珠海网站建设公司排名,wordpress怎么换语言,沈阳酒店企业网站制作公司,公司网站的具体的建设方案文章目录 简介一、快速入门二、Servlet 执行流程三、Servlet 生命周期四、Servlet 方法介绍五、Servlet 体系结构六、Servlet urlPattern配置七、XML 配置方式编写 Servlet 简介 一、快速入门 dependenciesdependencygroupIdjavax.servlet/groupId… 文章目录 简介一、快速入门二、Servlet 执行流程三、Servlet 生命周期四、Servlet 方法介绍五、Servlet 体系结构六、Servlet urlPattern配置七、XML 配置方式编写 Servlet 简介 一、快速入门 dependenciesdependencygroupIdjavax.servlet/groupIdartifactIdjavax.servlet-api/artifactIdversion3.1.0/versionscopeprovided/scope/dependency/dependenciespackage com.itheima.web;import javax.jws.WebService;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;WebServlet(/demo1)
public class MyHttpServlet implements Servlet {Overridepublic void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {System.out.println(Hello World);}Overridepublic void init(ServletConfig config) throws ServletException {}Overridepublic ServletConfig getServletConfig() {return null;}protected void doPost(ServletRequest req, ServletResponse res) {}protected void doGet(ServletRequest req, ServletResponse res) {}Overridepublic String getServletInfo() {return null;}Overridepublic void destroy() {}
}
二、Servlet 执行流程 三、Servlet 生命周期 package com.itheima.web;import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import java.io.IOException;/*** Servlet 生命周期方法*/
WebServlet(urlPatterns/demo2,loadOnStartup 1)
public class ServletDemo2 implements Servlet {/*** 初始化方法* 1. 调用时机默认情况下Servlet被第一次访问时调用* * loadOnStartup:* 2. 调用次数1次* param config* throws ServletException*/Overridepublic void init(ServletConfig config) throws ServletException {System.out.println(init...);}/*** 提供服务* 1. 调用时机每一次Servlet被访问时调用* 2. 调用次数多次*** param req* param res* throws ServletException* throws IOException*/Overridepublic void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {System.out.println(servlet hello world~);}/*** 销毁方法* 1. 调用时机内存释放或者服务器关闭的时候Servlet对象会被销毁调用* 2. 调用次数1次*/Overridepublic void destroy() {System.out.println(destroy...);}Overridepublic String getServletInfo() {return null;}Overridepublic ServletConfig getServletConfig() {return null;}
}
四、Servlet 方法介绍 package com.itheima.web;import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import java.io.IOException;/*** Servlet 方法介绍*/
WebServlet(urlPatterns/demo3,loadOnStartup 1)
public class ServletDemo3 implements Servlet {private ServletConfig config;/*** 初始化方法* 1. 调用时机默认情况下Servlet被第一次访问时调用* * loadOnStartup:* 2. 调用次数1次* param config* throws ServletException*/Overridepublic void init(ServletConfig config) throws ServletException {this.config config;System.out.println(init...);}Overridepublic ServletConfig getServletConfig() {return config;}/*** 提供服务* 1. 调用时机每一次Servlet被访问时调用* 2. 调用次数多次*** param req* param res* throws ServletException* throws IOException*/Overridepublic void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {System.out.println(servlet hello world~);}/*** 销毁方法* 1. 调用时机内存释放或者服务器关闭的时候Servlet对象会被销毁调用* 2. 调用次数1次*/Overridepublic void destroy() {System.out.println(destroy...);}Overridepublic String getServletInfo() {return ;}}
五、Servlet 体系结构 package com.itheima.web;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;WebServlet(/demo4)
public class ServletDemo4 extends HttpServlet {Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println(get...);}Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {System.out.println(post...);}
}
要调用dopost方法时要在webapp中写一个html方便查看
!DOCTYPE html
html langen
headmeta charsetUTF-8titleTitle/title
/head
bodyform action/web-demo/demo5 methodpostinput nameusernameinput typesubmit
/form
/body
/htmlpackage com.itheima.web;import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;public class MyHttpServlet implements Servlet {Overridepublic void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {// 根据请求方式的不同进行分别的处理HttpServletRequest request (HttpServletRequest) req;//1. 获取请求方式String method request.getMethod();//2. 判断if(GET.equals(method)){// get方式的处理逻辑doGet(req,res);}else if(POST.equals(method)){// post方式的处理逻辑doPost(req,res);}}Overridepublic void init(ServletConfig config) throws ServletException {}Overridepublic ServletConfig getServletConfig() {return null;}protected void doPost(ServletRequest req, ServletResponse res) {}protected void doGet(ServletRequest req, ServletResponse res) {}Overridepublic String getServletInfo() {return null;}Overridepublic void destroy() {}
}
继承HttpServlet
package com.itheima.web;import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;WebServlet(/demo5)
public class ServletDemo5 extends MyHttpServlet {Overrideprotected void doGet(ServletRequest req, ServletResponse res) {System.out.println(get。。。。);}Overrideprotected void doPost(ServletRequest req, ServletResponse res) {System.out.println(post。。。。);}
}
六、Servlet urlPattern配置 七、XML 配置方式编写 Servlet ?xml version1.0 encodingUTF-8?
web-app xmlnshttp://xmlns.jcp.org/xml/ns/javaeexmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexsi:schemaLocationhttp://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsdversion4.0!--Servlet 全类名--servletservlet-namedemo13/servlet-nameservlet-classcom.itheima.web.ServletDemo13/servlet-class/servlet!--Servlet 访问路径--servlet-mappingservlet-namedemo13/servlet-nameurl-pattern/demo13/url-pattern/servlet-mapping
/web-app
