1 /*
2 * Copyright 2000-2007 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26
27 package javax.management.openmbean;
28
29
30 // java import
31 //
32 import java.util.Set;
33 import java.util.TreeMap;
34 import java.util.Collections;
35 import java.util.Iterator;
36
37 // jmx import
38 //
39
40
41 /**
42 * The <code>CompositeType</code> class is the <i>open type</i> class
43 * whose instances describe the types of {@link CompositeData <code>CompositeData</code>} values.
44 *
45 *
46 * @since 1.5
47 */
48 public class CompositeType extends OpenType<CompositeData> {
49
50 /* Serial version */
51 static final long serialVersionUID = -5366242454346948798L;
52
53 /**
54 * @serial Sorted mapping of the item names to their descriptions
55 */
56 private TreeMap<String,String> nameToDescription;
57
58 /**
59 * @serial Sorted mapping of the item names to their open types
60 */
61 private TreeMap<String,OpenType<?>> nameToType;
62
63 /* As this instance is immutable, following three values need only
64 * be calculated once. */
65 private transient Integer myHashCode = null;
66 private transient String myToString = null;
67 private transient Set<String> myNamesSet = null;
68
69
70 /* *** Constructor *** */
71
72 /**
73 * Constructs a <code>CompositeType</code> instance, checking for the validity of the given parameters.
74 * The validity constraints are described below for each parameter.
75 * <p>
76 * Note that the contents of the three array parameters
77 * <var>itemNames</var>, <var>itemDescriptions</var> and <var>itemTypes</var>
78 * are internally copied so that any subsequent modification of these arrays by the caller of this constructor
79 * has no impact on the constructed <code>CompositeType</code> instance.
80 * <p>
81 * The Java class name of composite data values this composite type represents
82 * (ie the class name returned by the {@link OpenType#getClassName() getClassName} method)
83 * is set to the string value returned by <code>CompositeData.class.getName()</code>.
84 * <p>
85 * @param typeName The name given to the composite type this instance represents; cannot be a null or empty string.
86 * <br>
87 * @param description The human readable description of the composite type this instance represents;
88 * cannot be a null or empty string.
89 * <br>
90 * @param itemNames The names of the items contained in the
91 * composite data values described by this <code>CompositeType</code> instance;
92 * cannot be null and should contain at least one element; no element can be a null or empty string.
93 * Note that the order in which the item names are given is not important to differentiate a
94 * <code>CompositeType</code> instance from another;
95 * the item names are internally stored sorted in ascending alphanumeric order.
96 * <br>
97 * @param itemDescriptions The descriptions, in the same order as <var>itemNames</var>, of the items contained in the
98 * composite data values described by this <code>CompositeType</code> instance;
99 * should be of the same size as <var>itemNames</var>;
100 * no element can be a null or empty string.
101 * <br>
102 * @param itemTypes The open type instances, in the same order as <var>itemNames</var>, describing the items contained
103 * in the composite data values described by this <code>CompositeType</code> instance;
104 * should be of the same size as <var>itemNames</var>;
105 * no element can be null.
106 * <br>
107 * @throws IllegalArgumentException If <var>typeName</var> or <var>description</var> is a null or empty string,
108 * or <var>itemNames</var> or <var>itemDescriptions</var> or <var>itemTypes</var> is null,
109 * or any element of <var>itemNames</var> or <var>itemDescriptions</var>
110 * is a null or empty string,
111 * or any element of <var>itemTypes</var> is null,
112 * or <var>itemNames</var> or <var>itemDescriptions</var> or <var>itemTypes</var>
113 * are not of the same size.
114 * <br>
115 * @throws OpenDataException If <var>itemNames</var> contains duplicate item names
116 * (case sensitive, but leading and trailing whitespaces removed).
117 */
118 public CompositeType(String typeName,
119 String description,
120 String[] itemNames,
121 String[] itemDescriptions,
122 OpenType<?>[] itemTypes) throws OpenDataException {
123
124 // Check and construct state defined by parent
125 //
126 super(CompositeData.class.getName(), typeName, description, false);
127
128 // Check the 3 arrays are not null or empty (ie length==0) and that there is no null element or empty string in them
129 //
130 checkForNullElement(itemNames, "itemNames");
131 checkForNullElement(itemDescriptions, "itemDescriptions");
132 checkForNullElement(itemTypes, "itemTypes");
133 checkForEmptyString(itemNames, "itemNames");
134 checkForEmptyString(itemDescriptions, "itemDescriptions");
135
136 // Check the sizes of the 3 arrays are the same
137 //
138 if ( (itemNames.length != itemDescriptions.length) || (itemNames.length != itemTypes.length) ) {
139 throw new IllegalArgumentException("Array arguments itemNames[], itemDescriptions[] and itemTypes[] "+
140 "should be of same length (got "+ itemNames.length +", "+
141 itemDescriptions.length +" and "+ itemTypes.length +").");
142 }
143
144 // Initialize internal "names to descriptions" and "names to types" sorted maps,
145 // and, by doing so, check there are no duplicate item names
146 //
147 nameToDescription = new TreeMap<String,String>();
148 nameToType = new TreeMap<String,OpenType<?>>();
149 String key;
150 for (int i=0; i<itemNames.length; i++) {
151 key = itemNames[i].trim();
152 if (nameToDescription.containsKey(key)) {
153 throw new OpenDataException("Argument's element itemNames["+ i +"]=\""+ itemNames[i] +
154 "\" duplicates a previous item names.");
155 }
156 nameToDescription.put(key, itemDescriptions[i].trim());
157 nameToType.put(key, itemTypes[i]);
158 }
159 }
160
161 private static void checkForNullElement(Object[] arg, String argName) {
162 if ( (arg == null) || (arg.length == 0) ) {
163 throw new IllegalArgumentException("Argument "+ argName +"[] cannot be null or empty.");
164 }
165 for (int i=0; i<arg.length; i++) {
166 if (arg[i] == null) {
167 throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be null.");
168 }
169 }
170 }
171
172 private static void checkForEmptyString(String[] arg, String argName) {
173 for (int i=0; i<arg.length; i++) {
174 if (arg[i].trim().equals("")) {
175 throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be an empty string.");
176 }
177 }
178 }
179
180 /* *** Composite type specific information methods *** */
181
182 /**
183 * Returns <code>true</code> if this <code>CompositeType</code> instance defines an item
184 * whose name is <var>itemName</var>.
185 *
186 * @param itemName the name of the item.
187 *
188 * @return true if an item of this name is present.
189 */
190 public boolean containsKey(String itemName) {
191
192 if (itemName == null) {
193 return false;
194 }
195 return nameToDescription.containsKey(itemName);
196 }
197
198 /**
199 * Returns the description of the item whose name is <var>itemName</var>,
200 * or <code>null</code> if this <code>CompositeType</code> instance does not define any item
201 * whose name is <var>itemName</var>.
202 *
203 * @param itemName the name of the item.
204 *
205 * @return the description.
206 */
207 public String getDescription(String itemName) {
208
209 if (itemName == null) {
210 return null;
211 }
212 return nameToDescription.get(itemName);
213 }
214
215 /**
216 * Returns the <i>open type</i> of the item whose name is <var>itemName</var>,
217 * or <code>null</code> if this <code>CompositeType</code> instance does not define any item
218 * whose name is <var>itemName</var>.
219 *
220 * @param itemName the name of the time.
221 *
222 * @return the type.
223 */
224 public OpenType<?> getType(String itemName) {
225
226 if (itemName == null) {
227 return null;
228 }
229 return (OpenType<?>) nameToType.get(itemName);
230 }
231
232 /**
233 * Returns an unmodifiable Set view of all the item names defined by this <code>CompositeType</code> instance.
234 * The set's iterator will return the item names in ascending order.
235 *
236 * @return a {@link Set} of {@link String}.
237 */
238 public Set<String> keySet() {
239
240 // Initializes myNamesSet on first call
241 if (myNamesSet == null) {
242 myNamesSet = Collections.unmodifiableSet(nameToDescription.keySet());
243 }
244
245 return myNamesSet; // always return the same value
246 }
247
248
249 /**
250 * Tests whether <var>obj</var> is a value which could be
251 * described by this <code>CompositeType</code> instance.
252 *
253 * <p>If <var>obj</var> is null or is not an instance of
254 * <code>javax.management.openmbean.CompositeData</code>,
255 * <code>isValue</code> returns <code>false</code>.</p>
256 *
257 * <p>If <var>obj</var> is an instance of
258 * <code>javax.management.openmbean.CompositeData</code>, then let
259 * {@code ct} be its {@code CompositeType} as returned by {@link
260 * CompositeData#getCompositeType()}. The result is true if
261 * {@code this} is <em>assignable from</em> {@code ct}. This
262 * means that:</p>
263 *
264 * <ul>
265 * <li>{@link #getTypeName() this.getTypeName()} equals
266 * {@code ct.getTypeName()}, and
267 * <li>there are no item names present in {@code this} that are
268 * not also present in {@code ct}, and
269 * <li>for every item in {@code this}, its type is assignable from
270 * the type of the corresponding item in {@code ct}.
271 * </ul>
272 *
273 * <p>A {@code TabularType} is assignable from another {@code
274 * TabularType} if they have the same {@linkplain
275 * TabularType#getTypeName() typeName} and {@linkplain
276 * TabularType#getIndexNames() index name list}, and the
277 * {@linkplain TabularType#getRowType() row type} of the first is
278 * assignable from the row type of the second.
279 *
280 * <p>An {@code ArrayType} is assignable from another {@code
281 * ArrayType} if they have the same {@linkplain
282 * ArrayType#getDimension() dimension}; and both are {@linkplain
283 * ArrayType#isPrimitiveArray() primitive arrays} or neither is;
284 * and the {@linkplain ArrayType#getElementOpenType() element
285 * type} of the first is assignable from the element type of the
286 * second.
287 *
288 * <p>In every other case, an {@code OpenType} is assignable from
289 * another {@code OpenType} only if they are equal.</p>
290 *
291 * <p>These rules mean that extra items can be added to a {@code
292 * CompositeData} without making it invalid for a {@code CompositeType}
293 * that does not have those items.</p>
294 *
295 * @param obj the value whose open type is to be tested for compatibility
296 * with this <code>CompositeType</code> instance.
297 *
298 * @return <code>true</code> if <var>obj</var> is a value for this
299 * composite type, <code>false</code> otherwise.
300 */
301 public boolean isValue(Object obj) {
302
303 // if obj is null or not CompositeData, return false
304 //
305 if (!(obj instanceof CompositeData)) {
306 return false;
307 }
308
309 // if obj is not a CompositeData, return false
310 //
311 CompositeData value = (CompositeData) obj;
312
313 // test value's CompositeType is assignable to this CompositeType instance
314 //
315 CompositeType valueType = value.getCompositeType();
316 return this.isAssignableFrom(valueType);
317 }
318
319 /**
320 * Tests whether values of the given type can be assigned to this
321 * open type. The result is true if the given type is also a
322 * CompositeType with the same name ({@link #getTypeName()}), and
323 * every item in this type is also present in the given type with
324 * the same name and assignable type. There can be additional
325 * items in the given type, which are ignored.
326 *
327 * @param ot the type to be tested.
328 *
329 * @return true if {@code ot} is assignable to this open type.
330 */
331 @Override
332 boolean isAssignableFrom(OpenType ot) {
333 if (!(ot instanceof CompositeType))
334 return false;
335 CompositeType ct = (CompositeType) ot;
336 if (!ct.getTypeName().equals(getTypeName()))
337 return false;
338 for (String key : keySet()) {
339 OpenType<?> otItemType = ct.getType(key);
340 OpenType<?> thisItemType = getType(key);
341 if (otItemType == null ||
342 !thisItemType.isAssignableFrom(otItemType))
343 return false;
344 }
345 return true;
346 }
347
348
349 /* *** Methods overriden from class Object *** */
350
351 /**
352 * Compares the specified <code>obj</code> parameter with this <code>CompositeType</code> instance for equality.
353 * <p>
354 * Two <code>CompositeType</code> instances are equal if and only if all of the following statements are true:
355 * <ul>
356 * <li>their type names are equal</li>
357 * <li>their items' names and types are equal</li>
358 * </ul>
359 * <br>
360 * @param obj the object to be compared for equality with this <code>CompositeType</code> instance;
361 * if <var>obj</var> is <code>null</code>, <code>equals</code> returns <code>false</code>.
362 *
363 * @return <code>true</code> if the specified object is equal to this <code>CompositeType</code> instance.
364 */
365 public boolean equals(Object obj) {
366
367 // if obj is null, return false
368 //
369 if (obj == null) {
370 return false;
371 }
372
373 // if obj is not a CompositeType, return false
374 //
375 CompositeType other;
376 try {
377 other = (CompositeType) obj;
378 } catch (ClassCastException e) {
379 return false;
380 }
381
382 // Now, really test for equality between this CompositeType instance and the other
383 //
384
385 // their names should be equal
386 if ( ! this.getTypeName().equals(other.getTypeName()) ) {
387 return false;
388 }
389
390 // their items names and types should be equal
391 if ( ! this.nameToType.equals(other.nameToType) ) {
392 return false;
393 }
394
395 // All tests for equality were successfull
396 //
397 return true;
398 }
399
400 /**
401 * Returns the hash code value for this <code>CompositeType</code> instance.
402 * <p>
403 * The hash code of a <code>CompositeType</code> instance is the sum of the hash codes
404 * of all elements of information used in <code>equals</code> comparisons
405 * (ie: name, items names, items types).
406 * This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code>
407 * for any two <code>CompositeType</code> instances <code>t1</code> and <code>t2</code>,
408 * as required by the general contract of the method
409 * {@link Object#hashCode() Object.hashCode()}.
410 * <p>
411 * As <code>CompositeType</code> instances are immutable, the hash code for this instance is calculated once,
412 * on the first call to <code>hashCode</code>, and then the same value is returned for subsequent calls.
413 *
414 * @return the hash code value for this <code>CompositeType</code> instance
415 */
416 public int hashCode() {
417
418 // Calculate the hash code value if it has not yet been done (ie 1st call to hashCode())
419 //
420 if (myHashCode == null) {
421 int value = 0;
422 value += this.getTypeName().hashCode();
423 String key;
424 for (Iterator k = nameToDescription.keySet().iterator(); k.hasNext(); ) {
425 key = (String) k.next();
426 value += key.hashCode();
427 value += this.nameToType.get(key).hashCode();
428 }
429 myHashCode = Integer.valueOf(value);
430 }
431
432 // return always the same hash code for this instance (immutable)
433 //
434 return myHashCode.intValue();
435 }
436
437 /**
438 * Returns a string representation of this <code>CompositeType</code> instance.
439 * <p>
440 * The string representation consists of
441 * the name of this class (ie <code>javax.management.openmbean.CompositeType</code>), the type name for this instance,
442 * and the list of the items names and types string representation of this instance.
443 * <p>
444 * As <code>CompositeType</code> instances are immutable, the string representation for this instance is calculated once,
445 * on the first call to <code>toString</code>, and then the same value is returned for subsequent calls.
446 *
447 * @return a string representation of this <code>CompositeType</code> instance
448 */
449 public String toString() {
450
451 // Calculate the string representation if it has not yet been done (ie 1st call to toString())
452 //
453 if (myToString == null) {
454 final StringBuilder result = new StringBuilder();
455 result.append(this.getClass().getName());
456 result.append("(name=");
457 result.append(getTypeName());
458 result.append(",items=(");
459 int i=0;
460 Iterator k=nameToType.keySet().iterator();
461 String key;
462 while (k.hasNext()) {
463 key = (String) k.next();
464 if (i > 0) result.append(",");
465 result.append("(itemName=");
466 result.append(key);
467 result.append(",itemType=");
468 result.append(nameToType.get(key).toString() +")");
469 i++;
470 }
471 result.append("))");
472 myToString = result.toString();
473 }
474
475 // return always the same string representation for this instance (immutable)
476 //
477 return myToString;
478 }
479
480 }
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