tamcat学习2之使用Maven新建webapp,并从HelloServlet中读取变量值

来源：互联网发布：大数据通用解决方案编辑：程序博客网时间：2024/06/06 04:54

1.相对于前一篇，需要新建HelloServlet.java：

package org.ms.bop.server;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class HelloServlet */public class HelloServlet extends HttpServlet {private static final long serialVersionUID = 1L;    /**     * Default constructor.      */    public HelloServlet() {        // TODO Auto-generated constructor stub    }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setAttribute("hello","world1");request.getRequestDispatcher("hello.jsp").forward(request, response);}/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stub}}

2.新建hello.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%>    <%@ page isELIgnored="false" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><h1>hello:${hello }</h1></body></html>

3.配置web.xml:

<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" ><web-app><display-name>Archetype Created Web Application</display-name><servlet><servlet-name>HelloServlet</servlet-name><servlet-class>org.ms.bop.server.HelloServlet</servlet-class></servlet><servlet-mapping><servlet-name>HelloServlet</servlet-name><url-pattern>/hello.do</url-pattern></servlet-mapping></web-app>

4.发布访问：

http://127.0.0.1:8080/WebTest/hello.do

返回的是：

hello:world1

5.问题总结：

如果jsp中不加：

<%@ page isELIgnored="false" %>

会无法识别el，显示的是：

hello:${hello }

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