[Android] Retrofit2 GET, POST 로 API 호출해서 JSON 데이터 받아오기

build.grade (Module)

    dependencies {

        implementation 'com.squareup.retrofit2:retrofit:2.6.0'
        implementation 'com.squareup.retrofit2.converter-gson:2.6.0'

    }

AndroidManifest.xml

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

    <application
           ...
           android:networkSecurityConfig="@xml/network_security_config"
           ...>

res/xml/network_security_config

  <?xml version="1.0" encoding="utf-8"?>
    <network-security-config>
        <base-config cleartextTrafficPermitted="true"></base-config>
    </network-security-config>

Result.java

    public class Result {

        private String code;
        private String message;

        public String getCode() {
            return code;
        }

        public void setCode(String code) {
            this.code = code;
        }

        public String getMessage() {
            return message;
        }

        public void setCode(String message) {
            this.message = message;
        }

    }

RetrofitService.java

    public interface RetrofitService {

        @GET("/api/getdata")
        Call<Result> getData(@Query("authKey") String authKey, @Query("id") String id);

        @FormUrlEncoded
        @POST("/api/getdata")
        Call<Result> postData(@FieldMap HashMap<String, Object> param);

    }

API 호출 시, 반환되는 JSON

    {
        "code" : "SUCCESS",
        "message" : "정상적으로 조회되었습니다."
    }

MainActivity.java

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

        ...

    Retrofit retrofit = new Retrofit.Builder()
              .baseUrl("http://localhost:8080")
              .addConverterFactory(GsonConverterFactory.create())
              .build();

    Result result = retrofit.create(Result.class);

    // GET
    result.getData("12345", "1").enqueue(new Callback<Result>() {

        @Override
        public void onResponse(@NonNull Call<Result> call, @NonNull Response<Result> response) {

            if(response.isSuccessful()) {  // 조회성공
                Result data = response.body();
                Log.d("code ", data.getCode();
                Log.d("message ", data.getMessage();
            }
        }

        @Override
        public void onFailure(Call<Result> call, Throwable t) {
            t.printStackTrace();
        }

    });

    // POST
    HashMap<String, Object> param = new HashMap<String, Object>();
    param.put("authKey", "12345");
    param.put("id", "1");

    result.postData(param).enqueue(new Callback<Result>() {

        @Override
        public void onResponse(@NonNull Call<Result> call, @NonNull Response<Result> response) {

            if(response.isSuccessful()) {  // 조회성공
                Result data = response.body();
                Log.d("code ", data.getCode();
                Log.d("message ", data.getMessage();
            }
        }

        @Override
        public void onFailure(Call<Result> call, Throwable t) {
            t.printStackTrace();
        }
    });

...

    }

 

 

출처 : https://roadrunner.tistory.com/648