duke@1: /*
ohair@158:  * Copyright (c) 2000, 2004, Oracle and/or its affiliates. All rights reserved.
duke@1:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1:  *
duke@1:  * This code is free software; you can redistribute it and/or modify it
duke@1:  * under the terms of the GNU General Public License version 2 only, as
ohair@158:  * published by the Free Software Foundation.  Oracle designates this
duke@1:  * particular file as subject to the "Classpath" exception as provided
ohair@158:  * by Oracle in the LICENSE file that accompanied this code.
duke@1:  *
duke@1:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@1:  * version 2 for more details (a copy is included in the LICENSE file that
duke@1:  * accompanied this code).
duke@1:  *
duke@1:  * You should have received a copy of the GNU General Public License version
duke@1:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@1:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1:  *
ohair@158:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@158:  * or visit www.oracle.com if you need additional information or have any
ohair@158:  * questions.
duke@1:  */
duke@1: package sun.rmi.rmic.iiop;
duke@1: 
duke@1: import java.io.*;
duke@1: import sun.tools.java.ClassPath ;
duke@1: import sun.tools.java.ClassFile ;
duke@1: 
duke@1: /**
duke@1:  * A ClassLoader that will ultimately use a given sun.tools.java.ClassPath to
duke@1:  * find the desired file.  This works for any JAR files specified in the given
duke@1:  * ClassPath as well -- reusing all of that wonderful sun.tools.java code.
duke@1:  *
duke@1:  *@author Everett Anderson
duke@1:  */
duke@1: public class ClassPathLoader extends ClassLoader
duke@1: {
duke@1:     private ClassPath classPath;
duke@1: 
duke@1:     public ClassPathLoader(ClassPath classPath) {
duke@1:         this.classPath = classPath;
duke@1:     }
duke@1: 
duke@1:     // Called by the super class
duke@1:     protected Class findClass(String name) throws ClassNotFoundException
duke@1:     {
duke@1:         byte[] b = loadClassData(name);
duke@1:         return defineClass(name, b, 0, b.length);
duke@1:     }
duke@1: 
duke@1:     /**
duke@1:      * Load the class with the given fully qualified name from the ClassPath.
duke@1:      */
duke@1:     private byte[] loadClassData(String className)
duke@1:         throws ClassNotFoundException
duke@1:     {
duke@1:         // Build the file name and subdirectory from the
duke@1:         // class name
duke@1:         String filename = className.replace('.', File.separatorChar)
duke@1:                           + ".class";
duke@1: 
duke@1:         // Have ClassPath find the file for us, and wrap it in a
duke@1:         // ClassFile.  Note:  This is where it looks inside jar files that
duke@1:         // are specified in the path.
duke@1:         ClassFile classFile = classPath.getFile(filename);
duke@1: 
duke@1:         if (classFile != null) {
duke@1: 
duke@1:             // Provide the most specific reason for failure in addition
duke@1:             // to ClassNotFound
duke@1:             Exception reportedError = null;
duke@1:             byte data[] = null;
duke@1: 
duke@1:             try {
duke@1:                 // ClassFile is beautiful because it shields us from
duke@1:                 // knowing if it's a separate file or an entry in a
duke@1:                 // jar file.
duke@1:                 DataInputStream input
duke@1:                     = new DataInputStream(classFile.getInputStream());
duke@1: 
duke@1:                 // Can't rely on input available() since it will be
duke@1:                 // something unusual if it's a jar file!  May need
duke@1:                 // to worry about a possible problem if someone
duke@1:                 // makes a jar file entry with a size greater than
duke@1:                 // max int.
duke@1:                 data = new byte[(int)classFile.length()];
duke@1: 
duke@1:                 try {
duke@1:                     input.readFully(data);
duke@1:                 } catch (IOException ex) {
duke@1:                     // Something actually went wrong reading the file.  This
duke@1:                     // is a real error so save it to report it.
duke@1:                     data = null;
duke@1:                     reportedError = ex;
duke@1:                 } finally {
duke@1:                     // Just don't care if there's an exception on close!
duke@1:                     // I hate that close can throw an IOException!
duke@1:                     try { input.close(); } catch (IOException ex) {}
duke@1:                 }
duke@1:             } catch (IOException ex) {
duke@1:                 // Couldn't get the input stream for the file.  This is
duke@1:                 // probably also a real error.
duke@1:                 reportedError = ex;
duke@1:             }
duke@1: 
duke@1:             if (data == null)
duke@1:                 throw new ClassNotFoundException(className, reportedError);
duke@1: 
duke@1:             return data;
duke@1:         }
duke@1: 
duke@1:         // Couldn't find the file in the class path.
duke@1:         throw new ClassNotFoundException(className);
duke@1:     }
duke@1: }