Servlet教程____一个简单的Servlet(基于web.xml配置servelt)

1.定义页面和表单

2.定义servlet和业务流程

package com.test.servlet;import java.io.IOException;import java.util.Enumeration;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * @author Administrator * 测试实体类 */public class TestServlet extends HttpServlet{/** * SERID */private static final long serialVersionUID = 1L;@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {doPost(req, resp);System.out.println("get请求:"+req.getMethod());}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {/** * 使用request.parmeter获取页面的请求参数 */String username=req.getParameter("username");String userpwd=req.getParameter("userpwd");System.out.println("__________获取页面请求参数 : 用户名:"+username+":密码:"+userpwd);/** * 使用Enumreations获取 */Enumeration<String> enumeration=req.getParameterNames();while(enumeration.hasMoreElements()){String params=enumeration.nextElement();String[] paramValues = req.getParameterValues(params); for (int i = 0; i < paramValues.length; i++) {System.out.println(params+"的值为:"+paramValues[i]);}}if("admin".equals(username)){req.setAttribute("user", username);req.getRequestDispatcher("main.jsp").forward(req,resp);}}}

3.配置web.xml相关servlet信息

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">  <display-name>zservlet001</display-name>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list>  <!-- 测试servlet开始    -->  <!-- servlet配置 -->  <servlet>  <servlet-name>TestServlet</servlet-name>  <servlet-class>com.test.servlet.TestServlet</servlet-class>  </servlet>  <!-- servlet映射配置 -->  <servlet-mapping>  <servlet-name>TestServlet</servlet-name>  <url-pattern>/TestServlet</url-pattern>  </servlet-mapping><!-- 测试servlet结束  -->    </web-app>

4.运行结果