bzip2

package foo.bar;

import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.io.IOUtils;

public class SystemBzip2InputStream extends InputStream {

    final InputStream in;
    final Process exec;
    IOException readException = null;

    SystemBzip2InputStream(final InputStream in) throws IOException{
        this.in = in;
        exec = Runtime.getRuntime().exec(new String[]{"bzip2","-dc"});
        final Thread reader = new Thread(new Runnable() {

            public void run() {
                try {
                    IOUtils.copy(in, exec.getOutputStream());
                    exec.getOutputStream().close();
                } catch (IOException e) {
                    readException = e;
                }
            }
        });
        reader.start();
    }

    @Override
    public int read() throws IOException {
        checkInput();
        return exec.getInputStream().read();
    }

    private void checkInput() throws IOException {
        if(readException != null) {
            throw new IOException(readException);
        }
    }

    @Override
    public void close() throws IOException {
        super.close();
        in.close();
        exec.destroy();
    }

    @Override
    public int read(byte[] b) throws IOException {
        checkInput();
        return exec.getInputStream().read(b);
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        checkInput();
        return exec.getInputStream().read(b, off, len);
    }

    @Override
    public long skip(long n) throws IOException {
        checkInput();
        return exec.getInputStream().skip(n);
    }

    @Override
    public int available() throws IOException {
        checkInput();
        return exec.getInputStream().available();
    }

    @Override
    public synchronized void mark(int readlimit) {
        exec.getInputStream().mark(readlimit);
    }

    @Override
    public synchronized void reset() throws IOException {
        checkInput();
        exec.getInputStream().reset();
    }

    @Override
    public boolean markSupported() {
        return exec.getInputStream().markSupported();
    }

}