Java by API/java.util.jar/JarOutputStream

JarOutputStream: putNextEntry(ZipEntry ze)

 
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
public class Main {
  public static int BUFFER_SIZE = 10240;
  void createJarArchive(File archiveFile, File[] tobeJared) throws Exception {
    byte buffer[] = new byte[BUFFER_SIZE];
    FileOutputStream stream = new FileOutputStream(archiveFile);
    JarOutputStream out = new JarOutputStream(stream, new Manifest());
    for (int i = 0; i < tobeJared.length; i++) {
      if (tobeJared[i] == null || !tobeJared[i].exists() || tobeJared[i].isDirectory())
        continue; // Just in case...
      JarEntry jarAdd = new JarEntry(tobeJared[i].getName());
      jarAdd.setTime(tobeJared[i].lastModified());
      out.putNextEntry(jarAdd);
      FileInputStream in = new FileInputStream(tobeJared[i]);
      while (true) {
        int nRead = in.read(buffer, 0, buffer.length);
        if (nRead <= 0)
          break;
        out.write(buffer, 0, nRead);
      }
      in.close();
    }
    out.close();
    stream.close();
  }
}

new JarOutputStream(OutputStream out)

 
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.jar.JarOutputStream;
import java.util.jar.Pack200;
import java.util.zip.GZIPInputStream;
public class Main {
  public static void main(String[] args) throws Exception {
    String inName = args[0];
    String outName;
    if (inName.endsWith(".pack.gz")) {
      outName = inName.substring(0, inName.length() - 8);
    } else if (inName.endsWith(".pack")) {
      outName = inName.substring(0, inName.length() - 5);
    } else {
      outName = inName + ".unpacked";
    }
    JarOutputStream out = null;
    InputStream in = null;
    Pack200.Unpacker unpacker = Pack200.newUnpacker();
    out = new JarOutputStream(new FileOutputStream(outName));
    in = new FileInputStream(inName);
    if (inName.endsWith(".gz"))
      in = new GZIPInputStream(in);
    unpacker.unpack(in, out);
    out.close();
  }
}