1 /*
2 * Copyright (c) 1997, 2014, 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 {@code state.loader} 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.setLoader(Discarder.INSTANCE);
92 state.setReceiver(null);
93 }
94
95 @SuppressWarnings({"StringEquality"})
96 protected final void reportUnexpectedChildElement(TagName ea, boolean canRecover) throws SAXException {
97 if (canRecover) {
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 UnmarshallingContext context = UnmarshallingContext.getInstance();
102 if (!context.parent.hasEventHandler() // is somebody listening?
103 || !context.shouldErrorBeReported()) // should we report error?
104 return;
105 }
106 if(ea.uri!=ea.uri.intern() || ea.local!=ea.local.intern())
107 reportError(Messages.UNINTERNED_STRINGS.format(), canRecover );
108 else
109 reportError(Messages.UNEXPECTED_ELEMENT.format(ea.uri,ea.local,computeExpectedElements()), canRecover );
110 }
111
112 /**
113 * Returns a set of tag names expected as possible child elements in this context.
114 */
115 public Collection<QName> getExpectedChildElements() {
116 return Collections.emptyList();
117 }
118
119 /**
120 * Returns a set of tag names expected as possible child elements in this context.
121 */
122 public Collection<QName> getExpectedAttributes() {
123 return Collections.emptyList();
124 }
125
126 /**
127 * Called when this loaderis an active loaderand we see a chunk of text.
128 *
129 * The runtime makes sure that adjacent characters (even those separated
130 * by comments, PIs, etc) are reported as one event.
131 * IOW, you won't see two text event calls in a row.
132 */
133 public void text(UnmarshallingContext.State state, CharSequence text) throws SAXException {
134 // make str printable
135 text = text.toString().replace('\r',' ').replace('\n',' ').replace('\t',' ').trim();
136 reportError(Messages.UNEXPECTED_TEXT.format(text), true );
137 }
138
139 /**
140 * True if this loader expects the {@link #text(UnmarshallingContext.State, CharSequence)} method
141 * to be called. False otherwise.
142 */
143 public final boolean expectText() {
144 return expectText;
145 }
146
147
148 /**
149 * Called when this loaderis an active loaderand we see an end tag.
150 */
151 public void leaveElement(UnmarshallingContext.State state, TagName ea) throws SAXException {
152 }
153
154
155
156
157
158
159
160
161
162
163 //
164 //
165 //
166 // utility methods
167 //
168 //
169 //
170 /**
171 * Computes the names of possible root elements for a better error diagnosis.
172 */
173 private String computeExpectedElements() {
174 StringBuilder r = new StringBuilder();
175
176 for( QName n : getExpectedChildElements() ) {
177 if(r.length()!=0) r.append(',');
178 r.append("<{").append(n.getNamespaceURI()).append('}').append(n.getLocalPart()).append('>');
179 }
180 if(r.length()==0) {
181 return "(none)";
182 }
183
184 return r.toString();
185 }
186
187 /**
188 * Fires the beforeUnmarshal event if necessary.
189 *
190 * @param state
191 * state of the newly create child object.
192 */
193 protected final void fireBeforeUnmarshal(JaxBeanInfo beanInfo, Object child, UnmarshallingContext.State state) throws SAXException {
194 if(beanInfo.lookForLifecycleMethods()) {
195 UnmarshallingContext context = state.getContext();
196 Unmarshaller.Listener listener = context.parent.getListener();
197 if(beanInfo.hasBeforeUnmarshalMethod()) {
198 beanInfo.invokeBeforeUnmarshalMethod(context.parent, child, state.getPrev().getTarget());
199 }
200 if(listener!=null) {
201 listener.beforeUnmarshal(child, state.getPrev().getTarget());
202 }
203 }
204 }
205
206 /**
207 * Fires the afterUnmarshal event if necessary.
208 *
209 * @param state
210 * state of the parent object
211 */
212 protected final void fireAfterUnmarshal(JaxBeanInfo beanInfo, Object child, UnmarshallingContext.State state) throws SAXException {
213 // fire the event callback
214 if(beanInfo.lookForLifecycleMethods()) {
215 UnmarshallingContext context = state.getContext();
216 Unmarshaller.Listener listener = context.parent.getListener();
217 if(beanInfo.hasAfterUnmarshalMethod()) {
218 beanInfo.invokeAfterUnmarshalMethod(context.parent, child, state.getTarget());
219 }
220 if(listener!=null)
221 listener.afterUnmarshal(child, state.getTarget());
222 }
223 }
224
225
226 /**
227 * Last resort when something goes terribly wrong within the unmarshaller.
228 */
229 protected static void handleGenericException(Exception e) throws SAXException {
230 handleGenericException(e,false);
231 }
232
233 public static void handleGenericException(Exception e, boolean canRecover) throws SAXException {
234 reportError(e.getMessage(), e, canRecover );
235 }
236
237 public static void handleGenericError(Error e) throws SAXException {
238 reportError(e.getMessage(), false);
239 }
240
241 protected static void reportError(String msg, boolean canRecover) throws SAXException {
242 reportError(msg, null, canRecover );
243 }
244
245 public static void reportError(String msg, Exception nested, boolean canRecover) throws SAXException {
246 UnmarshallingContext context = UnmarshallingContext.getInstance();
247 context.handleEvent( new ValidationEventImpl(
248 canRecover? ValidationEvent.ERROR : ValidationEvent.FATAL_ERROR,
249 msg,
250 context.getLocator().getLocation(),
251 nested ), canRecover );
252 }
253
254 /**
255 * This method is called by the generated derived class
256 * when a datatype parse method throws an exception.
257 */
258 protected static void handleParseConversionException(UnmarshallingContext.State state, Exception e) throws SAXException {
259 // wrap it into a ParseConversionEvent and report it
260 state.getContext().handleError(e);
261 }
262 }