eclipse_jdt/src/org/eclipse/jdt/core/dom/TryStatement.java

1	/*******************************************************************************
2	* Copyright (c) 2000, 2017 IBM Corporation and others.
3	*
4	* This program and the accompanying materials
5	* are made available under the terms of the Eclipse Public License 2.0
6	* which accompanies this distribution, and is available at
7	* https://www.eclipse.org/legal/epl-2.0/
8	*
9	* SPDX-License-Identifier: EPL-2.0
10	*
11	* Contributors:
12	* IBM Corporation - initial API and implementation
13	*******************************************************************************/
14
15	package org.eclipse.jdt.core.dom;
16
17	import java.util.ArrayList;
18	import java.util.List;
19
20	/**
21	* Try statement AST node type.
22	* <pre>
23	* TryStatement:
24	* <b>try</b> [ <b>(</b> Resources <b>)</b> ]
25	* Block
26	* [ { CatchClause } ]
27	* [ <b>finally</b> Block ]
28	* </pre>
29	*
30	* <p>
31	* Not all node arrangements will represent legal Java constructs. In particular,
32	* at least one resource, catch clause, or finally block must be present.</p>
33	*
34	* <p>A resource is either a {@link VariableDeclarationExpression} or (since JLS9) a {@link Name}.</p>
35	*
36	* @since 2.0
37	* @noinstantiate This class is not intended to be instantiated by clients.
38	* @noextend This class is not intended to be subclassed by clients.
39	*/
40	@SuppressWarnings({"rawtypes", "unchecked"})
41	public class TryStatement extends Statement {
42
43
44	/**
45	* The "resources" structural property of this node type (element type: {@link VariableDeclarationExpression}) (added in JLS4 API).
46	* @deprecated In the JLS9 API, this property is replaced by {@link #RESOURCES2_PROPERTY}.
47	* @since 3.7.1
48	*/
49	public static final ChildListPropertyDescriptor RESOURCES_PROPERTY =
50	new ChildListPropertyDescriptor(TryStatement.class, "resources", VariableDeclarationExpression.class, CYCLE_RISK); //$NON-NLS-1$
51
52	/**
53	* The "resources" structural property of this node type (element type: {@link Expression}) (added in JLS9 API).
54	* @since 3.14
55	*/
56	public static final ChildListPropertyDescriptor RESOURCES2_PROPERTY =
57	new ChildListPropertyDescriptor(TryStatement.class, "resources", Expression.class, CYCLE_RISK); //$NON-NLS-1$
58
59	/**
60	* The "body" structural property of this node type (child type: {@link Block}).
61	* @since 3.0
62	*/
63	public static final ChildPropertyDescriptor BODY_PROPERTY =
64	new ChildPropertyDescriptor(TryStatement.class, "body", Block.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
65
66	/**
67	* The "catchClauses" structural property of this node type (element type: {@link CatchClause}).
68	* @since 3.0
69	*/
70	public static final ChildListPropertyDescriptor CATCH_CLAUSES_PROPERTY =
71	new ChildListPropertyDescriptor(TryStatement.class, "catchClauses", CatchClause.class, CYCLE_RISK); //$NON-NLS-1$
72
73	/**
74	* The "finally" structural property of this node type (child type: {@link Block}).
75	* @since 3.0
76	*/
77	public static final ChildPropertyDescriptor FINALLY_PROPERTY =
78	new ChildPropertyDescriptor(TryStatement.class, "finally", Block.class, OPTIONAL, CYCLE_RISK); //$NON-NLS-1$
79
80	/**
81	* A list of property descriptors (element type:
82	* {@link StructuralPropertyDescriptor}),
83	* or null if uninitialized.
84	*/
85	private static final List PROPERTY_DESCRIPTORS;
86
87	/**
88	* A list of property descriptors (element type:
89	* {@link StructuralPropertyDescriptor}),
90	* or null if uninitialized.
91	* @since 3.7
92	*/
93	private static final List PROPERTY_DESCRIPTORS_4_0;
94
95	/**
96	* A list of property descriptors (element type:
97	* {@link StructuralPropertyDescriptor}),
98	* or null if uninitialized.
99	* @since 3.14
100	*/
101	private static final List PROPERTY_DESCRIPTORS_9_0;
102
103	static {
104	List propertyList = new ArrayList(4);
105	createPropertyList(TryStatement.class, propertyList);
106	addProperty(BODY_PROPERTY, propertyList);
107	addProperty(CATCH_CLAUSES_PROPERTY, propertyList);
108	addProperty(FINALLY_PROPERTY, propertyList);
109	PROPERTY_DESCRIPTORS = reapPropertyList(propertyList);
110
111	propertyList = new ArrayList(5);
112	createPropertyList(TryStatement.class, propertyList);
113	addProperty(RESOURCES_PROPERTY, propertyList);
114	addProperty(BODY_PROPERTY, propertyList);
115	addProperty(CATCH_CLAUSES_PROPERTY, propertyList);
116	addProperty(FINALLY_PROPERTY, propertyList);
117	PROPERTY_DESCRIPTORS_4_0 = reapPropertyList(propertyList);
118
119	propertyList = new ArrayList(5);
120	createPropertyList(TryStatement.class, propertyList);
121	addProperty(RESOURCES2_PROPERTY, propertyList);
122	addProperty(BODY_PROPERTY, propertyList);
123	addProperty(CATCH_CLAUSES_PROPERTY, propertyList);
124	addProperty(FINALLY_PROPERTY, propertyList);
125	PROPERTY_DESCRIPTORS_9_0 = reapPropertyList(propertyList);
126	}
127
128	/**
129	* Returns a list of structural property descriptors for this node type.
130	* Clients must not modify the result.
131	*
132	* @param apiLevel the API level; one of the
133	* <code>AST.JLS*</code> constants
134	* @return a list of property descriptors (element type:
135	* {@link StructuralPropertyDescriptor})
136	* @since 3.0
137	*/
138	public static List propertyDescriptors(int apiLevel) {
139	switch (apiLevel) {
140	case AST.JLS2_INTERNAL :
141	case AST.JLS3_INTERNAL :
142	return PROPERTY_DESCRIPTORS;
143	case AST.JLS4_INTERNAL :
144	case AST.JLS8_INTERNAL :
145	return PROPERTY_DESCRIPTORS_4_0;
146	default :
147	return PROPERTY_DESCRIPTORS_9_0;
148	}
149	}
150
151	/**
152	* The resource expressions (element type: {@link Expression}).
153	* Null in JLS2 and JLS3. Added in JLS4.
154	* In the deprecated JLS4 and JLS8 APIs, this used to be
155	* (element type: {@link VariableDeclarationExpression}).
156	* Defaults to an empty list (see constructor).
157	* @since 3.7
158	*/
159	private ASTNode.NodeList resources = null;
160
161	/**
162	* The body; lazily initialized; defaults to an empty block.
163	*/
164	private Block body = null;
165
166	/**
167	* The catch clauses (element type: {@link CatchClause}).
168	* Defaults to an empty list.
169	*/
170	private ASTNode.NodeList catchClauses =
171	new ASTNode.NodeList(CATCH_CLAUSES_PROPERTY);
172
173	/**
174	* The finally block, or <code>null</code> if none.
175	* Defaults to none.
176	*/
177	private Block optionalFinallyBody = null;
178
179
180	/**
181	* Creates a new AST node for a try statement owned by the given
182	* AST. By default, the try statement has no resources, an empty block, no catch
183	* clauses, and no finally block.
184	* <p>
185	* N.B. This constructor is package-private.
186	* </p>
187	*
188	* @param ast the AST that is to own this node
189	*/
190	TryStatement(AST ast) {
191	super(ast);
192	if (ast.apiLevel >= AST.JLS9_INTERNAL) {
193	this.resources = new ASTNode.NodeList(RESOURCES2_PROPERTY);
194	} else if (ast.apiLevel >= AST.JLS4_INTERNAL) {
195	this.resources = new ASTNode.NodeList(RESOURCES_PROPERTY);
196	}
197	}
198
199	@Override
200	final List internalStructuralPropertiesForType(int apiLevel) {
201	return propertyDescriptors(apiLevel);
202	}
203
204	@Override
205	final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
206	if (property == BODY_PROPERTY) {
207	if (get) {
208	return getBody();
209	} else {
210	setBody((Block) child);
211	return null;
212	}
213	}
214	if (property == FINALLY_PROPERTY) {
215	if (get) {
216	return getFinally();
217	} else {
218	setFinally((Block) child);
219	return null;
220	}
221	}
222	// allow default implementation to flag the error
223	return super.internalGetSetChildProperty(property, get, child);
224	}
225
226	@Override
227	final List internalGetChildListProperty(ChildListPropertyDescriptor property) {
228	if (property == RESOURCES_PROPERTY \|\| property == RESOURCES2_PROPERTY) {
229	return resources();
230	}
231	if (property == CATCH_CLAUSES_PROPERTY) {
232	return catchClauses();
233	}
234	// allow default implementation to flag the error
235	return super.internalGetChildListProperty(property);
236	}
237
238	@Override
239	final int getNodeType0() {
240	return TRY_STATEMENT;
241	}
242
243	@Override
244	ASTNode clone0(AST target) {
245	TryStatement result = new TryStatement(target);
246	result.setSourceRange(getStartPosition(), getLength());
247	result.copyLeadingComment(this);
248	if (this.ast.apiLevel >= AST.JLS4_INTERNAL) {
249	result.resources().addAll(
250	ASTNode.copySubtrees(target, resources()));
251	}
252	result.setBody((Block) getBody().clone(target));
253	result.catchClauses().addAll(
254	ASTNode.copySubtrees(target, catchClauses()));
255	result.setFinally(
256	(Block) ASTNode.copySubtree(target, getFinally()));
257	return result;
258	}
259
260	@Override
261	final boolean subtreeMatch0(ASTMatcher matcher, Object other) {
262	// dispatch to correct overloaded match method
263	return matcher.match(this, other);
264	}
265
266	@Override
267	void accept0(ASTVisitor visitor) {
268	boolean visitChildren = visitor.visit(this);
269	if (visitChildren) {
270	// visit children in normal left to right reading order
271	if (this.ast.apiLevel >= AST.JLS4_INTERNAL) {
272	acceptChildren(visitor, this.resources);
273	}
274	acceptChild(visitor, getBody());
275	acceptChildren(visitor, this.catchClauses);
276	acceptChild(visitor, getFinally());
277	}
278	visitor.endVisit(this);
279	}
280
281	/**
282	* Returns the body of this try statement.
283	*
284	* @return the try body
285	*/
286	public Block getBody() {
287	if (this.body == null) {
288	// lazy init must be thread-safe for readers
289	synchronized (this) {
290	if (this.body == null) {
291	preLazyInit();
292	this.body = new Block(this.ast);
293	postLazyInit(this.body, BODY_PROPERTY);
294	}
295	}
296	}
297	return this.body;
298	}
299
300	/**
301	* Sets the body of this try statement.
302	*
303	* @param body the block node
304	* @exception IllegalArgumentException if:
305	* <ul>
306	* <li>the node belongs to a different AST</li>
307	* <li>the node already has a parent</li>
308	* <li>a cycle in would be created</li>
309	* </ul>
310	*/
311	public void setBody(Block body) {
312	if (body == null) {
313	throw new IllegalArgumentException();
314	}
315	ASTNode oldChild = this.body;
316	preReplaceChild(oldChild, body, BODY_PROPERTY);
317	this.body = body;
318	postReplaceChild(oldChild, body, BODY_PROPERTY);
319	}
320
321	/**
322	* Returns the live ordered list of catch clauses for this try statement.
323	*
324	* @return the live list of catch clauses
325	* (element type: {@link CatchClause})
326	*/
327	public List catchClauses() {
328	return this.catchClauses;
329	}
330
331	/**
332	* Returns the finally block of this try statement, or <code>null</code> if
333	* this try statement has <b>no</b> finally block.
334	*
335	* @return the finally block, or <code>null</code> if this try statement
336	* has none
337	*/
338	public Block getFinally() {
339	return this.optionalFinallyBody;
340	}
341
342	/**
343	* Sets or clears the finally block of this try statement.
344	*
345	* @param block the finally block node, or <code>null</code> if
346	* there is none
347	* @exception IllegalArgumentException if:
348	* <ul>
349	* <li>the node belongs to a different AST</li>
350	* <li>the node already has a parent</li>
351	* <li>a cycle in would be created</li>
352	* </ul>
353	*/
354	public void setFinally(Block block) {
355	ASTNode oldChild = this.optionalFinallyBody;
356	preReplaceChild(oldChild, block, FINALLY_PROPERTY);
357	this.optionalFinallyBody = block;
358	postReplaceChild(oldChild, block, FINALLY_PROPERTY);
359	}
360
361	/**
362	* Returns the live ordered list of resources for this try statement (added in JLS4 API).
363	*
364	* <p>A resource is either a {@link VariableDeclarationExpression} or (since JLS9) a {@link Name}.</p>
365	*
366	* @return the live list of resources (element type: {@link Expression}).
367	* In the deprecated JLS4 and JLS8 APIs, this used to be
368	* (element type: {@link VariableDeclarationExpression}).
369	* @exception UnsupportedOperationException if this operation is used
370	* in a JLS2 or JLS3 AST
371	* @since 3.7.1
372	*/
373	public List resources() {
374	// more efficient than just calling unsupportedIn2_3() to check
375	if (this.resources == null) {
376	unsupportedIn2_3();
377	}
378	return this.resources;
379	}
380
381	@Override
382	int memSize() {
383	return super.memSize() + 4 * 4;
384	}
385
386	@Override
387	int treeSize() {
388	return
389	memSize()
390	+ (this.resources == null ? 0 : this.resources.listSize())
391	+ (this.body == null ? 0 : getBody().treeSize())
392	+ this.catchClauses.listSize()
393	+ (this.optionalFinallyBody == null ? 0 : getFinally().treeSize());
394	}
395	}
396