Java File Write via ByteBuffer writeComment(File zipFile, String comment)

Description

write Comment

License

Open Source License

Declaration

public static void writeComment(File zipFile, String comment) throws IOException 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.io.*;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class Main {
    private static final byte[] COMMENT_SIGN = new byte[] { 99, 104, 97, 110, 110, 101, 108 };

    public static void writeComment(File zipFile, String comment) throws IOException {
        // {@see java.util.zip.ZipOutputStream.writeEND}
        byte[] data = comment.getBytes("utf-8");
        final RandomAccessFile raf = new RandomAccessFile(zipFile, "rw");
        raf.seek(zipFile.length() - 2);//from ww w. j a  va2  s  .c om
        // write zip comment length
        // (content field length + length field length + sign field length)
        writeShort(data.length + 2 + COMMENT_SIGN.length, raf);
        // write content
        writeBytes(data, raf);
        // write content length
        writeShort(data.length, raf);
        // write sign bytes
        writeBytes(COMMENT_SIGN, raf);
        raf.close();
    }

    private static void writeShort(int i, DataOutput out) throws IOException {
        ByteBuffer bb = ByteBuffer.allocate(2).order(ByteOrder.LITTLE_ENDIAN);
        bb.putShort((short) i);
        out.write(bb.array());
    }

    private static void writeBytes(byte[] data, DataOutput out) throws IOException {
        out.write(data);
    }
}

Related

1. write(Path file, String content)
2. write(SeekableByteChannel channel, long start, byte[] bytes)
3. write24BitInteger(int integer, ByteOrder order)
4. writeByte(WritableByteChannel channel, byte value)
5. writeBytes(Path file, byte[] bytes)
6. writeDataLengthsToHeader(FileOutputStream fpo)
7. writeDelimitedToOutputStream(byte[] bytes, OutputStream outputStream)
8. writeDouble(BufferedWriter bw, double[] buf)
9. writeEmpty()