Java实现文件上传至服务器的方法

2024-07-13 10:16:35

字体：大中小

来源：转载

供稿：网友

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

upload.jsp

代码；

<%@ page language="java" contentType="text/html; charset=UTF-8"%><html><head><title>using commons Upload to upload file </title></head><style>* { font-family: "宋体"; font-size: 14px }</style><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="提交" > <input type="reset" name="reset" value="重置" > </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;/** *  * @author XHW *  * @date 2011-7-26 *  */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());　　／／上传文件的保存路径  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"> <!-- <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" > --> </head>  <body> ${requestScope['upload.message'] } <a href="/upload/uploadFile.jsp" rel="external nofollow" >上传文件</a> </body></html>

web.xml

<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>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持VeVb武林网。

注：相关教程知识阅读请移步到JAVA教程频道。

上一篇：java实现多文件上传至本地服务器功能

下一篇：java实现客户端向服务器发送文件