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2    * Copyright (c) 2000, 2013, 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
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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).
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17   * You should have received a copy of the GNU General Public License version
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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 CompositeData} 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>&nbsp;
87       * @param  description  The human readable description of the composite type this instance represents;
88       *                      cannot be a null or empty string.
89       * <br>&nbsp;
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>&nbsp;
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 null or an empty string.
101      * <br>&nbsp;
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>&nbsp;
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>&nbsp;
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>&nbsp;
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             for (String key : nameToDescription.keySet()) {
424                 value += key.hashCode();
425                 value += this.nameToType.get(key).hashCode();
426             }
427             myHashCode = Integer.valueOf(value);
428         }
429 
430         // return always the same hash code for this instance (immutable)
431         //
432         return myHashCode.intValue();
433     }
434 
435     /**
436      * Returns a string representation of this <code>CompositeType</code> instance.
437      * <p>
438      * The string representation consists of
439      * the name of this class (ie <code>javax.management.openmbean.CompositeType</code>), the type name for this instance,
440      * and the list of the items names and types string representation of this instance.
441      * <p>
442      * As <code>CompositeType</code> instances are immutable, the string representation for this instance is calculated once,
443      * on the first call to <code>toString</code>, and then the same value is returned for subsequent calls.
444      *
445      * @return  a string representation of this <code>CompositeType</code> instance
446      */
447     public String toString() {
448 
449         // Calculate the string representation if it has not yet been done (ie 1st call to toString())
450         //
451         if (myToString == null) {
452             final StringBuilder result = new StringBuilder();
453             result.append(this.getClass().getName());
454             result.append("(name=");
455             result.append(getTypeName());
456             result.append(",items=(");
457             int i=0;
458             Iterator<String> k=nameToType.keySet().iterator();
459             String key;
460             while (k.hasNext()) {
461                 key = k.next();
462                 if (i > 0) result.append(",");
463                 result.append("(itemName=");
464                 result.append(key);
465                 result.append(",itemType=");
466                 result.append(nameToType.get(key).toString() +")");
467                 i++;
468             }
469             result.append("))");
470             myToString = result.toString();
471         }
472 
473         // return always the same string representation for this instance (immutable)
474         //
475         return myToString;
476     }
477 
478 }