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코리아 IT아카데미/android

13일차 | http 통신 ? 못 알아 들겠음

by Sharon kim 2022. 3. 3.

Google 에서 다운로드 Talend API Tester  -> 포스트맨 대신 사용

가상의 json 파일 :
https://jsonplaceholder.typicode.com/

https://github.com/google/gson
implementation 'com.google.code.gson:gson:2.9.0'

코드 추가

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

MainActivity.java

package com.example.myhttpconnection;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

import com.example.myhttpconnection.models.Person;
import com.example.myhttpconnection.models.User;
import com.example.myhttpconnection.models.response.ResTodo;
import com.example.myhttpconnection.service.UserService;
import com.example.myhttpconnection.utils.HttpClient;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

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

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.reflect.Array;
import java.lang.reflect.Type;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;

public class MainActivity extends AppCompatActivity {

    private static String TAG = "TAG";
    ArrayList<Person> personArrayList;
    ArrayList<ResTodo> todos;
    TextView textView;
    HttpClient httpClient;
    User user;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        UserService userService = new UserService();
        user = userService.read("10");

    }

    private void requestTodos() {
        new Thread(() -> {
            try {
                todos = httpClient.todos("/todos");
                Log.d(TAG, "todos : " + todos.toString());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }).start();

    }

    private void savePost() {
        new Thread(() -> {
            try {
                httpClient.posts("/posts");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }).start();
    }

    /**
     * JSON Object
     * JSON Array
     */
    private void testCodeForJson() {
        // 1. 하나의 jsonObject 만들기
        // 2. JSON Array 만들기

        // JSON Object 형태로 만들어 주는 녀석
        // { key : value }
        JSONObject jsonObject = new JSONObject();
        JSONArray jsonArray = new JSONArray();

        try {
            jsonObject.put("이름", "홍길동");
            jsonObject.put("나이", 30);
            jsonObject.put("직업", "개발자");
            jsonObject.put("취미", "게임");
            jsonObject.put("결혼여부", false);

            jsonArray.put(jsonObject);
            jsonArray.put(jsonObject);
            jsonArray.put(jsonObject);
//            Log.d(TAG, jsonArray.toString());

            // 사용해 보기
            // 1. JSON OBJECT 파싱 하기
//            Log.d(TAG, jsonObject.toString());
//            Person person = new Gson().fromJson(jsonObject.toString(), Person.class);
//            Log.d(TAG, person.get이름());
//            Log.d(TAG, person.get나이() + "");

            // 2. JSON Array 파싱 하기 !
//            Person[] people = new Gson().fromJson(jsonArray.toString(), Person[].class);
//            Log.d(TAG, Arrays.toString(people));

            // 3. ArrayList 로 파싱하는 방법
            Type listType = new TypeToken<ArrayList<Person>>(){}.getType();
            personArrayList = new Gson().fromJson(jsonArray.toString(), listType);
            Log.d(TAG, personArrayList.get(0).toString());

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

    /**
     * 자바, 안드로이에서 통신프로토을을 활용해서
     * 서버측에 데이터를 요청해서 응답 (HTTP)
     */
    private void httpConnectionTestCode() {

        // 익명클래스로 쓰래드 만들기
        new Thread(new Runnable() {
            @Override
            public void run() {
                // 1. 준비물 URL 객체 필요
                String baseUrl = "https://jsonplaceholder.typicode.com/";
                String endPoint = "todos/1";
                try {
                    // Http Request Message 생성 (시작줄 + http header)
                    URL url = new URL(baseUrl + endPoint);
                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                    conn.setRequestMethod("GET"); // GET, POST, PUT, DELETE

                    // 결과값 받기
                    // 1. 응답 코드 받기
                    // 상태코드 1xx(진행중), 2xx(성공), 3xx(리다렉트), 4xx(실패: 잘못된요청), 500(연산오류)
                    // GET 성공 ---> 200 호출
                    // POST 성공 ---> 201 호출
                    Log.d("TAG", "상태코드 받아 보기 " + conn.getResponseCode());

                    // 응답 바디 데이터 받아 보기
                    if(conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                        BufferedReader reader = new BufferedReader(
                                new InputStreamReader(conn.getInputStream())
                        );

                        // Dto
                        ResTodo todo = new Gson().fromJson(reader, ResTodo.class);
                        Log.d(TAG, todo.toString()); // -> 주소값 :: --> 오버라이드 처리
                        Log.d(TAG, todo.getTitle());
                        Log.d(TAG, todo.getBody());

//                        String line = null;
//                        StringBuffer sb = new StringBuffer();
//                        while ( (line = reader.readLine()) != null  ) {
//                            sb.append(line +"\n");
//                        }
//                        Log.d(TAG, sb.toString());
//                        String responseResult = sb.toString();
//                        String key = responseResult.substring(3, 10);
//                        String value = responseResult.substring(11, 14);
//                        Log.d(TAG, "key : " + key);
//                        Log.d(TAG, "value : " + value);
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
        }).start();
    }
}

 

SubActivity.java

package com.example.myhttpconnection;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

import com.example.myhttpconnection.service.TodoService;

public class SubActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sub);

        TodoService todoService = new TodoService();
        //Todo todo = todoService.read();
        // 화면 만드는 부분 집중
    }
}

 

models.pac>

    request.pac>

        ReqPost.java

package com.example.myhttpconnection.models.request;

public class ReqPost {

    private String title;
    private String body;
    private int userId;

    public ReqPost(String title, String body, int userId) {
        this.title = title;
        this.body = body;
        this.userId = userId;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }
}

 

models.pac>

    response.pac>

        r-1. ResPost.java

        r-2. ResTodo.java

 

r-1.

package com.example.myhttpconnection.models.response;

public class ResPost {
    private int id;
    private String title;
    private String body;
    private int userId;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }


    @Override
    public String toString() {
        return "ResPost{" +
                "id=" + id +
                ", title='" + title + '\'' +
                ", body='" + body + '\'' +
                ", userId=" + userId +
                '}';
    }
}

r-2.

package com.example.myhttpconnection.models.response;

public class ResTodo {
    private int userId;
    private int id;
    private String title;
    private String body;

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    @Override
    public String toString() {
        return "ResTodo{" +
                "userId=" + userId +
                ", id=" + id +
                ", title='" + title + '\'' +
                ", body='" + body + '\'' +
                '}';
    }
}

 

models.pac>

   m-1. Person.java

   m-2. User.java

 

m-1.

package com.example.myhttpconnection.models;

public class Person {
    String 이름;
    int 나이;
    String 직업;
    String 취미;
    Boolean 결혼여부;

    public String get이름() {
        return 이름;
    }

    public void set이름(String 이름) {
        this.이름 = 이름;
    }

    public int get나이() {
        return 나이;
    }

    public void set나이(int 나이) {
        this.나이 = 나이;
    }

    public String get직업() {
        return 직업;
    }

    public void set직업(String 직업) {
        this.직업 = 직업;
    }

    public String get취미() {
        return 취미;
    }

    public void set취미(String 취미) {
        this.취미 = 취미;
    }

    public Boolean get결혼여부() {
        return 결혼여부;
    }

    public void set결혼여부(Boolean 결혼여부) {
        this.결혼여부 = 결혼여부;
    }

    @Override
    public String toString() {
        return "Person{" +
                "이름='" + 이름 + '\'' +
                ", 나이=" + 나이 +
                ", 직업='" + 직업 + '\'' +
                ", 취미='" + 취미 + '\'' +
                ", 결혼여부=" + 결혼여부 +
                '}';
    }
}

m-2. 

package com.example.myhttpconnection.models;


public class User {

    private int id;
    private String name;
    private String username;
    private String email;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", username='" + username + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
}

 

repository.pac>

    re-1. TodoRepository.interface

    re-2. UserRepository.interface

 

re-1.

package com.example.myhttpconnection.repository;

public interface TodoRepository {

    void create();
    void read();
    void update();
    void delete();
}

re-2.

package com.example.myhttpconnection.repository;

import com.example.myhttpconnection.models.User;

public interface UserRepository {

    // C R U D
    void create(String id, String pw);
    User read(String id);
    void update(User user);
    void delete(String id);

}

 

service>

   s-1. TodoService.java

   s-2. UserService.java

 

s-1. 

package com.example.myhttpconnection.service;

import com.example.myhttpconnection.repository.TodoRepository;

public class TodoService implements TodoRepository {

    @Override
    public void create() {

    }

    @Override
    public void read() {

    }

    @Override
    public void update() {

    }

    @Override
    public void delete() {

    }
}

s-2. 

package com.example.myhttpconnection.service;

import android.util.Log;

import com.example.myhttpconnection.models.User;
import com.example.myhttpconnection.repository.UserRepository;
import com.example.myhttpconnection.utils.HttpClient2;
import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;

public class UserService implements UserRepository {

    private User user;

    @Override
    public void create(String id, String pw) {

    }

    @Override
    public User read(String id) {
        new Thread(() -> {
           HttpURLConnection conn = HttpClient2.getInstance().getConnection("/users/" + id, HttpClient2.GET);
            try {
                if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                    BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
                    user = new Gson().fromJson(reader, User.class);
                    Log.d("TAG", user.toString());

                } else {
                    Log.d("TAG", "연결실패 또는 오류");
                    Log.d("TAG", "status code : " + conn.getResponseCode());
                }
            } catch (IOException e) {
                e.printStackTrace();
            }

            try {
                conn.connect();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }).start();

        return user;
    }

    @Override
    public void update(User user) {

    }

    @Override
    public void delete(String id) {

    }
}

 

utils>

  u-1. HttpClient.java

  u-2. HttpClient2.java

 

u-1.

package com.example.myhttpconnection.utils;

import android.util.Log;

import com.example.myhttpconnection.models.request.ReqPost;
import com.example.myhttpconnection.models.response.ResPost;
import com.example.myhttpconnection.models.response.ResTodo;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.lang.reflect.Type;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;

public class HttpClient {

    private static HttpClient httpClient;

    private static final String baseURL = "https://jsonplaceholder.typicode.com";
    private HttpURLConnection conn;
    public final static String GET = "GET";
    public final static String POST = "POST";
    public final static String PUT = "PUT";
    public final static String DELETE = "DELETE";

    // 싱글톤 패턴
    private HttpClient() {
    }

    public static HttpClient getInstance() {
        if (httpClient == null) {
            httpClient = new HttpClient();
        }
        return httpClient;
    }

    // todos
    public ArrayList<ResTodo> todos(String path) throws Exception {
        ArrayList<ResTodo> resTodos = new ArrayList<>();
        URL url = new URL(baseURL + path);
        conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod(GET);
        if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            Type listType = new TypeToken<ArrayList<ResTodo>>() {
            }.getType();
            resTodos = new Gson().fromJson(reader, listType);
        }
        conn.disconnect();
        return resTodos;
    }

    public void posts(String path) throws Exception {

        URL url = new URL(baseURL + path);
        conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod(POST);
        conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
        conn.setDoInput(true);
        conn.setDoInput(true);
        conn.setConnectTimeout(3000);

        OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
        ReqPost reqPost = new ReqPost("하이", "응답확인", 1);
        String jsonObject = new Gson().toJson(reqPost);
        writer.write(jsonObject);
        writer.close();

        BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        ResPost resPost = new Gson().fromJson(reader, ResPost.class);
        Log.d("TAG", resPost.toString());
        Log.d("TAG", conn.getResponseCode() + "");
        conn.disconnect();
    }

}

u-2.

package com.example.myhttpconnection.utils;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class HttpClient2 {

    private static HttpClient2 httpClient2;

    private static final String baseURL = "https://jsonplaceholder.typicode.com";
    private HttpURLConnection conn;
    public final static String GET = "GET";
    public final static String POST = "POST";
    public final static String PUT = "PUT";
    public final static String DELETE = "DELETE";

    private HttpClient2() {
    }

    public static HttpClient2 getInstance() {
        if (httpClient2 == null) {
            httpClient2 = new HttpClient2();
        }
        return httpClient2;
    }

    public HttpURLConnection getConnection(String endPoint, String method) {
        try {
            URL url = new URL(baseURL + endPoint);
            conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod(method);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

 

 

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