/*

  * Copyright 2001,2004 The Apache Software Foundation.

  * 

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  * 

  *      http://www.apache.org/licenses/LICENSE-2.0

  * 

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.commons.jjar;

 import java.lang.Package;

 import java.util.ArrayList;

 import java.util.Iterator;

 import java.util.Collection;

 import java.util.Map;

 import java.util.List;

 import java.util.StringTokenizer;

 import java.util.Enumeration;

 import java.util.jar.JarFile;

 import java.util.jar.Manifest;

 import java.util.jar.Attributes;

 import java.util.jar.JarInputStream;

 import java.util.jar.JarOutputStream;

 import java.util.jar.JarEntry;

 import java.io.File;

 import java.io.FileOutputStream;

 import java.io.BufferedInputStream;

 import java.io.BufferedOutputStream;

 import java.io.InputStream;

 import java.io.ByteArrayOutputStream;

 import java.net.JarURLConnection;

 import java.net.URLConnection;

 import java.net.URL;

 /**

  *  classpath support for JJAR.  This is currently a jumble - will

  *  clean up.

  *

  *  @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>

  *  @version $Id: ClasspathUtil.java 155454 2005-02-26 13:23:34Z dirkv $ 

  */

 public class ClasspathUtil

 {

     /**

      *  current default repository

      */

     public static String getDefaultRepository()

     {

         return "http://jakarta.apache.org/jjar/";

     }

     /**

      *  lists the jars currently in the classpath

      */

     public static void listJars( String path )

     {

        List jars = getJarList( path );

        Iterator i = jars.iterator();

        while( i.hasNext() )

        {

            String jar =  (String) i.next();

            System.out.println(" inspecting :  " + jar );

        }

        return;

     }

     /**

      *  checks to see if the classpath <code>path</code> contains

      *  the package / version

      */

     public static boolean containsVersionedJar( String path, String pkg, String version)

     {

         List jars = getJarList( path );

        /*

         *  now, with this set of jars, see if we can find those that match

         *  the package name

         */

         Iterator i = jars.iterator();

         while( i.hasNext() )

         {

             String jar =  (String) i.next();

             try

             {

                 URL url = new URL("jar:file:" + jar + "!/");

                 JarURLConnection conn  = (JarURLConnection) url.openConnection(); 

                 if (packageMatch( conn, pkg, version ) )

                 {

                     // System.out.println( jar + " : pkg = " + pkg + " ver = " + version );

                     return true;

                 }

             }

             catch( Exception e )

             {

                 //System.out.println("Exception (continuing) : " + e );

             }

         }

         return false;

     }

     /**

      *  returns a JJARPackage( info ) for a given jar

      */

     public static JJARPackage getPackage( String jarname )

         throws Exception

     {

         URL url = new URL("jar:file:" + jarname + "!/");

         JarURLConnection conn  = (JarURLConnection) url.openConnection(); 

         return getPackage( conn );

     }

     public static JJARPackage getPackage( JarURLConnection jarConn )

         throws Exception

     {

         if (jarConn == null)

             return null;

         Manifest mfst = jarConn.getManifest();

         if (mfst == null)

         {

             return null;

         }

         /*

          * get the attributes we care about

          */

         Attributes att = mfst.getMainAttributes();

         String jarpkg = att.getValue( Attributes.Name.IMPLEMENTATION_TITLE );

         String jarver = att.getValue( Attributes.Name.IMPLEMENTATION_VERSION );

         if (jarpkg == null || jarver == null)

         {

             /*

              * unusable

              */

             return null;

         }

         return new JJARPackage( jarpkg, jarver );

     }

     /**

      *  determines if two packages are equal

      */

     public static boolean packageMatch( JarURLConnection jarConn, String pkg, String version )

         throws Exception

     {

         JJARPackage jjarp = getPackage( jarConn );

         if ( jjarp == null)

             return false;

         /*

          *  compare

          */

         return jjarp.equals( pkg, version );

     } 

     /**

      *  returns a list of jars in the specified claspath.

      *  will check the system classpath by default

      */

     public static List getJarList( String path )

     {

         if (path == null)

         {

             path = "java.class.path";

         }

         String classpath = System.getProperty( path );

         String pathSep = System.getProperty("path.separator");

         /*

          *  take the classpath, and look for jars

          */

         StringTokenizer st = new StringTokenizer( classpath, pathSep );

         ArrayList jars = new ArrayList();

         while( st.hasMoreTokens() )

         {

             String foo = st.nextToken();

             if ( foo.indexOf("jar") != -1 )

                 jars.add(foo);

         }

         return jars;

     }    

     public static void main( String args[] )

     {

         /*

          *  see if the default classpath has the jar we need

          */

         if ( ClasspathUtil.containsVersionedJar( null, "commons-beanutils", "0.1") )

             System.out.println("Found commons-beanutils v0.1");

         else

         {

             /*

              * didn't find it...

              */

             try

             {

                 /*

                  *  so go to the repository

                  */

                 URL url = new URL("jar:file:/home/gmj/jakarta/jakarta-commons/beanutils/dist/commons-beanutils.jar!/");

                 JarURLConnection conn  = (JarURLConnection) url.openConnection(); 

                 /*

                  * ensure that it's right

                  */

                 if (!packageMatch( conn, "commons-beanutils", "0.1" ))

                 {

                     System.out.println("repository doesn't have it");

                     return;

                 }

                 System.out.println("jar in repository correct. Fetching");

                 String jar = "commons-beanutils-0.1.jar";

                 url = new URL("file:/home/gmj/jakarta/jakarta-commons/beanutils/dist/commons-beanutils.jar");

                 URLConnection uconn  = (URLConnection) url.openConnection(); 

                 Transport.fetchJar( uconn, jar );

                 /*

                  *  add to classpath and verify

                  */

                 String classpath = System.getProperty( "java.class.path" );

                 String pathSep = System.getProperty("path.separator");

                 classpath = classpath + pathSep + jar;

                 System.setProperty("java.class.path", classpath);

                 if ( ClasspathUtil.containsVersionedJar( null, "commons-beanutils", "0.1") )

                     System.out.println("Found commons-beanutils v0.1");

             }

             catch( Exception e )

             {

                 System.out.println("exception " + e );

             }

         }

     }

     /**

      *  doesn't work.  don't use

      */

     public static boolean markJar( String jarname, String packagename, String version )

         throws Exception

     {

         JarFile jf = new JarFile( jarname );

         Manifest mfst = jf.getManifest();

         if (mfst == null)

         {

             return false;

         }

         /*

          * set the attributes we care about

          */

         Attributes att = mfst.getMainAttributes();

         Object a = att.put( Attributes.Name.IMPLEMENTATION_TITLE, packagename );

         Object b = att.put( Attributes.Name.IMPLEMENTATION_VERSION, version );

         System.out.println(" Object a " + a );

         System.out.println(" Object b " + b );

         JarOutputStream jos = new JarOutputStream( new FileOutputStream( new File( jarname + "-jjar")));

         byte[] buffer = new byte[1024]; 

         int bytesRead; 

         for( Enumeration e = jf.entries(); e.hasMoreElements(); )

         {

             JarEntry entry = (JarEntry) e.nextElement(); 

             if( entry.getName().equals("META-INF/MANIFEST.MF"))

             {

                 ByteArrayOutputStream baos = new ByteArrayOutputStream();

                 mfst.write( baos );

                 JarEntry ee = new JarEntry( entry );

                 ee.setSize(baos.size() );

                 jos.putNextEntry(ee );

                 mfst.write( jos );

                 continue;

             }

             System.out.println(" Name : " + entry.getName() );

             InputStream entryStream = jf.getInputStream( entry); 

             jos.putNextEntry(entry );

             while ((bytesRead = entryStream.read(buffer)) != -1) 

             { 

                 jos.write(buffer, 0, bytesRead);

             }

         }

         jos.close();

         jf.close();

         return true;

     }   

 }