jap+java+struts2文件上传到服务器

男娘i 2022-07-14 14:45 75阅读 0赞

直接上代码

jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%@ taglib uri="/struts-tags" prefix="s" %>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>上传文件</title>
        
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    	
    
      </head>
      
      <body>
        <form  action="<%=path %>/fileUp/fileUp.action" method="post" enctype="multipart/form-data">
        	<input type="file" name="picture"><br/>
        	<input type="submit" value="提交">
        </form>
      
      </body>
    </html>

java

package com.demo.fileup;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    
    import org.apache.struts2.ServletActionContext;
    
    import com.opensymphony.xwork2.ActionSupport;
    
    /**
     * 本类用于测试文件上传到服务器的功能
     * 
     * @author WuJieJecket
     * 
     *         1、jsp:fileUp.jsp 2、struts：struts-fileup.xml
     *         3、action:FileUpAction.java
     * 
     */
    @SuppressWarnings("serial")
    public class FileUpAction extends ActionSupport {
    	// 注意，file并不是指前端jsp上传过来的文件本身，而是文件上传过来存放在临时文件夹下面的文件
    	private File picture;
    
    	// 提交过来的file的名字
    	private String pictureFileName;
    
    	// 提交过来的file的MIME类型
    	private String pictureContentType;
    
    	public String toFileUp() {
    		return "success";
    	}
    	
    	/**
    	 * 文件上传
    	 * @return
    	 * @throws IOException
    	 */
    	public String fileUp() throws IOException {
    		final String root="/tmp/share";//绝对路径，从根目录开始-linux环境
    		final String  root1="d:/a";//绝对路径,从根目录开始-windows环境
    		final String  root2=ServletActionContext.getServletContext().getRealPath("upload");//相对路径，从项目webapp目录下开始
    		
    		File saved=new File(root,pictureFileName);//最终将文件保存到/upload下
    		
    		InputStream ins=null;	//文件输出流
    		OutputStream ous=null;	//文件输出流
    		try{
    			saved.getParentFile().mkdir();	//确保文件夹/upload存在
    			
    			ins=new FileInputStream(picture);	//读入临时文件
    			ous=new FileOutputStream(saved);	//写入到upload下
    			
    			byte[] b=new byte[1024];	//字节缓存
    			int len=0;
    			while((len=ins.read(b))!=-1){	//循环读入，直至结束
    				ous.write(b, 0, len);		//写入文件
    			}
    			
    		}catch (Exception e) {
    			// TODO: handle exception
    			e.printStackTrace();
    		}finally{
    			if(ous!=null)ous.close();	//关闭流
    			if(ins!=null)ins.close();	//关闭流
    		}
    		return "success";
    	}
    	
    	
    	public File getPicture() {
    		return picture;
    	}
    
    	public void setPicture(File picture) {
    		this.picture = picture;
    	}
    
    	public String getPictureFileName() {
    		return pictureFileName;
    	}
    
    	public void setPictureFileName(String pictureFileName) {
    		this.pictureFileName = pictureFileName;
    	}
    
    	public String getPictureContentType() {
    		return pictureContentType;
    	}
    
    	public void setPictureContentType(String pictureContentType) {
    		this.pictureContentType = pictureContentType;
    	}
    	
    	
    }

struts.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE struts PUBLIC
    	"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
    	"http://struts.apache.org/dtds/struts-2.1.7.dtd">
    	<struts>
    		
    		
    		
    		
    		<constant name="struts.multipart.saveDir" value="upload"/>
    		
    		<package name="fileUp" extends="struts-default" namespace="/fileUp">
    		
    		<action name="toFileUp" class="com.demo.fileup.FileUpAction" method="toFileUp">
    				<result name="success">/fileUp/toFileUp.jsp</result>
    			</action>	
    		
    			 
    			<action name="fileUp" class="com.demo.fileup.FileUpAction" method="fileUp">
    				<result name="success">/fileUp/fileUp.jsp</result>	
    			</action>
    		</package>	
    	</struts>

默认情况下，struts2下载文件是有大小限制的，只有2M

如果想提高上限，在struts.xml中做如下配置,单位是字节-这个是全局的

<constant name="struts.multipart.maxSize" value="1073741824"/>