Exploring Jar Contents

This solution contains code through which you can first reach a particular directory whose name has to be provided and that should exist.
In that directory you can shorlist the files with extension .jar.Next you need to explore the contents of the Jar file.Here in this solution the jar contains images
and we get the list of files and add them to a java.util.List object.

import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;


public class ExploreJarContent {
 
 public static void main(String[] args) throws IOException {
  ExploreJarContent exploreJar = new ExploreJarContent();
  List<String> resourceList = new ArrayList<String>();
  String resourceName = "/images/";
  exploreJar.loadResourceJar(resourceName, resourceList);
 }

 /**
  * @param resourceName
  * @param resourceList
  */
 private void loadResourceJar(String resourceName, List<String> resourceList) {

  URL url = this.getClass().getResource(resourceName);
  String[] jarName = null;
  System.out.println("-----url--- " + url);
  int jarNameIndex = 0;
  StringBuffer jarUrl;
  // To get only the jar file
  String strFile;
  if (null != url) {
   strFile = url.getFile();
   if (null != strFile) {
    File file = new File(strFile);
    File[] listOfFiles = file.listFiles();
    jarName = new String[listOfFiles.length];
    for (int i = 0; i < listOfFiles.length; i++) {
     if (listOfFiles[i].isFile()) {
      if (listOfFiles[i].getName().endsWith((".jar"))) {
       jarName[jarNameIndex] = listOfFiles[i].getName();
       jarNameIndex++;
      }
     }
    }
   }
  }
  if (null != jarName) {
   for (int i = 0; i < jarName.length; i++) {
    if (null == jarName[i])
     break;
    jarUrl = new StringBuffer();
    jarUrl.append("jar:").append(url).append(jarName[i]).append(
      "!/");
    URL url_jar = null;

    try {
     url_jar = new URL(jarUrl.toString());
    } catch (MalformedURLException e1) {
     e1.printStackTrace();
    }

    try {
     if (url_jar.openConnection() instanceof JarURLConnection) {
      JarURLConnection jarUrlConn = (JarURLConnection) url_jar
        .openConnection();
      if (jarUrlConn != null) {
       JarFile jar = jarUrlConn.getJarFile();
       Enumeration enm = jar.entries();

       while (enm.hasMoreElements()) {
        JarEntry entry = (JarEntry) enm.nextElement();
        if (!entry.isDirectory()) {
         String entryName = entry.getName();

         resourceList.add("/" + entryName);

         System.out.println("----entry Name---"
           + entryName);
        }
       }

      }
     }
    } catch (IOException e) {
     e.printStackTrace();
    }
    // }//end if
   }// end of for loop
  }

 }
}