commons-fileupload-1.2.2实现文件上传

准备工作：

两个jar包

commons-fileupload-1.2.2  下载地址：点击打开链接

commons-io-2.4  下载地址点击打开链接

jsp代码:

[html] view plaincopy

1. <form action="Upload" method="post" enctype="multipart/form-data">    
2. 用户名：<input type="text" name="username" /><br/>        
3. 文件：<input type="file" name="file1" /><br/>      
4. <input type="submit" value="上传" /><br/>       
5. </form>    

Servlet代码:

[java] view plaincopy

1. package fileupload;  
2.   
3. import java.io.FileOutputStream;  
4. import java.io.IOException;  
5. import java.io.InputStream;  
6. import java.util.List;  
7.   
8. import javax.servlet.ServletException;  
9. import javax.servlet.http.HttpServlet;  
10. import javax.servlet.http.HttpServletRequest;  
11. import javax.servlet.http.HttpServletResponse;  
12.   
13. import org.apache.commons.fileupload.FileItem;  
14. import org.apache.commons.fileupload.disk.DiskFileItemFactory;  
15. import org.apache.commons.fileupload.servlet.ServletFileUpload;  
16.   
17. /** 
18.  * Servlet implementation class Upload 
19.  */  
20. public class Upload extends HttpServlet {  
21.     private static final long serialVersionUID = 1L;  
22.   
23.   
24.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
25.         doPost(request,response);  
26.     }  
27.   
28.     /** 
29.      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
30.      */  
31.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
32.           
33.         try {  
34.                // 1 建立工厂对象  
35.   
36.                DiskFileItemFactory factory = new DiskFileItemFactory();  
37.   
38.                 // 2 获取解析器  
39.   
40.                ServletFileUpload upload = new ServletFileUpload(factory);  
41.   
42.                // 3 对请求对象进行解析，得到存放FileItem的list对象  
43.   
44.                List<FileItem> list = upload.parseRequest(request);  
45.   
46.                 // 4 对FileItem对象列表进行迭代  
47.   
48.                for (FileItem item : list) {  
49.   
50.                   // 普通输入项  
51.   
52.                   if (item.isFormField()) {   
53.   
54.                       String paramName = item.getFieldName();  
55.                       paramName=new String(paramName.getBytes(),"utf-8");  
56.                       String paramValue = item.getString();  
57.                       // 乱码问题的彻底解决  
58.                       paramValue = new String(paramValue.getBytes("ISO-8859-1"),"utf-8");  
59.                       System.out.println("普通输入项：" + paramName + " = " + paramValue);  
60.   
61.                       //获得用户名  
62.   
63.                       //String name = paramValue;     
64.   
65.                   }    
66.   
67.                   // 上传文件  
68.   
69.                   else {  
70.                       String fileName = item.getName();  
71.                       fileName=new String(fileName.getBytes(),"utf-8");  
72.                       System.out.println("filename = " + fileName);  
73.   
74.                       //如果上传的是文件路径，就将文件路径打印出来  
75.                       fileName = fileName.substring(fileName.lastIndexOf("\\") + 1);  
76.   
77.                       System.out.println("filename = " + fileName);  
78.   
79.                       InputStream in = item.getInputStream();  
80.   
81.                       byte[] buffer = new byte[1024*4];  
82.   
83.                       int len = 0;  
84.   
85.                        FileOutputStream fos = new FileOutputStream("D:\\"  
86.   
87.                              + fileName);    
88.   
89.                       while ((len = in.read(buffer)) > 0) {  
90.                          fos.write(buffer, 0, len);  
91.   
92.                       }  
93.   
94.                        fos.flush();  
95.   
96.                       in.close();  
97.   
98.                       fos.close();  
99.   
100.                       request.setAttribute("message", "上传成功！！！");  
101.   
102.                   }  
103.   
104.                }  
105.   
106.             } catch (Exception e) {  
107.   
108.                e.printStackTrace();  
109.   
110.                request.setAttribute("message", "上传失败！！");  
111.   
112.            }  
113.   
114.            request.getRequestDispatcher("/message.jsp").forward(request, response);  
115.           
116.     }  
117.   
118. }