[TOC]
Servlet 上传图片
预备
需求包
commons-fileupload -用于上传
jstl -用于jsp页面遍历
servlet-api -使用servlet
pom
???<dependencies> ???????<dependency> ???????????<groupId>commons-fileupload</groupId> ???????????<artifactId>commons-fileupload</artifactId> ???????????<version>1.3.2</version> ???????</dependency> ???????<dependency> ???????????<groupId>jstl</groupId> ???????????<artifactId>jstl</artifactId> ???????????<version>1.2</version> ???????</dependency> ???????<dependency> ???????????<groupId>javax.servlet</groupId> ???????????<artifactId>javax.servlet-api</artifactId> ???????????<version>3.1.0</version> ???????</dependency> ???</dependencies>前端代码
<%@ page language="java" contentType="text/html; charset=UTF-8" ???pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><!DOCTYPE html><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>上传Demo</title></head><body> ???<form action="uploadServlet" method="post" ???????enctype="multipart/form-data"> ???????上传文件：<input type="file" name="file"><br/> ???????上传文件：<input type="file" name="file2"><br/> ????????<input type="submit" /> ???</form> ???<c:forEach items="${pics }" var="p"> ???<img src="heads/${p }" /> ???</c:forEach></body></html>后端处理代码
package com;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;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;@WebServlet("/uploadServlet")public class uploadServlet extends HttpServlet { ???private static final long serialVersionUID = 1L; ???public uploadServlet() { ???????super(); ???} ???protected void doGet(HttpServletRequest request, HttpServletResponse response) ???????????throws ServletException, IOException { ???????response.sendRedirect("index.jsp"); ???} ???protected void doPost(HttpServletRequest request, HttpServletResponse response) ???????????throws ServletException, IOException { ???????// 是否是多功能表单 ???????boolean isMultipart = ServletFileUpload.isMultipartContent(request); ???????if (!isMultipart) { ???????????return; ???????} ???????// 目标服务端目录 ???????String path = request.getSession().getServletContext().getRealPath("/heads"); ???????// String path="D:/heads"; ???????File file = new File(path); ???????// 如果目录不存在就创建目录 ???????if (!file.exists() && !file.isDirectory()) { ???????????file.mkdirs(); ???????} ???????// 接受文件列表 ???????List piclist = new ArrayList(); // 放上传的图片名 ???????DiskFileItemFactory factory = new DiskFileItemFactory(); ???????ServletFileUpload upload = new ServletFileUpload(factory); ???????upload.setHeaderEncoding("UTF-8"); // 处理中文问题 ???????upload.setSizeMax(1024 * 1024 * 5); // 限制文件大小5M ???????try { ???????????// 得到所有表单元素 ???????????List<FileItem> fileItems = upload.parseRequest(request); // 解码请求 ???????????for (FileItem item : fileItems) { ???????????????System.out.println(item); ???????????????// 有可能是 文件，也可能是普通文字 ???????????????if (item.isFormField()) { // 这个选项是 文字 ???????????????????System.out.println("表单值为：" + item.getString()); ???????????????} else { ???????????????????// 是文件 ???????????????????String fileName = item.getName(); ???????????????????System.out.println("文件名是:" + fileName); // 文件名 ???????????????????item.write(new File(path, fileName)); ???????????????????if (fileName.endsWith(".jpg") || fileName.endsWith(".png") || fileName.endsWith(".bmp") || fileName.endsWith(".ico") || fileName.endsWith(".gif")) { ???????????????????????piclist.add(fileName); // 把图片放入集合 ???????????????????} ???????????????} ???????????} ???????} catch (Exception e) { ???????????e.printStackTrace(); ???????} ???????// 去显示上传的文件 ???????request.setAttribute("pics", piclist); ???????request.getRequestDispatcher("index.jsp").forward(request, response); ???}}