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.unmarshaller;
27
28 import java.util.Collection;
29 import java.util.Collections;
30
31 import javax.xml.bind.Unmarshaller;
32 import javax.xml.bind.ValidationEvent;
33 import javax.xml.bind.helpers.ValidationEventImpl;
34 import javax.xml.namespace.QName;
35
36 import com.sun.xml.internal.bind.v2.runtime.JaxBeanInfo;
37
38 import org.xml.sax.SAXException;
39
40 /**
41 * @author Kohsuke Kawaguchi
42 */
43 public abstract class Loader {
44
45 // allow derived classes to change it later
46 protected boolean expectText;
47
48 protected Loader(boolean expectText) {
49 this.expectText = expectText;
50 }
51
52 protected Loader() {
53 }
54
55 //
56 //
57 //
58 // Contract
59 //
60 //
61 //
62 /**
63 * Called when the loader is activated, which is when a new start tag is seen
64 * and when the parent designated this loader as the child loader.
65 *
66 * <p>
67 * The callee may change <tt>state.loader</tt> to designate another {@link Loader}
68 * for the processing. It's the responsibility of the callee to forward the startElement
69 * event in such a case.
70 *
71 * @param ea
72 * info about the start tag. never null.
73 */
74 public void startElement(UnmarshallingContext.State state,TagName ea) throws SAXException {
75 }
76
77 /**
78 * Called when this loaderis an active loaderand we see a new child start tag.
79 *
80 * <p>
81 * The callee is expected to designate another loaderas a loaderthat processes
82 * this element, then it should also register a {@link Receiver}.
83 * The designated loaderwill become an active loader.
84 *
85 * <p>
86 * The default implementation reports an error saying an element is unexpected.
87 */
88 public void childElement(UnmarshallingContext.State state, TagName ea) throws SAXException {
89 // notify the error, then recover by ignoring the whole element.
90 reportUnexpectedChildElement(ea, true);
91 state.loader = Discarder.INSTANCE;
92 state.receiver = null;
93 }
94
95 @SuppressWarnings({"StringEquality"})
96 protected final void reportUnexpectedChildElement(TagName ea, boolean canRecover) throws SAXException {
97 if(canRecover && !UnmarshallingContext.getInstance().parent.hasEventHandler())
98 // this error happens particurly often (when input documents contain a lot of unexpected elements to be ignored),
99 // so don't bother computing all the messages and etc if we know that
100 // there's no event handler to receive the error in the end. See #286
101 return;
102 if(ea.uri!=ea.uri.intern() || ea.local!=ea.local.intern())
103 reportError(Messages.UNINTERNED_STRINGS.format(), canRecover );
104 else
105 reportError(Messages.UNEXPECTED_ELEMENT.format(ea.uri,ea.local,computeExpectedElements()), canRecover );
106 }
107
108 /**
109 * Returns a set of tag names expected as possible child elements in this context.
110 */
111 public Collection<QName> getExpectedChildElements() {
112 return Collections.emptyList();
113 }
114
115 /**
116 * Returns a set of tag names expected as possible child elements in this context.
117 */
118 public Collection<QName> getExpectedAttributes() {
119 return Collections.emptyList();
120 }
121
122 /**
123 * Called when this loaderis an active loaderand we see a chunk of text.
124 *
125 * The runtime makes sure that adjacent characters (even those separated
126 * by comments, PIs, etc) are reported as one event.
127 * IOW, you won't see two text event calls in a row.
128 */
129 public void text(UnmarshallingContext.State state, CharSequence text) throws SAXException {
130 // make str printable
131 text = text.toString().replace('\r',' ').replace('\n',' ').replace('\t',' ').trim();
132 reportError(Messages.UNEXPECTED_TEXT.format(text), true );
133 }
134
135 /**
136 * True if this loader expects the {@link #text(UnmarshallingContext.State, CharSequence)} method
137 * to be called. False otherwise.
138 */
139 public final boolean expectText() {
140 return expectText;
141 }
142
143
144 /**
145 * Called when this loaderis an active loaderand we see an end tag.
146 */
147 public void leaveElement(UnmarshallingContext.State state, TagName ea) throws SAXException {
148 }
149
150
151
152
153
154
155
156
157
158
159 //
160 //
161 //
162 // utility methods
163 //
164 //
165 //
166 /**
167 * Computes the names of possible root elements for a better error diagnosis.
168 */
169 private String computeExpectedElements() {
170 StringBuilder r = new StringBuilder();
171
172 for( QName n : getExpectedChildElements() ) {
173 if(r.length()!=0) r.append(',');
174 r.append("<{").append(n.getNamespaceURI()).append('}').append(n.getLocalPart()).append('>');
175 }
176 if(r.length()==0) {
177 return "(none)";
178 }
179
180 return r.toString();
181 }
182
183 /**
184 * Fires the beforeUnmarshal event if necessary.
185 *
186 * @param state
187 * state of the newly create child object.
188 */
189 protected final void fireBeforeUnmarshal(JaxBeanInfo beanInfo, Object child, UnmarshallingContext.State state) throws SAXException {
190 if(beanInfo.lookForLifecycleMethods()) {
191 UnmarshallingContext context = state.getContext();
192 Unmarshaller.Listener listener = context.parent.getListener();
193 if(beanInfo.hasBeforeUnmarshalMethod()) {
194 beanInfo.invokeBeforeUnmarshalMethod(context.parent, child, state.prev.target);
195 }
196 if(listener!=null) {
197 listener.beforeUnmarshal(child, state.prev.target);
198 }
199 }
200 }
201
202 /**
203 * Fires the afterUnmarshal event if necessary.
204 *
205 * @param state
206 * state of the parent object
207 */
208 protected final void fireAfterUnmarshal(JaxBeanInfo beanInfo, Object child, UnmarshallingContext.State state) throws SAXException {
209 // fire the event callback
210 if(beanInfo.lookForLifecycleMethods()) {
211 UnmarshallingContext context = state.getContext();
212 Unmarshaller.Listener listener = context.parent.getListener();
213 if(beanInfo.hasAfterUnmarshalMethod()) {
214 beanInfo.invokeAfterUnmarshalMethod(context.parent, child, state.target);
215 }
216 if(listener!=null)
217 listener.afterUnmarshal(child, state.target);
218 }
219 }
220
221
222 /**
223 * Last resort when something goes terribly wrong within the unmarshaller.
224 */
225 protected static void handleGenericException(Exception e) throws SAXException {
226 handleGenericException(e,false);
227 }
228
229 public static void handleGenericException(Exception e, boolean canRecover) throws SAXException {
230 reportError(e.getMessage(), e, canRecover );
231 }
232
233 public static void handleGenericError(Error e) throws SAXException {
234 reportError(e.getMessage(), false);
235 }
236
237 protected static void reportError(String msg, boolean canRecover) throws SAXException {
238 reportError(msg, null, canRecover );
239 }
240
241 public static void reportError(String msg, Exception nested, boolean canRecover) throws SAXException {
242 UnmarshallingContext context = UnmarshallingContext.getInstance();
243 context.handleEvent( new ValidationEventImpl(
244 canRecover? ValidationEvent.ERROR : ValidationEvent.FATAL_ERROR,
245 msg,
246 context.getLocator().getLocation(),
247 nested ), canRecover );
248 }
249
250 /**
251 * This method is called by the generated derived class
252 * when a datatype parse method throws an exception.
253 */
254 protected static void handleParseConversionException(UnmarshallingContext.State state, Exception e) throws SAXException {
255 // wrap it into a ParseConversionEvent and report it
256 state.getContext().handleError(e);
257 }
258 }