文件下载

[java] view plaincopyprint?

1. js:  
2. //下载图片  
3. function downloadFileT(path, fname){  
4.     $(‘#fileDownFrame‘).form(‘submit‘, {  
5.         url :‘<%=request.getContextPath()%>/down/downLoadFile.action?filename=‘+encodeURI(encodeURI(fname))+‘&filePath=‘+encodeURI(encodeURI(path)),  
6.         dataType : ‘text/xml‘,  
7.         async:false,  
8.         success : function(data) {  
9.              。。。。。  
10.         }  
11.     });  
12.  }   
13.   
14. html:  
15.  <form id="fileDownFrame" style="display:none; visibility:hidden;" method="post"></form>  
16.   
17.   
18. action:  
19. /** 
20.      * 下载附件 
21.      * @param request 
22.      * @param response 
23.      * @throws UnsupportedEncodingException  
24.      * @throws IOException  
25.      */  
26.     @Action("downLoadFile")  
27.     public void downLoadFile() throws IOException {  
28.         HttpServletRequest request=ServletActionContext.getRequest();  
29.         HttpServletResponse response=ServletActionContext.getResponse();  
30.         //response.setContentType("text/Xml;charset=utf-8");  
31.         response.setContentType("application/octet-stream");  
32.         JSONObject json=new JSONObject();  
33.         try{  
34.             String path= URLDecoder.decode(request.getParameter("filePath"),"utf-8");//从页面获取要下载的文件的相对路径  
35.             String filename= URLDecoder.decode(request.getParameter("filename"),"utf-8");  
36.             if(!"".equals(path)){  
37.                 path=path.replaceAll("\\\\", "/");  
38.                 File file=new File(request.getSession()  
39.                         .getServletContext().getRealPath("/")+path);//构造要下载的文件    
40.                 if(file.exists()){  
41.                     InputStream ins=new FileInputStream(file);//构造一个读取文件的IO流对象  
42.                     BufferedInputStream bins=new BufferedInputStream(ins);//放到缓冲流里面  
43.                     OutputStream outs=response.getOutputStream();//获取文件输出IO流  
44.                     BufferedOutputStream bouts=new BufferedOutputStream(outs);  
45.                     response.setContentType("application/x-msdownload");//设置response内容的类型  
46.                     response.addHeader("Content-Length", "" + file.length());  
47.                     response.setHeader("Content-disposition","attachment;filename="+ new String( filename.getBytes("gb2312"), "ISO8859-1" ));//设置头部信息  
48.                     int bytesRead = 0;  
49.                     int size=(int)file.length();  
50.                     byte[] buffer = new byte[size];  
51.                     //开始向网络传输文件流  
52.                     while ((bytesRead = bins.read(buffer, 0, buffer.length)) != -1) {  
53.                         bouts.write(buffer, 0, bytesRead);  
54.                     }  
55.                     bouts.flush();//这里一定要调用flush()方法  
56.                     ins.close();  
57.                     bins.close();  
58.                     outs.close();  
59.                     bouts.close();  
60.                    // json.put("result", "success");  
61.                 }else{  
62.                     response.reset();  
63.                     json.put("result", "none");  
64.                     response.getWriter().print(json.toString());  
65.                     System.out.println("下载的文件不存在");  
66.                 }  
67.             }else{  
68.                 json.put("result", "wrong");  
69.                 response.getWriter().print(json.toString());  
70.                 System.out.println("下载文件时参数错误");  
71.             }  
72.         }catch (Exception e) {  
73.             json.put("result", "error");  
74.             response.getWriter().print(json.toString());  
75.             e.printStackTrace();  
76.         }  
77.     }  

原文出自：http://blog.csdn.net/lishuangzhe7047/article/details/43560447