Extract the Contents of ZIP/JAR Files Programmatically

Extract the Contents of ZIP/JAR Files Programmatically Suppose jarFile is the jar/zip file to be extracted. destDir is the path where it will be extracted:

java.util.jar.JarFile jar = new java.util.jar.JarFile(jarFile);
java.util.Enumeration enum = jar.entries();
while (enum.hasMoreElements()) {
java.util.jar.JarEntry file = (java.util.jar.JarEntry) enum.nextElement();
java.io.File f = new java.io.File(destDir + java.io.File.separator + file.getName());
if (file.isDirectory()) { // if its a directory, create it
f.mkdir();
continue;
}
java.io.InputStream is = jar.getInputStream(file); // get the input stream
java.io.FileOutputStream fos = new java.io.FileOutputStream(f);
while (is.available() > 0) { // write contents of 'is' to 'fos'
fos.write(is.read());
}
fos.close();
is.close();
}

source: [http://www.devx.com/tips/Tip/22124]

import java.io.*;
import java.util.*;
import java.util.jar.*;
import java.util.zip.ZipException;
public class jara {
    public static void main (String args[])throws IOException,ZipException
    {
       JarFile jarFile = new JarFile("dirp.jar");
       Enumeration en = jarFile.entries();
       while (en.hasMoreElements()) {
         String ent=proc(en.nextElement());
         if(ent.indexOf("/")>0)
         {
         String fil=ent.substring(0,ent.indexOf("/"));
         System.out.println(fil);
         File local=new File(fil);
         if(!local.exists())
         local.mkdirs();
         }
         if(ent.indexOf(".")>0)
         {
         int n=ent.length();
         String fil1=ent.substring(ent.lastIndexOf("/")+1,n);
         System.out.println(fil1);
          extract(jarFile.getName(),ent);
         }
        }
     }

       public static String proc(Object obj)
       {
       JarEntry entry = (JarEntry)obj;
       String name = entry.getName();
       System.out.println("\nEntry Name: "+name);
       return(name);
       }
       public static void extract(String jarName,String entryName)throws IOException,ZipException
      {
      JarFile jar = new JarFile(jarName);
          System.out.println(jarName + " opened.");
          try {
             // Get the entry and its input stream.
             JarEntry entry = jar.getJarEntry(entryName);
             // If the entry is not null, extract it. Otherwise, print a
             // message.
             if (entry != null) {
                // Get an input stream for the entry.
                InputStream entryStream = jar.getInputStream(entry);
                try {
                   // Create the output file (clobbering the file if it exists).
                   FileOutputStream file = new FileOutputStream(entry.getName());
                   try {
                      // Allocate a buffer for reading the entry data.
                      byte[] buffer = new byte[1024];
                      int bytesRead;
                      // Read the entry data and write it to the output file.
                      while ((bytesRead = entryStream.read(buffer)) != -1) {
                         file.write(buffer, 0, bytesRead);
                      }
                      System.out.println(entry.getName() + " extracted.");
                   }
                   finally {
                      file.close();
                   }
                }
                finally {
                   entryStream.close();
                }
             }
             else {
                System.out.println(entryName + " not found.");
             } // end if
          }
          finally {
             jar.close();
             System.out.println(jarName + " closed.");
          }
       }
     }