libjava/gnu/gcj/runtime/HelperClassLoader.java

   1 /* Copyright (C) 2005  Free Software Foundation
   2
   3    This file is part of libgcj.
   4
   5 This software is copyrighted work licensed under the terms of the
   6 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   7 details.  */
   8
   9 package gnu.gcj.runtime;
  10
  11 import java.io.File;
  12 import java.io.FilenameFilter;
  13 import java.io.IOException;
  14 import java.net.URL;
  15 import java.net.URLClassLoader;
  16 import java.util.StringTokenizer;
  17
  18 /**
  19  * This is a URLClassLoader that has an extra helper method for
  20  * handling things like java.ext.dirs.
  21  */
  22 class HelperClassLoader extends URLClassLoader
  23 {
  24   HelperClassLoader()
  25   {
  26     super(new URL[0]);
  27   }
  28
  29   HelperClassLoader(ClassLoader parent)
  30   {
  31     super(new URL[0], parent);
  32   }
  33
  34   /**
  35    * This is a helper method that adds all the jar and zip files from
  36    * a given list of paths to this class loader.  The paths are taken
  37    * from a system property whose name is provided as an argument.
  38    */
  39   final void addDirectoriesFromProperty(String propName)
  40   {
  41     StringTokenizer st
  42       = new StringTokenizer (System.getProperty (propName, ""),
  43                              File.pathSeparator);
  44     try
  45       {
  46         while (st.hasMoreElements ())
  47           {
  48             String dirname = st.nextToken ();
  49             File dir = new File (dirname);
  50             if (dir.exists ())
  51               {
  52                 if (! dirname.endsWith (File.separator))
  53                   dirname = dirname + File.separator;
  54                 String files[] = dir.list (new FilenameFilter ()
  55                   {
  56                     public boolean accept (File dir, String name)
  57                     {
  58                       return name.endsWith (".jar") || name.endsWith (".zip");
  59                     }
  60                   });
  61                 for (int i = files.length - 1; i >= 0; i--)
  62                   addURL(new URL("file", "", -1, dirname + files[i]));
  63               }
  64           }
  65       }
  66     catch (java.net.MalformedURLException x)
  67       {
  68         // This should never happen.
  69         throw new RuntimeException(x);
  70       }
  71   }
  72 }