获取表单对象的值

来源：互联网发布：淘宝直播小二钉钉群编辑：程序博客网时间：2024/05/18 02:34

工程名：ServletStudy
表单文件：login.jsp
Servlet文件：LoginServlet.java
配置文件：web.xml
下面对是这几个文件的代码：
login.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>My JSP 'login.jsp' starting page</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>   <form action="/ServletStudy/LoginServlet">      userName: <input name="userName" type="text"/><br/>      password:  <input name="password" type="password"/><br/>      <input type="submit" value="submit"/>     <input type="reset" value="reset"/>   </form>  </body></html>

LoginServlet.java

package com;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@SuppressWarnings("serial")public class LoginServlet extends HttpServlet{   protected void doGet(HttpServletRequest req,HttpServletResponse resp)      throws ServletException, IOException      {        String username = req.getParameter("userName");        String password = req.getParameter("password");        resp.setContentType("text/html");        PrintWriter out = resp.getWriter();        out.println("<html><head><title>Login Result</title></head");        out.println("<body> username:"+username+"<br>");        out.println("password:"+password+"<br></body></html>");        out.flush();      }}

web.xml

在二级标签中添加以下代码：

<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>LoginServlet</servlet-name>    <servlet-class>com.LoginServlet</servlet-class>  </servlet><servlet-mapping>    <servlet-name>LoginServlet</servlet-name>    <url-pattern>/LoginServlet</url-pattern>  </servlet-mapping>

说明：

1.<form>标签中的action值为web.xml中的<url-pattern></url-pattern>中的值。再加上Servlet类名，如这里的是

/ServletStudy/LoginServlet

提交的方式默认为get方式，本例中即是以get方式提交的，这里没有对中文问题进行处理。但建议一般使用post方式提交表单。

2. String username =req.getParameter("userName");

这里的参数值“userName”要与<inputname="userName"type="text"/>中的name属性值相同

下面是使用doPost提交方式，关键部分代码为：

protected void doPost(HttpServletRequest req,HttpServletResponse resp)   throws ServletException, IOException   {      req.setCharacterEncoding("utf-8");      String username = req.getParameter("userName");      String password = req.getParameter("password");      resp.setContentType("text/html");      resp.setCharacterEncoding("utf-8"); //设置返回给客户端的文本格式，可解决文字编码格式不统一的问题      PrintWriter out = resp.getWriter();         out.println("<html><head><title>Login Result</title></head");      out.println("<body> username:"+username+"<br>");       out.println("password:"+password+"<br></body></html>");      out.flush();   }

若使用doPost方式响应客户，则要将<form>表单中的method的值改为post。

0 0