enctype=“multipart/form-data”，Servlet获取参数
原创 2017年03月21日 18:46:44 标签：enctype /servlet文件上传 2094
HTML表单enctype属性是设置表单传输的MIME编码，共有三个值可选：①application/x-www-form-urlencoded (默认值，不能用于文件上传)②multipart/form-data (指定传输数据为二进制类型，比如图片、mp3、文件)③text/plain (纯文本传输,发送邮件，接收时不会出现乱码)UploadDemo.jsp
[html] view plain copy
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html> <head> <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"> </head> <body> <form action="${pageContext.request.contextPath}/servlet/ServletUploadDemo" method="post" enctype="multipart/form-data"> name:<input type="text" name="name"/><br/> age:<input type="text" name="age"><br/> file:<input type="file" name="file"/><br/> <input type="submit" value="上传"/> </form> </body>
</html> ServletUploadDemo.java[java] view plain copy
package com.text; import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part; //Servlet3.0+可以不用web.xml文件，改用注解方式映射。
//文件上传已经是Servlet3.0+必有的。
//Part:接口。代表表单中的每一项。相当于FileItem
@WebServlet("/servlet/ServletUploadDemo") @MultipartConfig//**加上这个注解，反射该Servlet时才知道处理的是文件上传 public class ServletUploadDemo extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //普通参数还可以照常取出（@MultipartConfig不能忘） String name = request.getParameter("name"); String age = request.getParameter("age"); //特殊参数用part取 Part part = request.getPart("file");
// System.out.println(name+"--"+age);
// System.out.println(part); //获取文件名 String contentDisposition = part.getHeader("Content-Disposition"); System.out.println(contentDisposition);// form-data; name="file"; filename="User.sql" int filenameIndex = contentDisposition.indexOf("filename="); String filename = contentDisposition.substring(filenameIndex+10, contentDisposition.length()-1); part.write(getServletContext().getRealPath("/files")+"/"+filename); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
