【Java/Android】AWSのS3バケットにファイルをアップロードする手順。〜AWS, AndroidStudio設定とコード〜

        <service
            android:name="com.amazonaws.mobileconnectors.s3.transferutility.TransferService"
            android:enabled="true" />
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
</manifest>

dependencies {
    implementation ('com.amazonaws:aws-android-sdk-mobile-client:2.6.7@aar') { transitive = true }
    implementation 'com.amazonaws:aws-android-sdk-s3:2.6.+'
    implementation 'com.amazonaws:aws-android-sdk-cognito:2.6.+'
    implementation 'com.amazonaws:aws-android-sdk-s3:2.2.+'
}

flutter {
    source '../..'
}

package com.example.test;

import androidx.appcompat.app.AppCompatActivity;
import android.util.Log;
import android.os.Bundle;
import android.os.AsyncTask;
import android.content.Intent;
import android.content.Context;
import android.content.IntentFilter;
import android.content.ContextWrapper;
import androidx.annotation.NonNull;
import android.device.ScanManager;
import android.device.scanner.configuration.PropertyID;
import android.device.scanner.configuration.Triggering;
//AWS_S3アップロード関連で必要なライブラリ
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.mobile.client.AWSMobileClient;
import com.amazonaws.mobileconnectors.s3.transferutility.TransferState;
import com.amazonaws.mobileconnectors.s3.transferutility.TransferUtility;
import com.amazonaws.mobileconnectors.s3.transferutility.TransferListener;
import com.amazonaws.mobileconnectors.s3.transferutility.TransferObserver;
//////////////////////////////////////////////////////////////////////////

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        String accessKey = "[IAMで作成したアクセスキー]";
        String secKey = "[IAMで作成したシークレットキー]";
        String buchet = "[作成したバケット名]";
        //アップロード用のpath（仮で動画ファイルにしていますがここはなんでもOKです。）
        String path = "/data/user/0/com.example.test/app_flutter/Videos/1.mp4";
        BasicAWSCredentials basicAWSCredentials = new BasicAWSCredentials(accessKey, secKey);　　　　　// AWS認証情報の作成
        AmazonS3Client s3Client = new AmazonS3Client(basicAWSCredentials);
　　　　　//クライアント接続用オブジェクト
        TransferUtility transferUtility = new TransferUtility(s3Client, getApplicationContext());//転送用オブジェクト
        //バケット名,S3内のファイル名(デイレクトり指定も可能),uploadファイル
　　　　　TransferObserver observer = transferUtility.upload(buchet, "[upload時のファイル名]", new java.io.File(path));
        
        //log出力用
        observer.setTransferListener(new TransferListener() {
            @Override
            public void onStateChanged(int id, TransferState state) {
                Log.d("AwsSample", "status: "+state);
            }//完了時(COMPLETED)
            @Override
            public void onProgressChanged(int id, long bytesCurrent, long bytesTotal) {
                Log.d("AwsSample", "progress: "+id+" bytesCurrent:"+bytesCurrent+" bytesTotal:"+bytesTotal);
            }//転送時
            @Override
            public void onError(int id, Exception ex) {
                ex.printStackTrace();
            }//失敗時
        });
    }
}