[MVC] Servlet 실습 / 터미널에서 http 로그 찍는법

package hello.servlet;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;

@ServletComponentScan //서블릿 직접등록후 사용하겠음.
@SpringBootApplication
public class ServeltApplication {

    public static void main(String[] args) {
       SpringApplication.run(ServeltApplication.class, args);
    }

}

package hello.servlet.hello.basic;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(name="helloServlet", urlPatterns = "/hello") //hello url로 들어오는 요청 처리
public class HelloServlet extends HttpServlet {

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.service(req, resp);
        System.out.println("HelloServlet.service");
        System.out.println("req = " + req);
        System.out.println("resp = " + resp);

        String username = req.getParameter("username");
        System.out.println("username = " + username);
    }
}

url 입력

http://localhost:8080/hello?username=kim

결과

 

* 응답도 찍어보기

package hello.servlet.hello.basic;

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(name="helloServlet", urlPatterns = "/hello") //hello url로 들어오는 요청 처리
public class HelloServlet extends HttpServlet {

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.service(req, resp);
        System.out.println("HelloServlet.service");
        System.out.println("req = " + req);
        System.out.println("resp = " + resp);

        String username = req.getParameter("username");
        System.out.println("username = " + username);

        resp.setContentType("text/plain"); //응답으로 문자를 보낼거임
        resp.setCharacterEncoding("utf-8");
        resp.getWriter().write("hello " + username);
    }
}

결과

개발자도구로 http msg 관찰

 

* servlet이 http 요청 파싱, 응답자동생성등 다해준다. (다 해줬잖아?)

 

* 터미널에서 http 로그 찍는법

 

 

* welcome html 추가

결과

main > wepapp 경로에 index.html은 별도 설정없이 , spring이 자동 홈페이지로 설정한다.