1 /*
2 * Copyright (c) 1997, 2015, 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;
27
28 import java.lang.reflect.Constructor;
29 import java.lang.reflect.InvocationTargetException;
30 import java.lang.reflect.Method;
31 import java.lang.reflect.Modifier;
32 import java.lang.ref.WeakReference;
33 import java.security.AccessController;
34 import java.security.PrivilegedAction;
35 import java.util.Map;
36 import java.util.WeakHashMap;
37 import java.util.logging.Level;
38 import java.util.logging.Logger;
39
40 import com.sun.xml.internal.bind.Util;
41
42 /**
43 * Creates new instances of classes.
44 *
45 * <p>
46 * This code handles the case where the class is not public or the constructor is
47 * not public.
48 *
49 * @since 2.0
50 * @author Kohsuke Kawaguchi
51 */
52 public final class ClassFactory {
53 private static final Class[] emptyClass = new Class[0];
54 private static final Object[] emptyObject = new Object[0];
55
56 private static final Logger logger = Util.getClassLogger();
57
58 /**
59 * Cache from a class to its default constructor.
60 *
61 * To avoid synchronization among threads, we use {@link ThreadLocal}.
62 */
63 private static final ThreadLocal<Map<Class, WeakReference<Constructor>>> tls = new ThreadLocal<Map<Class,WeakReference<Constructor>>>() {
64 @Override
65 public Map<Class,WeakReference<Constructor>> initialValue() {
66 return new WeakHashMap<Class,WeakReference<Constructor>>();
67 }
68 };
69
70 public static void cleanCache() {
71 if (tls != null) {
72 try {
73 tls.remove();
74 } catch (Exception e) {
75 logger.log(Level.WARNING, "Unable to clean Thread Local cache of classes used in Unmarshaller: {0}", e.getLocalizedMessage());
76 }
77 }
78 }
79
80 /**
81 * Creates a new instance of the class but throw exceptions without catching it.
82 */
83 public static <T> T create0( final Class<T> clazz ) throws IllegalAccessException, InvocationTargetException, InstantiationException {
84 Map<Class,WeakReference<Constructor>> m = tls.get();
85 Constructor<T> cons = null;
86 WeakReference<Constructor> consRef = m.get(clazz);
87 if(consRef!=null)
88 cons = consRef.get();
89 if(cons==null) {
90 cons = AccessController.doPrivileged(new PrivilegedAction<Constructor<T>>() {
91 @Override
92 public Constructor<T> run() {
93 try {
94 return clazz.getDeclaredConstructor(emptyClass);
95 } catch (NoSuchMethodException e) {
96 logger.log(Level.INFO,"No default constructor found on "+clazz,e);
97 NoSuchMethodError exp;
98 if(clazz.getDeclaringClass()!=null && !Modifier.isStatic(clazz.getModifiers())) {
99 exp = new NoSuchMethodError(Messages.NO_DEFAULT_CONSTRUCTOR_IN_INNER_CLASS
100 .format(clazz.getName()));
101 } else {
102 exp = new NoSuchMethodError(e.getMessage());
103 }
104 exp.initCause(e);
105 throw exp;
106 }
107 }
108 });
109
110 int classMod = clazz.getModifiers();
111
112 if(!Modifier.isPublic(classMod) || !Modifier.isPublic(cons.getModifiers())) {
113 // attempt to make it work even if the constructor is not accessible
114 try {
115 cons.setAccessible(true);
116 } catch(SecurityException e) {
117 // but if we don't have a permission to do so, work gracefully.
118 logger.log(Level.FINE,"Unable to make the constructor of "+clazz+" accessible",e);
119 throw e;
120 }
121 }
122
123 m.put(clazz,new WeakReference<Constructor>(cons));
124 }
125
126 return cons.newInstance(emptyObject);
127 }
128
129 /**
130 * The same as {@link #create0} but with an error handling to make
131 * the instantiation error fatal.
132 */
133 public static <T> T create( Class<T> clazz ) {
134 try {
135 return create0(clazz);
136 } catch (InstantiationException e) {
137 logger.log(Level.INFO,"failed to create a new instance of "+clazz,e);
138 throw new InstantiationError(e.toString());
139 } catch (IllegalAccessException e) {
140 logger.log(Level.INFO,"failed to create a new instance of "+clazz,e);
141 throw new IllegalAccessError(e.toString());
142 } catch (InvocationTargetException e) {
143 Throwable target = e.getTargetException();
144
145 // most likely an error on the user's code.
146 // just let it through for the ease of debugging
147 if(target instanceof RuntimeException)
148 throw (RuntimeException)target;
149
150 // error. just forward it for the ease of debugging
151 if(target instanceof Error)
152 throw (Error)target;
153
154 // a checked exception.
155 // not sure how we should report this error,
156 // but for now we just forward it by wrapping it into a runtime exception
157 throw new IllegalStateException(target);
158 }
159 }
160
161 /**
162 * Call a method in the factory class to get the object.
163 */
164 public static Object create(Method method) {
165 Throwable errorMsg;
166 try {
167 return method.invoke(null, emptyObject);
168 } catch (InvocationTargetException ive) {
169 Throwable target = ive.getTargetException();
170
171 if(target instanceof RuntimeException)
172 throw (RuntimeException)target;
173
174 if(target instanceof Error)
175 throw (Error)target;
176
177 throw new IllegalStateException(target);
178 } catch (IllegalAccessException e) {
179 logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),e);
180 throw new IllegalAccessError(e.toString());
181 } catch (IllegalArgumentException iae){
182 logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),iae);
183 errorMsg = iae;
184 } catch (NullPointerException npe){
185 logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),npe);
186 errorMsg = npe;
187 } catch (ExceptionInInitializerError eie){
188 logger.log(Level.INFO,"failed to create a new instance of "+method.getReturnType().getName(),eie);
189 errorMsg = eie;
190 }
191
192 NoSuchMethodError exp;
193 exp = new NoSuchMethodError(errorMsg.getMessage());
194 exp.initCause(errorMsg);
195 throw exp;
196 }
197
198 /**
199 * Infers the instanciable implementation class that can be assigned to the given field type.
200 *
201 * @return null
202 * if inference fails.
203 */
204 public static <T> Class<? extends T> inferImplClass(Class<T> fieldType, Class[] knownImplClasses) {
205 if(!fieldType.isInterface())
206 return fieldType;
207
208 for( Class<?> impl : knownImplClasses ) {
209 if(fieldType.isAssignableFrom(impl))
210 return impl.asSubclass(fieldType);
211 }
212
213 // if we can't find an implementation class,
214 // let's just hope that we will never need to create a new object,
215 // and returns null
216 return null;
217 }
218 }