1 /*

     2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package com.sun.tools.internal.xjc.api.util;

    27 

    28 import java.io.ByteArrayOutputStream;

    29 import java.io.IOException;

    30 import java.io.InputStream;

    31 import java.io.File;

    32 import java.net.URL;

    33 import java.net.URLClassLoader;

    34 import java.net.MalformedURLException;

    35 

    36 import com.sun.istack.internal.Nullable;

    37 

    38 /**

    39  * {@link ClassLoader} that loads Annotation Processing and specified classes

    40  * both into the same classloader, so that they can reference each other.

    41  *

    42  * @author Bhakti Mehta

    43  * @since 2.0 beta

    44  */

    45 public final class ApClassLoader extends URLClassLoader {

    46     /**

    47      * List of package prefixes we want to mask the

    48      * parent classLoader from loading

    49      */

    50     private final String[] packagePrefixes;

    51 

    52     /**

    53      *

    54      * @param packagePrefixes

    55      *      The package prefixes that are forced to resolve within this class loader.

    56      * @param parent

    57      *      The parent class loader to delegate to. Null to indicate bootstrap classloader.

    58      */

    59     public ApClassLoader(@Nullable ClassLoader parent, String[] packagePrefixes) throws ToolsJarNotFoundException {

    60         super(getToolsJar(parent),parent);

    61         if(getURLs().length==0)

    62             // if tools.jar was found in our classloader, no need to create

    63             // a parallel classes

    64             this.packagePrefixes = new String[0];

    65         else

    66             this.packagePrefixes = packagePrefixes;

    67     }

    68 

    69     public Class loadClass(String className) throws ClassNotFoundException {

    70         for( String prefix : packagePrefixes ) {

    71             if (className.startsWith(prefix) ) {

    72                 // we need to load those classes in this class loader

    73                 // without delegation.

    74                 return findClass(className);

    75             }

    76         }

    77 

    78         return super.loadClass(className);

    79 

    80     }

    81 

    82     protected Class findClass(String name) throws ClassNotFoundException {

    83 

    84         StringBuilder sb = new StringBuilder(name.length() + 6);

    85         sb.append(name.replace('.','/')).append(".class");

    86 

    87         InputStream is = getResourceAsStream(sb.toString());

    88         if (is==null)

    89             throw new ClassNotFoundException("Class not found" + sb);

    90 

    91         try {

    92             ByteArrayOutputStream baos = new ByteArrayOutputStream();

    93             byte[] buf = new byte[1024];

    94             int len;

    95             while((len=is.read(buf))>=0)

    96                 baos.write(buf,0,len);

    97 

    98             buf = baos.toByteArray();

    99 

   100             // define package if not defined yet

   101             int i = name.lastIndexOf('.');

   102             if (i != -1) {

   103                 String pkgname = name.substring(0, i);

   104                 Package pkg = getPackage(pkgname);

   105                 if(pkg==null)

   106                     definePackage(pkgname, null, null, null, null, null, null, null);

   107             }

   108 

   109             return defineClass(name,buf,0,buf.length);

   110         } catch (IOException e) {

   111             throw new ClassNotFoundException(name,e);

   112         } finally {

   113             try {

   114                 is.close();

   115             } catch (IOException ioe) {

   116                 //ignore

   117             }

   118         }

   119     }

   120 

   121     /**

   122      * Returns a class loader that can load classes from JDK tools.jar.

   123      * @param parent

   124      */

   125     private static URL[] getToolsJar(@Nullable ClassLoader parent) throws ToolsJarNotFoundException {

   126 

   127         try {

   128             Class.forName("com.sun.tools.javac.Main", false, parent);

   129             return new URL[0];

   130             // we can already load them in the parent class loader.

   131             // so no need to look for tools.jar.

   132             // this happens when we are run inside IDE/Ant, or

   133             // in Mac OS.

   134         } catch (ClassNotFoundException e) {

   135             // otherwise try to find tools.jar

   136         }

   137 

   138         File jreHome = new File(System.getProperty("java.home"));

   139         File toolsJar = new File( jreHome.getParent(), "lib/tools.jar" );

   140 

   141         if (!toolsJar.exists()) {

   142             throw new ToolsJarNotFoundException(toolsJar);

   143         }

   144 

   145         try {

   146             return new URL[]{toolsJar.toURL()};

   147         } catch (MalformedURLException e) {

   148             // impossible

   149             throw new AssertionError(e);

   150         }

   151     }

   152 }