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主题： [转帖]Java Web 文件上传

panpan.nie

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发表于：

2015-4-22 15:51:12 | [全部帖] [楼主帖]

楼主

在我们的web开发中，很多的时候都需要把本机的一些文件上传到web服务器上面去

如：一个BBS系统，当用户使用这是系统的时候，能把本机的一些图片，文档上传到服务器上面去。然后其他用户可以去下载这些文件，那么这样的话，我们可以自己编程实现文件的上传但是更好的方式是使用一些已有的组件帮助我们实现这种上传功能。

常用的上传组件：

Apache 的 Commons FileUpload

JavaZoom的UploadBean、jspSmartUpload

--------------------------------------------------------------------------------------------------

FileUpload下载地址：

http://commons.apache.org/fileupload/ 下载：commons-fileupload-1.2.2-bin.zip 得到：commons-fileupload-1.2.2.jar

http://commons.apache.org/io/ 下载：commons-io-1.4-bin.zip 得到：commons-io-1.4.jar

--------------------------------------------------------------------------------------------------

upload.jsp代码；

<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>using commons Upload to upload file </title>
</head>
<body>
<p align="center"> 请您选择需要上传的文件</p>
<form id="form1" name="form1" method="post" action="servlet/fileServlet" enctype="multipart/form-data">
<table border="0" align="center">
<tr>
<td>上传人：</td>
<td>
<input name="name" type="text" id="name" size="20" ></td>
</tr>
<tr>
<td>上传文件：</td>
<td><input name="file" type="file" size="20" ></td>
</tr>
<tr>
<td></td>
<td>
<input type="submit" name="submit" value="submit" >
<input type="reset" name="reset" value="reset" >
</td>
</tr>
</table>
</form>
</body>
</html>
--------------------------------------------------------------------------------------------------

FileUploadServlet.java代码：

package com.b510.example;
import java.io.File;
import java.io.IOException;
import java.util.*;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class FileUploadServlet extends HttpServlet {
      private static final long serialVersionUID = -7744625344830285257L;
      private ServletContext sc;
      private String savePath;
      public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
            doPost(request, response);
      }
      public void init(ServletConfig config) {
            // 在web.xml中设置的一个初始化参数
            savePath = config.getInitParameter("savePath");
            sc = config.getServletContext();
      }
      public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            request.setCharacterEncoding("UTF-8");
            DiskFileItemFactory factory = new DiskFileItemFactory();
            ServletFileUpload upload = new ServletFileUpload(factory);
            try {
                  List items = upload.parseRequest(request);
                  Iterator itr = items.iterator();
                  while (itr.hasNext()) {
                        FileItem item = (FileItem) itr.next();
                        if (item.isFormField()) {
                              System.out.println("表单参数名:" + item.getFieldName() + "，表单参数值:" + item.getString("UTF-8"));
                        } else {
                        if (item.getName() != null && !item.getName().equals("")) {
                              System.out.println("上传文件的大小:" + item.getSize());
                              System.out.println("上传文件的类型:" + item.getContentType());
                              // item.getName()返回上传文件在客户端的完整路径名称
                              System.out.println("上传文件的名称:" + item.getName());
                              File tempFile = new File(item.getName());
                              File file = new File(sc.getRealPath("/") + savePath, tempFile.getName());
                              item.write(file);
                              request.setAttribute("upload.message", "上传文件成功！");
                        }else{
                        request.setAttribute("upload.message", "没有选择上传文件！");
                  }
            }
      }
}catch(FileUploadException e){
e.printStackTrace();
} catch (Exception e) {
      e.printStackTrace();
      request.setAttribute("upload.message", "上传文件失败！");
}
request.getRequestDispatcher("/uploadResult.jsp").forward(request, response);
}
}
--------------------------------------------------------------------------------------------------

uploadResult.jsp代码；

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>uploadResult</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">

</head>
<body>
${requestScope['upload.message'] }
<a href="/upload/uploadFile.jsp">上传文件</a>
</body>
</html>
--------------------------------------------------------------------------------------------------

web.xml代码：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>FileUploadServlet</servlet-name>
<servlet-class>com.b510.example.FileUploadServlet</servlet-class>
＜！--设置初始化参数--＞
<init-param>
<param-name>savePath</param-name>
<param-value>uploads</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>FileUploadServlet</servlet-name>
<url-pattern>/servlet/fileServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
<welcome-file>uploadFile.jsp</welcome-file>
</welcome-file-list>
</web-app>

该贴被panpan.nie编辑于2015-4-22 15:57:31