Android RandomAccessFile Write copyBytes(RandomAccessFile srcFile, RandomAccessFile dstFile, int length, MessageDigest messageDigest)

Description

copy Bytes

License

Open Source License

Declaration

public static void copyBytes(RandomAccessFile srcFile,
            RandomAccessFile dstFile, int length,
            MessageDigest messageDigest) throws IOException 

Method Source Code

//package com.java2s;
/*/* ww w .  j ava  2  s  .c o m*/
 * Java build tools related to the Android operating system.
 * Copyright (C) 2011 DivDE <divde@free.fr>
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.io.IOException;
import java.io.RandomAccessFile;
import java.security.MessageDigest;

public class Main {
    public static int COPY_CHUNK_SIZE = 10000;

    public static void copyBytes(RandomAccessFile srcFile,
            RandomAccessFile dstFile, int length,
            MessageDigest messageDigest) throws IOException {
        byte[] chunk = new byte[Math.min(length, COPY_CHUNK_SIZE)];
        while (length > 0) {
            int sizeToRead = Math.min(length, COPY_CHUNK_SIZE);
            int sizeRead = srcFile.read(chunk, 0, sizeToRead);
            if (sizeRead == -1) {
                throw new IOException(
                        String.format(
                                "End of source file reached too early. Still %d bytes to read.",
                                length));
            }
            if (messageDigest != null) {
                messageDigest.update(chunk, 0, sizeRead);
            }
            dstFile.write(chunk, 0, sizeRead);
            length -= sizeRead;
        }
    }
}

Related

1. writeString(RandomAccessFile file, int size, String text)