Servlet实现文件上传（简单）（一）

 1、、使用到的jar包，为apache的一个子项目
 此commons-fileupload-1.2.2需要以下commons-io-2.0.1的支持
 
2、页面展示fileUpload.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
 
    <title>My JSP 'fileUpload.jsp' starting page</title>
 
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">   
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
 
  <body>
    <form action="UploadServlet" method="post" enctype="multipart/form-data">
    username: <input type="text" name="username"><br>
    file: <input type="file" name="file"><br>
    file2: <input type="file" name="file2"><br>
 
    <input type="submit" value="submit">
    </form>
3、servlet处理UploadServlet.java
package com.shengsiyuan.servlet;
 
import java.io.File;
import java.io.IOException;
import java.util.List;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
 
public class UploadServlet extends HttpServlet
{
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException
    {
        DiskFileItemFactory factory = new DiskFileItemFactory();
 
        String path = req.getRealPath("/upload");//定义上传文件的路径为webroot下的upload文件
 
        factory.setRepository(new File(path));
        factory.setSizeThreshold(1024 * 1024);//上传文件的大小为1024*1024字节，也就是1兆
 
        ServletFileUpload upload = new ServletFileUpload(factory);
 
        try
        {
            List<FileItem> list = (List<FileItem>)upload.parseRequest(req);
 
            for(FileItem item : list)
            {
                String name = item.getFieldName();
 
                if(item.isFormField())//如果上传的是文本域的话，对文本与进行处理
                {
                    String value = item.getString();
 
                    System.out.println(name + "=" + value);
 
                    req.setAttribute(name, value);
                }
                else//如果上传的是文件
                {
                    String value = item.getName();
 
                    int start = value.lastIndexOf("\\");//查找文件名称，从最后一个\开始查找
                    String fileName = value.substring(start + 1);//这时候对应的文件应该从1开始，因为0是\
 
                    req.setAttribute(name, fileName);
 
                    item.write(new File(path, fileName));//将文件写到磁盘上来，path为上传的路径，filename为文件名称
                    //以下是自己写的操作输入输出流的代码，当然也可以不使用下面的写法
//                   
//                    OutputStream os = new FileOutputStream(new File(path, fileName));
//                   
//                    InputStream is = item.getInputStream();
//                   
//                    byte[] buffer = new byte[400];
//                   
//                    int length = 0;
//                   
//                    while((length = is.read(buffer)) != -1)
//                    {
//                        os.write(buffer, 0, length);
//                    }
//                   
//                    is.close();
//                    os.close();
                }
            }
 
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
 
        req.getRequestDispatcher("fileUploadResult.jsp").forward(req, resp);
    }
}
4、结果页fileUploadResult.jsp
<%@ page language="java" import="java.util.*, java.io.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
 
    <title>My JSP 'fileUploadResult.jsp' starting page</title>
 
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">   
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
 
  </head>
 
  <body>
 
   <%
   /*
       InputStream is = request.getInputStream();
 
    BufferedReader br = new BufferedReader(new InputStreamReader(is));
  
    String buffer = null; 
 
    while(null != (buffer = br.readLine()))
    {
        out.print(buffer + "<br>");
    }
 
    br.close();
    is.close();
   */
   %>
 
   username : ${requestScope.username }<br>
   file: ${requestScope.file}<br>
   file2: ${requestScope.file2 }<br>
  </body>
</html>
5、页面展示
  结果展示




posted @ 2013-12-25 14:18  Tim&Blog  阅读(538)  评论(0)  编辑  收藏  举报