public class TakePhoto extends AppCompatActivity implements View.OnClickListener{

private Button button, button2, button3;
private String encoded_string, image_name;
private Bitmap bitmap;
private File file;
private Uri file_uri;
private final int IMG_GALLERY = 1;
private final int IMG_CAMERA = 2;
private ImageView imageView;

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

    if(requestCode == IMG_GALLERY && resultCode == RESULT_OK && data != null){

        Uri uri_gallery = data.getData();
        try {
            bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri_gallery);
            imageView.setImageBitmap(bitmap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }else if(requestCode == IMG_CAMERA && resultCode == RESULT_OK && data != null){
        Uri uri_camera = data.getData();
        try {
            bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri_camera);
            imageView.setImageBitmap(bitmap);
        } catch (IOException e) {
            e.printStackTrace();
        }


    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_take_photo);

    button = (Button) findViewById(R.id.button);
    button2 = (Button) findViewById(R.id.button2);
    button3 = (Button) findViewById(R.id.button3);
    imageView = findViewById(R.id.imageShow);
    button.setOnClickListener(this);
    button2.setOnClickListener(this);
    button3.setOnClickListener(this);
}

private void selectImage(){

    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(intent, IMG_GALLERY);

}

private void takeImage(){
    Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(cameraIntent, IMG_CAMERA);
}

@Override
public void onClick(View v) {

    switch (v.getId()){

        case R.id.button:
            selectImage();
            break;

        case R.id.button2:
            uploadImage();
            break;

        case R.id.button3:
            takeImage();
            break;

    }


}

private String imageToString(Bitmap bitmap){
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream);
    byte[] imgBytes = byteArrayOutputStream.toByteArray();
    return Base64.encodeToString(imgBytes,Base64.DEFAULT);
}

private void uploadImage(){

    Map<String,String> map = new HashMap<String,String>();
    map.put("encoded_string",imageToString(bitmap));
    map.put("image_name","newimage");

    API_Service api_service = Client.getRetrofitInstance().create(API_Service.class);
    Call<ResponseBody> call = api_service.sendImage(map);
    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            Toast.makeText(TakePhoto.this, ""+response.body().getSuccess(), Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            Toast.makeText(TakePhoto.this, "hata", Toast.LENGTH_SHORT).show();
        }
    });

}