갤러리 이미지 가져오기

* MainActivity.java

public class MainActivity extends AppCompatActivity implements AutoPermissionsListener {

    ImageView imageView;

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

        imageView = findViewById(R.id.imageView);

        Button button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openGallery();
            }
        });

        AutoPermissions.Companion.loadAllPermissions(this, 101);
    }

    public void openGallery() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);

        startActivityForResult(intent, 101);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == 101) {
            if (resultCode == RESULT_OK) {
                Uri fileUri = data.getData();

                ContentResolver resolver = getContentResolver();

                try {
                    InputStream inputStream = resolver.openInputStream(fileUri);
                    Bitmap bitmap = BitmapFactory.decodeStream(inputStream);

                    imageView.setImageBitmap(bitmap);

                    inputStream.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        AutoPermissions.Companion.parsePermissions(this, requestCode, permissions, this);
    }

    @Override
    public void onDenied(int requestCode, String[] permissions) {
        Toast.makeText(this, "permissions denied : " + permissions.length, Toast.LENGTH_LONG).show();
    }

    @Override
    public void onGranted(int requestCode, String[] permissions) {
        Toast.makeText(this, "permissions granted : " + permissions.length, Toast.LENGTH_LONG).show();
    }

}

* activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="이미지 선택" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:srcCompat="@mipmap/ic_launcher" />

</LinearLayout>

* AndroidManifest.xml

<!-- 외장 SD 카드 권한 -->
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

* Gradle

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.pedroSG94:AutoPermissions:1.0.3'
}