图片上传最终版本

1. SERVLET
3. package com.bjsxt.shopping.servlet;
5. import java.io.File;
6. import java.io.IOException;
7. import java.io.PrintWriter;
8. import java.util.Iterator;
9. import java.util.List;
10. import javax.servlet.ServletConfig;
11. import javax.servlet.ServletException;
12. import javax.servlet.http.HttpServlet;
13. import javax.servlet.http.HttpServletRequest;
14. import javax.servlet.http.HttpServletResponse;
15. import org.apache.commons.fileupload.FileItem;
16. import org.apache.commons.fileupload.FileUploadException;
17. import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
18. import org.apache.commons.fileupload.disk.DiskFileItemFactory;
19. import org.apache.commons.fileupload.servlet.ServletFileUpload;
21. public class FileUploadServlet extends HttpServlet
22. {
23.     //定义成员变量来记录上传的路径
24.     private String upLoadPath="";
25.     @Override
26. //    重写init(ServletConfig config)方法（不是void init()）来取得WEB.XML的值
27.     public void init(ServletConfig config) throws ServletException
28.     {
29.         this.upLoadPath=config.getInitParameter("upload");
30.     }
32.     private static final long serialVersionUID = 1L;
34.     public FileUploadServlet()
35.     {
36.         super();
37.     }
39.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
40.     {
41.         this.doPost(request, response);
42.     }
44.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
45.     {
46.         request.setCharacterEncoding("utf-8");
47.         int id = -1;
48.         final long MAX_SIZE = 300 * 1024 * 1024;// 设置上传文件最大值
49.         // 允许上传的文件格式的列表
50.         final String[] allowedExt = new String[]{"jpg", "jpeg", "gif", "txt", "doc", "mp3", "wma", "m4a", "rar", "zip"};
51.         response.setContentType("text/html");
52.         // 设置字符编码为UTF-8, 统一编码，处理出现乱码问题
53.         response.setCharacterEncoding("UTF-8");
54.         // 实例化一个硬盘文件工厂,用来配置上传组件ServletFileUpload
55.         DiskFileItemFactory dfif = new DiskFileItemFactory();
56.         dfif.setSizeThreshold(4096);// 设置上传文件时用于临时存放文件的内存大小,这里是4K.多于的部分将临时存在硬盘
57.         dfif.setRepository(new File(request.getRealPath("/") + "ImagesUploadTemp"));// 设置存放临时文件的目录,web根目录下的ImagesUploadTemp目录
59.         // 用以上工厂实例化上传组件
60.         ServletFileUpload sfu = new ServletFileUpload(dfif);
61.         // 设置最大上传大小
62.         sfu.setSizeMax(MAX_SIZE);
63.         PrintWriter out = response.getWriter();
64.         // 从request得到所有上传域的列表
65.         List fileList = null;
66.         try
67.         {
68.             fileList = sfu.parseRequest(request);
69.         } catch (FileUploadException e)
70.         {// 处理文件尺寸过大异常
71.             if (e instanceof SizeLimitExceededException)
72.             {
73.                 out.println("文件尺寸超过规定大小:" + MAX_SIZE + "字节<p />");
74.                 out.println("<a href=/"./admin/manager/productlist.jsp/" >返回</a>");
75.                 return;
76.             }
77.             e.printStackTrace();
78.         }
79.         // 没有文件上传
80.         if (fileList == null || fileList.size() == 0)
81.         {
82.             out.println("请选择上传文件<p />");
83.             out.println("<a href=/"./admin/manager/productlist.jsp/" >返回</a>");
84.             return;
85.         }
86.         // 得到所有上传的文件
87.         Iterator fileItr = fileList.iterator();
88.         // 循环处理所有文件
89.         while (fileItr.hasNext())
90.         {
91.             FileItem fileItem = null;
92.             String path = null;
93.             long size = 0;
94.             // 得到当前文件
95.             fileItem = (FileItem) fileItr.next();
96.             // 忽略简单form字段而不是上传域的文件域(<input type="text" />等)
97.             if (fileItem != null && fileItem.isFormField())
98.             {
99.                 if (fileItem.getFieldName().equals("id"))
100.                 {
101.                     id = Integer.parseInt(fileItem.getString());
102.                 }
103.             }
104.             if (fileItem != null && !fileItem.isFormField())
105.             {
106.                 // 得到文件的完整路径
107.                 path = fileItem.getName();
108.                 // 得到文件的大小
109.                 size = fileItem.getSize();
110.                 if ("".equals(path) || size == 0)
111.                 {
112.                     out.println("请选择上传文件<p />");
113.                     out.println("<a href=/"./admin/manager/productlist.jsp/" >返回</a>");
114.                     return;
115.                 }
116.                 // 得到去除路径的文件名
117.                 String t_name = path.substring(path.lastIndexOf("//") + 1);
118.                 // 得到文件的扩展名(无扩展名时将得到全名)
119.                 String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1);
120.                 // 拒绝接受规定文件格式之外的文件类型
121.                 int allowFlag = 0;
122.                 int allowedExtCount = allowedExt.length;
123.                 for (; allowFlag < allowedExtCount; allowFlag++)
124.                 {
125.                     if (allowedExt[allowFlag].equals(t_ext))
126.                         break;
127.                 }
128.                 if (allowFlag == allowedExtCount)
129.                 {
130.                     out.println("请上传以下类型的文件<p />");
131.                     for (allowFlag = 0; allowFlag < allowedExtCount; allowFlag++)
132.                         out.println("*." + allowedExt[allowFlag] + "   ");
133.                     out.println("<p /><a href=/"./admin/manager/productlist.jsp/" >返回</a>");
134.                     return;
135.                 }
137.                 // long now = System.currentTimeMillis();
138.                 // 根据系统时间生成上传后保存的文件名
139.                 // String prefix = String.valueOf(now);
140.                 // 保存的最终文件完整路径,保存在web根目录下的ImagesUploaded目录下
141.                 // String u_name = request.getRealPath("/") + "ImagesUploaded/"
142.                 // + prefix + "." + t_ext;
143.                 //String filename = t_name;
144.                 // System.out.println(t_name);
145.                 try
146.                 {
147.                     // 保存文件到C://upload目录下
148.                     //统一将文件的扩展名改为　jpg　方便在页面中显示
149.                     fileItem.write(new File(upLoadPath + id + "." + "jpg"));
150.                     // System.out.println(filename);
151.                     out.println("文件上传成功. 已保存到: " + upLoadPath + id + "." + "jpg" + "   文件大小: " + size + "字节<p />");
152.                     out.println("<a href=/"./admin/manager/productlist.jsp/" >继续上传</a>");
153.                 } catch (Exception e)
154.                 {
155.                     e.printStackTrace();
156.                 }
157.             }
158.         }
159.     }
160. }
162. WEB.XML中写入下面的内容：
163.   <servlet>
164.     <description>This is the description of my J2EE component</description>
165.     <display-name>This is the display name of my J2EE component</display-name>
166.     <servlet-name>FileUploadServlet</servlet-name>
167.     <servlet-class>com.bjsxt.shopping.servlet.FileUploadServlet</servlet-class>
168.     <init-param>
169.         <param-name>upload</param-name>
170.         <param-value>E://workspace//MyProjest//Shopping//WebRoot//images//product//</param-value>
171.     </init-param>
172.   </servlet>
175. 其实最好的方法是增加一下属性文件，把要上传的路径写到该文件中，要上传时再从中读取这个路径