SaveToFileTransformer.java

package io.fotoapparat.result.transformer;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import io.fotoapparat.photo.Photo;
import io.fotoapparat.util.ExifOrientationWriter;

/**
 * Saves {@link Photo} to file.
 */
public class SaveToFileTransformer implements Transformer<Photo, Void> {

    private final File file;
    private final ExifOrientationWriter exifOrientationWriter;

    SaveToFileTransformer(File file,
                          ExifOrientationWriter exifOrientationWriter) {
        this.file = file;
        this.exifOrientationWriter = exifOrientationWriter;
    }

    /**
     * @param file Output file.
     */
    public static SaveToFileTransformer create(File file) {
        return new SaveToFileTransformer(
                file,
                new ExifOrientationWriter()
        );
    }

    @Override
    public Void transform(Photo input) {
        BufferedOutputStream outputStream = outputStream();

        try {
            saveImage(input, outputStream);

            exifOrientationWriter.writeExifOrientation(file, input);
        } catch (IOException e) {
            throw new FileSaveException(e);
        }

        return null;
    }

    private void saveImage(Photo input, BufferedOutputStream outputStream) throws IOException {
        try {
            outputStream.write(input.encodedImage);
            outputStream.flush();
        } finally {
            outputStream.close();
        }
    }

    private BufferedOutputStream outputStream() {
        try {
            return new BufferedOutputStream(
                    new FileOutputStream(file)
            );
        } catch (FileNotFoundException e) {
            throw new FileSaveException(e);
        }
    }

    /**
     * Thrown when there is a problem while saving the file.
     */
    public static class FileSaveException extends RuntimeException {

        public FileSaveException(Throwable cause) {
            super(cause);
        }

    }

}