使用servlet实现文件上传

 1 package com.zhanghaobo.fileupload;
 2 
 3 import java.io.File;
 4 import java.io.IOException;
 5 import java.util.List;
 6 
 7 import javax.servlet.ServletException;
 8 import javax.servlet.http.HttpServlet;
 9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 
12 import org.apache.commons.fileupload.FileItem;
13 import org.apache.commons.fileupload.disk.DiskFileItemFactory;
14 import org.apache.commons.fileupload.servlet.ServletFileUpload;
15 
16 public class UploadServlet extends HttpServlet {
17     @Override
18     protected void doPost(HttpServletRequest req, HttpServletResponse resp)
19             throws ServletException, IOException {
20         DiskFileItemFactory factory=new DiskFileItemFactory();
21         
22         String realPath=req.getRealPath("/upload");
23         
24         //物理缓存存放地
25         factory.setRepository(new File(realPath));
26         
27         //设置内存存放大小
28         factory.setSizeThreshold(1024*1024);
29         
30         ServletFileUpload upload=new ServletFileUpload(factory);
31         //FileItem 可以表示文件(file)也可以表示文本域（form item） 有一个isFormField方法判断是否是表单
32         try{
33             List<FileItem> list=(List<FileItem>)upload.parseRequest(req);
34             for(FileItem item:list){
35                 String name=item.getFieldName();
36                 if(item.isFormField()){
37                     String value=item.getString();
38                     req.setAttribute(name, value);
39                 }else{
40                     String value=item.getName();
41                     int start=value.lastIndexOf("\");
42                     String fileName=value.substring(start+1);
43                     req.setAttribute(name, fileName);
44                     //上传文件存放地
45                     item.write(new File(realPath,fileName));
46                 }
47             }
48         }catch(Exception e){
49             e.printStackTrace();
50         }
51         
52         req.getRequestDispatcher("showResult.jsp").forward(req, resp);
53     }
54 }

 1 public class UploadServlet extends HttpServlet {
 2     @Override
 3     protected void doPost(HttpServletRequest req, HttpServletResponse resp)
 4             throws ServletException, IOException {
 5         DiskFileItemFactory factory=new DiskFileItemFactory();
 6         
 7         String realPath=req.getRealPath("/upload");
 8         
 9         //物理缓存存放地
10         factory.setRepository(new File(realPath));
11         
12         //设置内存存放大小
13         factory.setSizeThreshold(1024*1024);
14         
15         ServletFileUpload upload=new ServletFileUpload(factory);
16         //FileItem 可以表示文件(file)也可以表示文本域（form item） 有一个isFormField方法判断是否是表单
17         try{
18             List<FileItem> list=(List<FileItem>)upload.parseRequest(req);
19             for(FileItem item:list){
20                 String name=item.getFieldName();
21                 if(item.isFormField()){
22                     String value=item.getString();
23                     req.setAttribute(name, value);
24                 }else{
25                     String value=item.getName();
26                     int start=value.lastIndexOf("\");
27                     String fileName=value.substring(start+1);
28                     req.setAttribute(name, fileName);
29                     
30                     //上传文件存放地
31 //                    item.write(new File(realPath,fileName));
32                     
33                     InputStream is=item.getInputStream();
34                     
35                     long all=item.getSize();
36                     
37                     OutputStream os=new FileOutputStream(new File(realPath,fileName));
38                     
39                     byte[] buffer=new byte[400];
40                     
41                     int length=0;
42                     int l=0;
43                     DecimalFormat df=new DecimalFormat("#.00");
44                     while(-1!=(length=is.read(buffer))){
45                         os.write(buffer,0,length);
46                         l+=length;
47                         System.out.println("总大小"+all+""+"进度："+(df.format((double)l/all*100))+"%"+"已经读取的大小"+l);
48                     }
49                     
50                     is.close();
51                     os.close();
52                     
53                 }
54             }
55         }catch(Exception e){
56             e.printStackTrace();
57         }
58         
59         req.getRequestDispatcher("showResult.jsp").forward(req, resp);
60     }
61 }