Geek Answers Handbook

Java LZ4 compression using I / O streams

I use jpountz LZ4 to try to compress files and I want to read and output files using input and output streams of Java files. I tried to find a solution on the Internet, but did not find anything, I found a previous question on how to implement LZ4 correctly, and I took this and tried to change it to use streams, but I'm not sure if this is correct or if it even works .

When you start compression in a text file, it displays a file with some characters that are missing or replaced by characters

ðHello world Heðo world Hello ðrld Hello worlðHello worl

but when you run it with an image file, it throws an error outside the bounds. I also could not get decompression to work, as it gives error decoding offset 3 of the input buffer.

Here is my code, any help would be appreciated thanks

public void LZ4Compress(InputStream in, OutputStream out){
    int noBytesRead = 0;        //number of bytes read from input
    int noBytesProcessed = 0;   //number of bytes processed
    try {
        while ((noBytesRead = in.read(inputBuffer)) >= 0) {
            noBytesProcessed = inputBuffer.length;
            decompressedLength = inputBuffer.length;
            outputBuffer = compress(inputBuffer, decompressedLength);
            out.write(outputBuffer, 0, noBytesRead);
        }
        out.flush();
        in.close();
        out.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

public void LZ4decompress(InputStream in, OutputStream out){
    int noBytesRead = 0;        //number of bytes read from input
    try {
        while((noBytesRead = in.read(inputBuffer)) >= 0){
            noBytesProcessed = inputBuffer.length;
            outputBuffer = decompress(inputBuffer);
            out.write(outputBuffer, 0, noBytesRead);

        }
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

public static byte[] compress(byte[] src, int srcLen) {
    decompressedLength = srcLen;
    int maxCompressedLength = compressor.maxCompressedLength(decompressedLength);
    byte[] compressed = new byte[maxCompressedLength];
    int compressLen = compressor.compress(src, 0, decompressedLength, compressed, 0, maxCompressedLength);
    byte[] finalCompressedArray = Arrays.copyOf(compressed, compressLen);
    return finalCompressedArray;
}

private static LZ4SafeDecompressor decompressor = factory.safeDecompressor();

public static byte[] decompress(byte[] finalCompressedArray) {
    byte[] restored = new byte[finalCompressedArray.length];
    restored = decompressor.decompress(finalCompressedArray, finalCompressedArray.length);
    return restored;
}
+4
2

, , / LZ4block

public static void LZ4compress(String filename, String lz4file){
    byte[] buf = new byte[2048];
    try {
        String outFilename = lz4file;
        LZ4BlockOutputStream out = new LZ4BlockOutputStream(new FileOutputStream(outFilename), 32*1024*1024);
        FileInputStream in = new FileInputStream(filename);
        int len;
        while((len = in.read(buf)) > 0){
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
    } catch (IOException e) {

    }
}

public static void LZ4Uncompress(String lz4file, String filename){
    byte[] buf = new byte[2048];
    try {
        String outFilename = filename;
        LZ4BlockInputStream in = new LZ4BlockInputStream(new FileInputStream(lz4file));
        FileOutputStream out = new FileOutputStream(outFilename);
        int len;
        while((len = in.read(buf)) > 0){
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
    } catch (IOException e) {

    }
}
+2

, , :

 outputBuffer = compress(inputBuffer, decompressedLength);
 out.write(outputBuffer, 0, noBytesRead);

outputBuffer . :

out.write(outputBuffer);
+1

More articles:


All Articles