Servlet实现图片文件上传

1.首先要导入以下两个jar包：

commons-fileupload-1.2.1.jar
commons-io-1.4.jar

2.jsp文件：index.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>文件上传</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>

         表单/带文件

         <br>

         <!--    application/x-www-form-urlencoded只有字符串的表单 -->

         <form action="${pageContext.request.contextPath}/UploadPictureServlet" method="post" enctype="multipart/form-data">

             文件名

             <input type="text" name="filename">

             <br />

             文件

             <input type="file" name="file">

             <br />

             <input type="submit" value="提交">

         </form>

     </body>

 </html>

3.Servlet文件：

  package com.pearl.util;

  1 import java.io.File;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.List;

 import java.util.UUID;

 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 UploadPictureServlet extends HttpServlet {

     public void destroy() {

         super.destroy();

     }

     public void doGet(HttpServletRequest request, HttpServletResponse response)

             throws ServletException, IOException {

         doPost(request, response);

     }

     public void doPost(HttpServletRequest request, HttpServletResponse response)

             throws ServletException, IOException {

         try {

             // ①　创建ServletFileUpload实例

             DiskFileItemFactory factory = new DiskFileItemFactory();

             String realPath = getServletContext().getRealPath("/");

             // // 【设置缓存目录】

             factory.setRepository(new File(realPath));

             ServletFileUpload upload = new ServletFileUpload(factory);

             // ②　创建DiskFileItemFactory

             // ③　解析request获取List<FileItem>

             // 【表单大小总和】

             upload.setSizeMax(1024 * 1024 * 60);

             // 【单个文件不得超过】

             upload.setFileSizeMax(1024 * 1024 * 20);

             // 【处理中文乱码】

             upload.setHeaderEncoding("UTF-8");

             if (upload.isMultipartContent(request)) {// 判断是否为带文件表单 <form

                 // enctype="multipart/form-data"

                 List<FileItem> list = upload.parseRequest(request);

                 for (FileItem item : list) {

                     // 文本或文件

                     if (item.isFormField()) {

                         // 文本字段

                         // 获取变量名

                         String key = item.getFieldName();// 表单字段的变量名

                         String value = item.getString("UTF-8");// 表单字段的输入值

                         System.out.println(key);

                         System.out.println(value);

                     } else {

                         // 文件

                         // 文件类型

                         // text/plain .txt

                         // image/png .png

                         // image/bmp .bmp

                         String contentType = item.getContentType();

                         // 文件名

                         String fileName = item.getName();// 表单的输入框值

                         // 变量名

                         String name = item.getFieldName();// 表单的变量名

                         // 文件 内容

                         String content = item.getString();

                         // 二进制文件

                         InputStream input = item.getInputStream();

                         System.out.println(contentType);

                         System.out.println(fileName);

                         System.out.println(name);

                         //System.out.println(content);

                         System.out.println(input);

                         // ①　服务端目录 (服务端真实路径)

                         String dir = getServletContext().getRealPath("/upload");

                         System.out.println(dir);

                         // ②　文件名冲突

                         if (fileName.contains("/")) {

                             fileName = fileName.substring(name.lastIndexOf("/") + 1);

                             System.out.println(fileName);

                         }

                         // (添加前缀 唯一字符串， 时间毫秒值 UUID随机产生全球唯的id)

                         String path = UUID.randomUUID().toString() + "#" + fileName;

                         // ③　写入File对象

                         File driSave = new File(dir);

                         if (!driSave.exists()) {

                             driSave.mkdir();

                         }

                         File saveFile = new File(dir, path);

                         if (!saveFile.exists()) {

                             saveFile.createNewFile();

                         }

                         System.out.println(saveFile.getAbsolutePath());

                         item.write(saveFile);

                         // 删除临时文件

                         item.delete();

                         input.close();

                     }

                 }

             } else {

                 System.out.println("表单不存在文件");

             }

             // ④　循环显示内容FileItem

         } catch (Exception e) {

             // TODO Auto-generated catch block

             e.printStackTrace();

         }

     }

     public void init() throws ServletException {

     }

 }

4.web.xml文件

 <?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>UploadPictureServlet</servlet-name>

     <servlet-class>com.pearl.util.UploadPictureServlet</servlet-class>

   </servlet>

   <servlet-mapping>

     <servlet-name>UploadPictureServlet</servlet-name>

     <url-pattern>/UploadPictureServlet</url-pattern>

   </servlet-mapping>

   <welcome-file-list>

     <welcome-file>index.jsp</welcome-file>

   </welcome-file-list>

 </web-app>

5.完成

巴特西

Servlet实现图片文件上传

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