1 /*
2 * Copyright (c) 1997, 2011, 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.runtime;
27
28 import java.util.HashMap;
29
30 import javax.xml.bind.ValidationEvent;
31 import javax.xml.bind.ValidationEventHandler;
32 import javax.xml.bind.ValidationEventLocator;
33 import javax.xml.bind.annotation.adapters.XmlAdapter;
34 import javax.xml.bind.helpers.ValidationEventImpl;
35
36 import com.sun.xml.internal.bind.v2.ClassFactory;
37 import com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext;
38
39 import org.xml.sax.ErrorHandler;
40 import org.xml.sax.SAXException;
41 import org.xml.sax.SAXParseException;
42
43 /**
44 * Object that coordinates the marshalling/unmarshalling.
45 *
46 * <p>
47 * This class takes care of the logic that allows code to obtain
48 * {@link UnmarshallingContext} and {@link XMLSerializer} instances
49 * during the unmarshalling/marshalling.
50 *
51 * <p>
52 * This is done by using a {@link ThreadLocal}. Therefore one unmarshalling/marshalling
53 * episode has to be done from the beginning till end by the same thread.
54 * (Note that the same {@link Coordinator} can be then used by a different thread
55 * for an entirely different episode.)
56 *
57 * This class also maintains the user-configured instances of {@link XmlAdapter}s.
58 *
59 * <p>
60 * This class implements {@link ErrorHandler} and propages erros to this object
61 * as the {@link ValidationEventHandler}, which will be implemented in a derived class.
62 *
63 * @author Kohsuke Kawaguchi
64 */
65 public abstract class Coordinator implements ErrorHandler, ValidationEventHandler {
66
67 private final HashMap<Class<? extends XmlAdapter>,XmlAdapter> adapters =
68 new HashMap<Class<? extends XmlAdapter>,XmlAdapter>();
69
70
71 public final XmlAdapter putAdapter(Class<? extends XmlAdapter> c, XmlAdapter a) {
72 if(a==null)
73 return adapters.remove(c);
74 else
75 return adapters.put(c,a);
76 }
77
78 /**
79 * Gets the instance of the adapter.
80 *
81 * @return
82 * always non-null.
83 */
84 public final <T extends XmlAdapter> T getAdapter(Class<T> key) {
85 T v = key.cast(adapters.get(key));
86 if(v==null) {
87 v = ClassFactory.create(key);
88 putAdapter(key,v);
89 }
90 return v;
91 }
92
93 public <T extends XmlAdapter> boolean containsAdapter(Class<T> type) {
94 return adapters.containsKey(type);
95 }
96
97 /**
98 * The {@link Coordinator} in charge before this {@link Coordinator}.
99 */
100 private Object old;
101
102 /**
103 * A 'pointer' to a {@link Coordinator} that keeps track of the currently active {@link Coordinator}.
104 * Having this improves the runtime performance.
105 */
106 private Object[] table;
107
108 /**
109 * When we set {@link #table} to null, record who did it.
110 * This is for trouble-shooting a possible concurrency issue reported at:
111 * http://forums.java.net/jive/thread.jspa?threadID=15132
112 */
113 public Exception guyWhoSetTheTableToNull;
114
115 /**
116 * Associates this {@link Coordinator} with the current thread.
117 * Should be called at the very beginning of the episode.
118 */
119 protected final void setThreadAffinity() {
120 table = activeTable.get();
121 assert table!=null;
122 }
123
124 /**
125 * Dis-associate this {@link Coordinator} with the current thread.
126 * Sohuld be called at the end of the episode to avoid memory leak.
127 */
128 protected final void resetThreadAffinity() {
129 if (activeTable != null) {
130 activeTable.remove();
131 }
132 if(debugTableNPE)
133 guyWhoSetTheTableToNull = new Exception(); // remember that we set it to null
134 table = null;
135 }
136
137 /**
138 * Called whenever an execution flow enters the realm of this {@link Coordinator}.
139 */
140 protected final void pushCoordinator() {
141 old = table[0];
142 table[0] = this;
143 }
144
145 /**
146 * Called whenever an execution flow exits the realm of this {@link Coordinator}.
147 */
148 protected final void popCoordinator() {
149 assert table[0]==this;
150 table[0] = old;
151 old = null; // avoid memory leak
152 }
153
154 public static Coordinator _getInstance() {
155 return (Coordinator) activeTable.get()[0];
156 }
157
158 // this much is necessary to avoid calling get and set twice when we push.
159 private static final ThreadLocal<Object[]> activeTable = new ThreadLocal<Object[]>() {
160 @Override
161 public Object[] initialValue() {
162 return new Object[1];
163 }
164 };
165
166 //
167 //
168 // ErrorHandler implementation
169 //
170 //
171 /**
172 * Gets the current location. Used for reporting the error source location.
173 */
174 protected abstract ValidationEventLocator getLocation();
175
176 public final void error(SAXParseException exception) throws SAXException {
177 propagateEvent( ValidationEvent.ERROR, exception );
178 }
179
180 public final void warning(SAXParseException exception) throws SAXException {
181 propagateEvent( ValidationEvent.WARNING, exception );
182 }
183
184 public final void fatalError(SAXParseException exception) throws SAXException {
185 propagateEvent( ValidationEvent.FATAL_ERROR, exception );
186 }
187
188 private void propagateEvent( int severity, SAXParseException saxException )
189 throws SAXException {
190
191 ValidationEventImpl ve =
192 new ValidationEventImpl( severity, saxException.getMessage(), getLocation() );
193
194 Exception e = saxException.getException();
195 if( e != null ) {
196 ve.setLinkedException( e );
197 } else {
198 ve.setLinkedException( saxException );
199 }
200
201 // call the client's event handler. If it returns false, then bail-out
202 // and terminate the unmarshal operation.
203 boolean result = handleEvent( ve );
204 if( ! result ) {
205 // bail-out of the parse with a SAX exception, but convert it into
206 // an UnmarshalException back in in the AbstractUnmarshaller
207 throw saxException;
208 }
209 }
210
211 public static boolean debugTableNPE;
212
213 static {
214 try {
215 debugTableNPE = Boolean.getBoolean(Coordinator.class.getName()+".debugTableNPE");
216 } catch (SecurityException t) {
217 }
218 }
219 }