[Java] Retrofit2

build.gradle (Module: app)

dependencies {
    // Retrofit2
    implementation 'com.squareup.retrofit2:retrofit:2.7.1'
    implementation 'com.squareup.retrofit2:converter-gson:2.7.1'
    implementation 'com.squareup.okhttp3:logging-interceptor:4.3.1'
}

 

 

 

 

 

 

 

 

AndroidManifast.xml

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

인터넷 권한 추가.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.jwsoft.javaproject">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

 

 

 

 

 

 

 

 

RetrofitAPI.java

package com.jwsoft.javaproject;

import com.google.gson.JsonObject;

import java.util.List;

import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Path;

public interface RetrofitAPI {
    @GET("/users/{user}/repos")
    Call<List<JsonObject>> getUserRepos(@Path("user") String userName);
}

 

 

 

 

 

 

 

 

MainActivity.java

package com.jwsoft.javaproject;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import com.google.gson.JsonObject;

import org.jetbrains.annotations.NotNull;

import java.util.List;

import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public class MainActivity extends AppCompatActivity {

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

        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() {
            @Override
            public void log(@NotNull String s) {
                Log.e("", s);
            }
        });

        interceptor.level(HttpLoggingInterceptor.Level.BODY);

        OkHttpClient client = new OkHttpClient.Builder()
            	.connectTimeout(5, TimeUnit.SECONDS)
                .readTimeout(5, TimeUnit.SECONDS)
                .writeTimeout(5, TimeUnit.SECONDS)
                .addInterceptor(interceptor)
                .build();

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("https://api.github.com")
                .addConverterFactory(GsonConverterFactory.create())
                .client(client)
                .build();

        RetrofitAPI retrofitAPI = retrofit.create(RetrofitAPI.class);
        retrofitAPI.getUserRepos("jwsoft91").enqueue(new Callback<List<JsonObject>>() {
            @Override
            public void onFailure(Call<List<JsonObject>> call, Throwable t) {
                Log.e("응답 실패 : ", "응답 실패");
            }

            @Override
            public void onResponse(Call<List<JsonObject>> call, Response<List<JsonObject>> response) {
                List<JsonObject> jsonArray = response.body();
                JsonObject jsonObject = jsonArray.get(0);
                Log.e("응답 성공 : ", jsonObject.get("name").toString());
            }
        });

    }

}

 

에러 발생

 

 

 

 

 

 

build.gradle (Module: app)

android {
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

위에 코드 추가하면 에러 해결됨.

 

stackoverflow.com/questions/59448845/no-static-method-metafactory

No static method metafactory

 

 

 

 

 

 

 

 

실행 후

???

위 에러 발생 시 앱 삭제 후 다시 실행하면 됨.

 

stackoverflow.com/questions/56266801/java-net-socketexception-socket-failed-eperm-operation-not-permitted

java.net.SocketException: socket failed: EPERM (Operation not permitted)

 

 

 

 

 

 

 

 

최종 실행 결과

실행 결과