Servlet
文章目录
文章目录
- 文章目录
- 一、Servlet快速入门
- 二、Servlet的生命周期
- 三、servlet方法
- 四、servlet体系结构
- 五、servlet urlPattern配置
- 六、XML配置方式编写servlet
一、Servlet快速入门
案例:
//servlet依赖坐标<dependencies> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> </dependencies>package com.study.web;import javax.servlet.*;import javax.servlet.annotation.WebServlet;import java.io.IOException;@WebServlet("/demo1")public class ServletDemo1 implements Servlet { @Override public void init(ServletConfig servletConfig) throws ServletException { System.out.println("Hello!"); } @Override public ServletConfig getServletConfig() { return null; } @Override public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException { } @Override public String getServletInfo() { return null; } @Override public void destroy() { }}
在控制台会打印Hello!。
二、Servlet的生命周期
案例:
package com.study.web;import javax.servlet.*;import javax.servlet.annotation.WebServlet;import java.io.IOException;@WebServlet("/demo2")public class ServletDemo2 implements Servlet { //第一次访问servlet的时候调用,该方法只调用一次。 @Override public void init(ServletConfig servletConfig) throws ServletException { System.out.println("init......."); } //每次访问Servlet时都会被调用 @Override public void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException { System.out.println("Hello Service"); } //释放内存或容器关闭时调用,只调用一次 @Override public void destroy() { System.out.println("destroy...."); } @Override public String getServletInfo() { return null; } @Override public ServletConfig getServletConfig() { return null; }}
三、servlet方法
四、servlet体系结构
案例:
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>Title</title></head><body><form action="http://localhost:8080/demo3" method="post"> <input name="username" type="text"><input type="submit" value="提交"></form></body></html>package com.study.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("/demo3")public class ServletDemo3 extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("doGet..."); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("doPost..."); }}
五、servlet urlPattern配置