Servlet配置(IDEA)

方法一：
WEB-INF下配置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>
  <!--注册Servlet-->
  <servlet>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>com.sonny.servlet.LoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/LoginServlet</url-pattern>
  </servlet-mapping>
</web-app>

方法二：直接在servlet类前添加@WebServlet("/HelloServlet")注释

package com.sonny.servlet;

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;
import java.io.PrintWriter;

@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
    //由于get或者post只是实现请求的不同方式，可以相互调用，业务逻辑都一样
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        PrintWriter writer = resp.getWriter();//响应流
        writer.println("hello Servlet");
        System.out.println("123");
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    }
}

注：直接在webapp根目录下创建jsp，否则Servlet不生效