "login" class = "com.action.LoginAction">
          <result name = "success">/ok.jsp</result>
          <result name = "input">/index.jsp</result>
          <interceptor-ref name="fileUpload">
             <param name="allowedTypes">
                 image/png,image/gif,image/jpeg,image/jpg
             </param>
          </interceptor-ref>
          <interceptor-ref name="defaultStack"/>
       </action>
    </package>

自定义消息配置文件：massage.properties

struts.messages.error.content.type.not.allowed=\u4E0A\u4F20\u6587\u6863\u7C7B\u578B\u4E0D\u6B63\u786E {1}

还需要在struts.xml中进行常量配置：

<constant name="struts.custom.i18n.resources" value="massage"></constant>

（3）限制文件大小：

自定义消息配置：

struts.messages.error.file.too.large=\u60A8\u4E0A\u4F20\u7684\u6587\u4EF6{1} \u8D85\u8FC7\u6700\u5927\u9650\u5236

struts.xml中添加：（大小自己定义）

<param name="maximumSize">
                1048576
             </param>

（二）、文件下载：

准备jsp页面

<a href = "download.action">下载</a>

准备Aciton代码：

package com.action;
import java.io.InputStream;
import org.apache.struts2.ServletActionContext;
public class DownLoadAction {
   private String filename;
   private InputStream input;
   public String execute (){
       filename = "1.png";
      input =  ServletActionContext.getServletContext().getResourceAsStream("/upload/"+filename);
       return "success";
   }

读取服务器端指定的文件，将此文件以输出流的方式响应给客户端。

Action的默认返回类型是“转发”，必须改成”流“的形式向客户端输出。

struts.xml文件配置：

<action name = "download" class = "com.action.DownLoadAction">
         <result name = "success" type = "stream">
            <param name="inputName">input</param>
            <param name = "contentDisposition" >attachment;filename=${filename}</param>
         </result>
       </action>

文件名中午乱码问题

修改Action中的代码为：

public String execute () throws Exception{
       filename = "呵呵.png";
        input =  ServletActionContext.getServletContext().getResourceAsStream("/upload/"+filename);
        filename = URLEncoder.encode(filename,"utf-8");
       return "success";
   }

-——————————————————————-

设置文件名：

/*
     * 创建文件名字
     */
    public String generateFileName(String fileName){
        String formateDate = new SimpleDateFormat("yyMMddHHmmss").format(new Date());
        int random = new Random().nextInt(10000);
        int position = fileName.lastIndexOf(".");
        String subStr = fileName.substring(position);
        return formateDate+random+subStr;
    }

-——————————————————————————————

文件上传：

private File photo;  //获取上传照片
    private String photoFileName;  //获取上传照片名
    private String photoContentType;  //获取上传照片类型
    /** 添加商品 */
    public String addMerchandise() {
        InputStream inputStream = null;
        OutputStream outputStream = null;
        /** 目标文件路径*/
        String dir = ServletActionContext.getServletContext().getRealPath("/Picture");
        /** 新文件名 */
        String newName = generateFileName(photoFileName);
        /** 目标文件 */
        File targetPhoto = new File(dir+"/"+newName);
        try {
            inputStream = new FileInputStream(photo);
            outputStream = new FileOutputStream(targetPhoto);
            byte[] bytes = new byte[1024];
            Integer r = 0;
            while(( r = inputStream.read(bytes,0,1024)) != -1 ) {
                outputStream.write(bytes, 0, r);
            }
            bookInfo.setPicture("/Picture/"+newName);
            bookInfo.setCategory(merchandiseService.loadCategory(category));
            merchandiseService.addMerchandise(bookInfo);
            return browseMerchandise();
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
                try {
                    if(inputStream != null) inputStream.close();
                    if(outputStream != null) outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
        }
        return "sorry";
    } 
    /*
     * 创建文件名字
     */
    public String generateFileName(String fileName){
        String formateDate = new SimpleDateFormat("yyMMddHHmmss").format(new Date());
        int random = new Random().nextInt(10000);
        int position = fileName.lastIndexOf(".");
        String subStr = fileName.substring(position);
        return formateDate+random+subStr;
    }