Struts2
       
      
       org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
       
      
      
      
       Struts2
       
      
       /*
       
     

import java.io.File;import org.apache.commons.io.FileUtils;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class FileUpload extends ActionSupport {    // 对应表单：    private File file1;    // 文件名    private String file1FileName;    // 文件的类型(MIME)    private String file1ContentType;    public void setFile1(File file1) {        this.file1 = file1;    }    public void setFile1FileName(String file1FileName) {        this.file1FileName = file1FileName;    }    public void setFile1ContentType(String file1ContentType) {        this.file1ContentType = file1ContentType;    }    @Override    public String execute() throws Exception {        /****** 拿到上传的文件，进行处理 ******/        // 把文件上传到upload目录        // 获取上传的目录路径        String path = ServletActionContext.getServletContext().getRealPath(                "/upload");        // 创建目标文件对象        File destFile = new File(path, file1FileName);        // 把上传的文件，拷贝到目标文件中        FileUtils.copyFile(file1, destFile);        return SUCCESS;    }}

package com.yif.fileupload;import java.io.File;import java.io.InputStream;import java.io.UnsupportedEncodingException;import java.net.URLEncoder;import java.util.Map;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionSupport;public class DownAction extends ActionSupport {        /*************1. 显示所有要下载文件的列表*********************/    public String list() throws Exception {        //得到upload目录路径        String path = ServletActionContext.getServletContext().getRealPath("/upload");        // 目录对象        File file  = new File(path);        // 得到所有要下载的文件的文件名        String[] fileNames =  file.list();        // 保存        ActionContext ac = ActionContext.getContext();        // 得到代表request的map (第二种方式)        Map
     
       request= (Map
      
       ) ac.get("request");        request.put("fileNames", fileNames);        return "list";    }        /*************2. 文件下载*********************/    private String fileName;    public void setFileName(String fileName) {        // 处理传入的参数中问题(get提交)        try {            fileName = new String(fileName.getBytes("ISO8859-1"),"UTF-8");        } catch (UnsupportedEncodingException e) {            throw new RuntimeException(e);        }        // 把处理好的文件名，赋值        this.fileName = fileName;    }        //2. 下载提交的业务方法 (在struts.xml中配置返回stream)    public String down() throws Exception {        return "download";    }        // 3. 返回文件流的方法    public InputStream getAttrInputStream(){        return ServletActionContext.getServletContext().getResourceAsStream("/upload/" + fileName);    }        // 4. 下载显示的文件名（浏览器显示的文件名）    public String getDownFileName() {        // 需要进行中文编码        try {            fileName = URLEncoder.encode(fileName, "UTF-8");        } catch (UnsupportedEncodingException e) {            throw new RuntimeException(e);        }        return fileName;    }    }
      
     

     
         
              
               
                   
                    
                        
                         
         txt,jpg,jar                
                     
                    
        
         /e/success.jsp
                    
                    
        
         /e/error.jsp
                
               
                   
                    
        
         /e/list.jsp
                    
                    
                        
                         
         application/octet-stream                
                         
         attrInputStream                
                         
         attachment;filename=${downFileName}                
                         
         1024