import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.jar.JarOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipCreator {
  public static void main(String[] args) {
    try (ZipOutputStream jos = new JarOutputStream(new FileOutputStream(new File("archive.jar")))) {
      ZipEntry entry = new ZipEntry("doc.txt");
      jos.putNextEntry(entry);
      jos.closeEntry();  // Empty jar File Archived (Java) warning issued here 
    }
    catch (IOException e) {
      e.printStackTrace();
    }

    try (ZipOutputStream jos = new ZipOutputStream(new FileOutputStream(new File("archive.jar")))) {
      ZipEntry entry = new ZipEntry("doc.txt");
      jos.putNextEntry(entry);
      jos.closeEntry();  // Empty zip File Archived (Java) warning issued here 
    }
    catch (IOException e) {
      e.printStackTrace();
    }

    try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(new File("archive.jar")));
         FileInputStream fis = new FileInputStream(new File("test.txt"))) {

      ZipEntry entry = new ZipEntry("doc.txt");
      jos.putNextEntry(entry);

      byte[] buf = new byte[1024];
      int len;
      while((len = fis.read(buf)) > 0)
        jos.write(buf, 0, len);

      jos.closeEntry();
    }
    catch (IOException e) {
      e.printStackTrace();
    }
  }
}