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.xml.internal.bind.v2.model.annotation;
  27 
  28 import java.lang.annotation.Annotation;
  29 import java.lang.reflect.InvocationHandler;
  30 import java.lang.reflect.InvocationTargetException;
  31 import java.lang.reflect.Method;
  32 import java.lang.reflect.Proxy;
  33 import java.lang.reflect.Modifier;
  34 import java.util.HashMap;
  35 import java.util.Map;
  36 
  37 import com.sun.xml.internal.bind.v2.runtime.Location;
  38 
  39 /**
  40  * {@link Annotation} that also implements {@link Locatable}.
  41  *
  42  * @author Kohsuke Kawaguchi
  43  */
  44 public class LocatableAnnotation implements InvocationHandler, Locatable, Location {
  45     private final Annotation core;
  46 
  47     private final Locatable upstream;
  48 
  49     /**
  50      * Wraps the annotation into a proxy so that the returned object will also implement
  51      * {@link Locatable}.
  52      */
  53     public static <A extends Annotation> A create( A annotation, Locatable parentSourcePos ) {
  54         if(annotation==null)    return null;
  55         Class<? extends Annotation> type = annotation.annotationType();
  56         if(quicks.containsKey(type)) {
  57             // use the existing proxy implementation if available
  58             return (A)quicks.get(type).newInstance(parentSourcePos,annotation);
  59         }
  60 
  61         // otherwise take the slow route
  62 
  63         ClassLoader cl = SecureLoader.getClassClassLoader(LocatableAnnotation.class);
  64 
  65         try {
  66             Class loadableT = Class.forName(type.getName(), false, cl);
  67             if(loadableT !=type)
  68                 return annotation;  // annotation type not loadable from this class loader
  69 
  70             return (A)Proxy.newProxyInstance(cl,
  71                     new Class[]{ type, Locatable.class },
  72                     new LocatableAnnotation(annotation,parentSourcePos));
  73         } catch (ClassNotFoundException e) {
  74             // annotation not loadable
  75             return annotation;
  76         } catch (IllegalArgumentException e) {
  77             // Proxy.newProxyInstance throws this if it cannot resolve this annotation
  78             // in this classloader
  79             return annotation;
  80         }
  81 
  82     }
  83 
  84     LocatableAnnotation(Annotation core, Locatable upstream) {
  85         this.core = core;
  86         this.upstream = upstream;
  87     }
  88 
  89     public Locatable getUpstream() {
  90         return upstream;
  91     }
  92 
  93     public Location getLocation() {
  94         return this;
  95     }
  96 
  97     public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
  98         try {
  99             if(method.getDeclaringClass()==Locatable.class)
 100                 return method.invoke(this,args);
 101             if(Modifier.isStatic(method.getModifiers()))
 102                 // malicious code can pass in a static Method object.
 103                 // doing method.invoke() would end up executing it,
 104                 // so we need to protect against it.
 105                 throw new IllegalArgumentException();
 106 
 107             return method.invoke(core,args);
 108         } catch (InvocationTargetException e) {
 109             if(e.getTargetException()!=null)
 110                 throw e.getTargetException();
 111             throw e;
 112         }
 113     }
 114 
 115     public String toString() {
 116         return core.toString();
 117     }
 118 
 119 
 120     /**
 121      * List of {@link Quick} implementations keyed by their annotation type.
 122      */
 123     private static final Map<Class,Quick> quicks = new HashMap<Class, Quick>();
 124 
 125     static {
 126         for( Quick q : Init.getAll() ) {
 127             quicks.put(q.annotationType(),q);
 128         }
 129     }
 130 }