How to use LZMA SDK to compress/decompress in Java

Question

http://www.7-zip.org/sdk.html This site provide a LZMA SDK for compress/decompress files, I would like to give it a shot but I am lost.

Anyone got experience on this

Answer 1

You can use this library instead. It is "outdated" but still works fine.

Maven dependency

    com.github.jponge
    lzma-java
    1.2

Utility class

import lzma.sdk.lzma.Decoder;
import lzma.streams.LzmaInputStream;
import lzma.streams.LzmaOutputStream;
import org.apache.commons.compress.utils.IOUtils;

import java.io.*;
import java.nio.file.Path;

public class LzmaCompressor
{
    private Path rawFilePath;
    private Path compressedFilePath;

    public LzmaCompressor(Path rawFilePath, Path compressedFilePath)
    {
        this.rawFilePath = rawFilePath;
        this.compressedFilePath = compressedFilePath;
    }

    public void compress() throws IOException
    {
        try (LzmaOutputStream outputStream = new LzmaOutputStream.Builder(
                new BufferedOutputStream(new FileOutputStream(compressedFilePath.toFile())))
                .useMaximalDictionarySize()
                .useMaximalFastBytes()
                .build();
             InputStream inputStream = new BufferedInputStream(new FileInputStream(rawFilePath.toFile())))
        {
            IOUtils.copy(inputStream, outputStream);
        }
    }

    public void decompress() throws IOException
    {
        try (LzmaInputStream inputStream = new LzmaInputStream(
                new BufferedInputStream(new FileInputStream(compressedFilePath.toFile())),
                new Decoder());
             OutputStream outputStream = new BufferedOutputStream(
                     new FileOutputStream(rawFilePath.toFile())))
        {
            IOUtils.copy(inputStream, outputStream);
        }
    }
}

Firstly you have to create a file with content to start compressing. You can use this website to generate random text.

Example compression and decompression

Path rawFile = Paths.get("raw.txt");
Path compressedFile = Paths.get("compressed.lzma");

LzmaCompressor lzmaCompressor = new LzmaCompressor(rawFile, compressedFile);
lzmaCompressor.compress();
lzmaCompressor.decompress();