libjava/gnu/gcj/runtime/SharedLibLoader.java

   1 /* Copyright (C) 2001, 2003  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 import java.io.IOException;
  11 import java.net.MalformedURLException;
  12 import java.net.URL;
  13 import java.security.CodeSource;
  14 import java.util.Enumeration;
  15 import java.util.Vector;
  16
  17 /**
  18  * A ClassLoader backed by a gcj-compiled shared library.
  19  * @author Per Bothner <per@bothner.com>, Brainfood Inc.
  20  */
  21
  22 public class SharedLibLoader extends ClassLoader
  23 {
  24   /** Load a shared library, and associate a ClassLoader with it.
  25    * @param libname named of shared library (passed to dlopen)
  26    * @param parent the parent ClassLoader
  27    * @parem flags passed to dlopen
  28    */
  29   public SharedLibLoader(String libname, ClassLoader parent, int flags)
  30   {
  31     super(parent);
  32     URL url;
  33     try
  34       {
  35         url = new URL("file", "", libname);
  36       }
  37     catch (MalformedURLException _)
  38       {
  39         url = null;
  40       }
  41     helper = SharedLibHelper.findHelper(this, libname,
  42                                         new CodeSource(url, null), true);
  43   }
  44
  45   /** Load a shared library, and asociate a ClassLoader with it.
  46    * @param libname named of shared library (passed to dlopen)
  47    */
  48   public SharedLibLoader(String libname)
  49   {
  50     this(libname, getSystemClassLoader(), 0);
  51   }
  52
  53   public Class findClass(String name)
  54     throws ClassNotFoundException
  55   {
  56     Class cls = helper.findClass(name);
  57     if (cls == null)
  58       throw new ClassNotFoundException(name);
  59     return cls;
  60   }
  61
  62   public URL findResource (String name)
  63   {
  64     return helper.findResource(name);
  65   }
  66
  67   public Enumeration findResources (String name) throws IOException
  68   {
  69     URL url = findResource(name);
  70     if (url == null)
  71       return null;
  72     Vector v = new Vector(1);
  73     v.add(url);
  74     return v.elements();
  75   }
  76
  77   /** The helper that does the work for us.  */
  78   SharedLibHelper helper;
  79 }