Servlet生命周期

package com.gem.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;

/**
 * @author zhang
 * @date 2020/9/8 14:44
 */
@WebServlet("/hello")
public class HelloServlet extends HttpServlet {
    public HelloServlet(){
        System.out.println("这是构造方法");
    }

    @Override
    public void init() throws ServletException {
        super.init();
        System.out.println("初始化方法");
    }

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("这是服务方法");
    }

    @Override
    public void destroy() {
        System.out.println("这是销毁方法");
        super.destroy();
    }
}

@WebServlet(urlPatterns = "/hello",loadOnStartup = 1)

@WebServlet(urlPatterns = "/hello",initParams = {@WebInitParam(name = "username",value = "root"),@WebInitParam(name = "password",value = "root")})

ServletConfig config = getServletConfig();
String username = config.getInitParameter("username");
String password = config.getInitParameter("password");
System.out.println(username + "-------" + password);