java学习笔记 (7) —— 实现简单的上传处理
1、下载apache 的 commons-fileupload.jar 包及 commons-io.jar
2、引入到lib 文件夹下
3、新建uploadApache.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> </head> <body> <!-- 20 min!!! --> <form action="/testStruts2/UploadServlet" method="post" enctype="multipart/form-data"> username: <input type="text" name="username"/> password: <input type="password" name="password" /> file1: <input type="file" name="file1" /><br> file2: <input type="file" name="file2" /><br> <input type="submit" value="submit"> </form> </body> </html>
4、新建resultApache.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> </head> <body> username : ${requestScope.username} password: ${requestScope.password } file1:${requestScope.file1 } file2:${requestScope.file2 } </body> </html>
5、修改web.xml文件
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet> <servlet-name>UploadServlet</servlet-name> <servlet-class>com.test.servlet.UploadServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>UploadServlet</servlet-name> <url-pattern>/UploadServlet</url-pattern> </servlet-mapping> </web-app>
5、新建UploadServlet.java
package com.test.servlet; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; 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 { private static final long serialVersionUID = 1L; @SuppressWarnings("deprecation") public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //定义一个工厂类 DiskFileItemFactory factory = new DiskFileItemFactory(); //获取当前站点目录下upload的路径 String path = request.getRealPath("/upload"); //设置文件暂存路径 factory.setRepository(new File(path)); //设置允许放在内存中的最大空间 factory.setSizeThreshold(1024*1024); ServletFileUpload upload = new ServletFileUpload(factory); try{ //uploadApache.jsp 有多个文本框，传入的是一组文件，因此通过LIST 处理 List<FileItem> list = upload.parseRequest(request); //循环 for (FileItem item : list) { //如果是一般的字段，直接放入request中 if(item.isFormField()){ String name = item.getFieldName(); String value = item.getString("gbk"); request.setAttribute(name, value); //如果是文件类型的字段，则需要进行处理 }else { String name = item.getFieldName(); //file 类型表单 String value = item.getName(); int start = value.lastIndexOf("\\"); //截取最后的文件名 String fileName = value.substring(start+1); //在request中保存内容，用于前台获取 request.setAttribute(name, fileName); //一句话也可以概括 //item.write(new File(path,fileName)); //定义输出流，输出路径及文件名称 OutputStream os = new FileOutputStream(new File(path,fileName)); //定义输入流，并获取单个的输入流内容 InputStream is = item.getInputStream(); //定义字节流以获取输入流内容 byte[] buffer = new byte[400]; int length = 0; while ((length = is.read(buffer)) > 0) { os.write(buffer,0,length); } os.close(); is.close(); } } request.getRequestDispatcher("upload/resultApache.jsp"); }catch (Exception e) { e.printStackTrace(); } } }
