JAVA FILES UTILITY

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class Files {

/**
* Read full bytes of the given file.
*
* @param file a non-null file whose bytes will be read
* @return full bytes of the given file
* @throws FileNotFoundException if file does not exist
* @throws IOException if some issue occurs while reading from file
* @throws IllegalArgumentException if file is a directory
*/
public static byte[] readFully(File file) throws FileNotFoundException, IOException, IllegalArgumentException {
checkNotNull(file, "file is null");
checkArgument(file.isFile(), file.getPath() + " is not a file");

return ByteStreams.readFully(new FileInputStream(file));
}

/**
* Read full bytes of the file at given path.
*
* @param filePath non-null path of the file whose bytes will be read
* @return full bytes of file at given path
* @throws FileNotFoundException if file at given path does not exist
* @throws IOException if some issue occurs while reading from file
* @throws IllegalArgumentException if filePath points to a directory
*/
public static byte[] readFully(String filePath) throws FileNotFoundException, IOException, IllegalArgumentException {
checkNotNull(filePath, "filePath is null");

return readFully(new File(filePath));
}
}