json Data 활용

JSON 작업파일(JSONTest)

GitHub - chaSunil/FirstProject: 1차 프로젝트

 

 

제이슨 타입으로 데이터 출력하기

json-20240303.jar

0.07MB

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

{
	"size": 3,
	"list":[
		{"name":"홍길동","age":31,"tel":"010-111-1234"},
		{"name":"이길동","age":32,"tel":"010-222-1234"},
		{"name":"삼길동","age":33,"tel":"010-333-1234"}
		]
}

 

 

 

 

 

Servlet 만들기 (json을 String, int, Array로 받기)

package action;

import jakarta.servlet.RequestDispatcher;
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;

import org.json.JSONArray;
import org.json.JSONObject;

/**
 * Servlet implementation class JSONParseAction
 */
@WebServlet("/json_parse.do")
public class JSONParseAction extends HttpServlet {
	private static final long serialVersionUID = 1L;

	/**
	 * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// {"name":"일길동","age":30,"hobby":["독서","낚시"]};
		String json_str = "";
		JSONObject json = new JSONObject("{\"name\":\"일길동\",\"age\":30,\"hobby\":[\"독서\",\"낚시\"]};");
		
		String name = json.getString("name");
		int age = json.getInt("age");
		
		// JSON 배열 읽어오기
		JSONArray hobbyArray = json.getJSONArray("hobby");
		for(int i=0; i<hobbyArray.length(); i++) { // i=0, i=1
			String hobby = hobbyArray.getString(i);
		}
		
		System.out.printf("이름:%s 나이:%d 취미:%s\n", name, age, hobbyArray);

		// Dispatcher형식으로 호출
		String forward_page = "result_json.jsp";
		RequestDispatcher disp = request.getRequestDispatcher(forward_page);
		disp.forward(request, response);

	}

}

 

 

 

http안에 작성한 json 데이터를 url 주소를 받아와서 값을 가져오기

package action;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class JSONParseAction
 */
@WebServlet("/json_parse.do")
public class JSONParseAction extends HttpServlet {
	private static final long serialVersionUID = 1L;

	/**
	 * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		List<PersonVo> p_list = new ArrayList<PersonVo>();
		
		try {
			String str_url = "http://localhost:8080/2024_0709_JSONTest/person.jsp";
			URL url = new URL(str_url);
			// 이용하는 이유: 요청시 헤더 정보 전달(인증키)
			URLConnection urlConn = url.openConnection();
			
			InputStream is = urlConn.getInputStream();
			
			// line 단위로 읽어온다.
			BufferedReader br = new BufferedReader(new InputStreamReader(is, "utf-8"));
			
			StringBuilder sb = new StringBuilder();
			
			while(true) {
				String data = br.readLine(); // line 단위로 읽어온다.
				if(data==null) break;
				
				sb.append(data+"\n");
			}
			
			// System.out.println(sb.toString());
			// JSON Parsing
			JSONObject json = new JSONObject(sb.toString());
			int size = json.getInt("size");
			JSONArray personArray = json.getJSONArray("list");
			
			for(int i = 0; i<personArray.length(); i++) {
				JSONObject person = personArray.getJSONObject(i);
				// person = {"name":"홍길동","age":31,"tel":"010-111-1234"}
				String name = person.getString("name");
				int age = person.getInt("age");
				String tel = person.getString("tel");
				
				PersonVo vo = new PersonVo(name, age, tel);
				p_list.add(vo);
			}
			
			
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		// request binding
		request.setAttribute("p_list", p_list);

		// Dispatcher형식으로 호출
		String forward_page = "result_json.jsp";
		RequestDispatcher disp = request.getRequestDispatcher(forward_page);
		disp.forward(request, response);

	}

}

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

<table border="1" align="center">
	<tr>
		<th>이름</th>
		<th>나이</th>
		<th>전화번호</th>
	</tr>
	<!-- for(PersonVo vo : p_list) -->
	<c:forEach var="vo" items="${ requestScope.p_list }">
	<tr>
		<td>${ vo.name }</td>
		<td>${ vo.age }</td>
		<td>${ vo.tel }</td>
	</tr>
	</c:forEach>
</table>

</body>
</html>