This program copies jar from the source folder to the destination folder.

copy.java

package jarcopier;


import java.io.*;
import java.util.Enumeration;
import java.util.jar.*;
 
/*
 * @author Shubham Shah
 */
public class copy  {
   public static void main(String[] args) throws Exception {
       File shubhamDir = new File(sourceLocation);
       File destDir = new File(destinationLocation);
       copy cp = new copy();
       if (shubhamDir.isFile()) {
           cp.copyJarFile(new JarFile(shubhamDir), destDir);
       } else if (shubhamDir.isDirectory()) {
           File[] files = shubhamDir.listFiles(new FilenameFilter() {
               public boolean accept(File dir, String name) {
                   return name.endsWith(".jar");
               }
           });
           for (File f : files) {
        	   System.out.println("Shubham File f-->"+f);
               cp.copyJarFile(new JarFile(f), destDir);
           }
       }
   }
 
   public  void copyJarFile(JarFile jarFile, File destDir) throws IOException {
       String fileName = jarFile.getName();
       String fileNameLastPart = fileName.substring(fileName.lastIndexOf(File.separator));
       File destFile = new File(destDir, fileNameLastPart);
 
       JarOutputStream jos = new JarOutputStream(new FileOutputStream(destFile));
       Enumeration<JarEntry> entries = jarFile.entries();
 
       while (entries.hasMoreElements()) {
           JarEntry entry = entries.nextElement();
           InputStream is = jarFile.getInputStream(entry);
 
           jos.putNextEntry(new JarEntry(entry.getName()));
           byte[] buffer = new byte[4096];
           int bytesRead = 0;
           while ((bytesRead = is.read(buffer)) != -1) {
               jos.write(buffer, 0, bytesRead);
           }
           is.close();
           jos.flush();
           jos.closeEntry();
       }
       jos.close();
   }
}