[Servlet] HTTP 응답 데이터 - API JSON

목표 : Servlet으로 HTTP 응답데이터를 JSON으로 뿌리는 방법

 

package hello.servlet.basic.response;

import com.fasterxml.jackson.databind.ObjectMapper;
import hello.servlet.basic.HelloData;

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(name = "responseJsonServlet", urlPatterns = "/response-json")
public class ResponseJsonServlet extends HttpServlet {

    //객체를 JSON으로 응답

    ObjectMapper objectMapper = new ObjectMapper();

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //Content-Type: application/json
        response.setContentType("application/json");

        HelloData helloData = new HelloData();
        helloData.setUsername("kim");
        helloData.setAge(20);

        //객체를 JSON으로 변경
        String result = objectMapper.writeValueAsString(helloData);

        response.getWriter().write(result); //JSON으로 출력
    }
}

 

테스트 결과