CompositeDataSupport


1   /*
2    * @(#)CompositeDataSupport.java    3.27 04/03/24
3    * 
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   
9   package javax.management.openmbean;
10  
11  
12  // java import
13  //
14  import java.io.Serializable  ;
15  import java.util.Set  ;
16  import java.util.Map  ;
17  import java.util.SortedMap  ;
18  import java.util.TreeMap  ;
19  import java.util.Collection  ;
20  import java.util.Collections  ;
21  import java.util.Iterator  ;
22  import java.util.Arrays  ;
23  
24  
25  // jmx import
26  //
27  
28  
29  /**
30   * The <tt>CompositeDataSupport</tt> class is the <i>open data</i> class which implements the <tt>CompositeData</tt> interface.
31   *
32   * @version     3.27  04/03/24
33   * @author      Sun Microsystems, Inc.
34   *
35   * @since 1.5
36   * @since.unbundled JMX 1.1
37   */
38  public class CompositeDataSupport 
39      implements CompositeData  , Serializable   {
40  
41      /* Serial version */
42      static final long serialVersionUID = 8003518976613702244L;
43  
44      /**
45       * @serial Internal representation of the mapping of item names to their respective values.
46       *         A {@link SortedMap} is used for faster retrieval of elements.
47       */
48      private SortedMap   contents = new TreeMap  ();
49  
50      /**
51       * @serial The <i>composite type </i> of this <i>composite data</i> instance.
52       */
53      private CompositeType   compositeType;
54      
55  
56  
57      /**
58       * <p>
59       * Constructs a <tt>CompositeDataSupport</tt> instance with the specified <tt>compositeType</tt>, whose item values
60       * are specified by <tt>itemValues[]</tt>, in the same order as in <tt>itemNames[]</tt>. 
61       * As a <tt>CompositeType</tt> does not specify any order on its items, the <tt>itemNames[]</tt> parameter is used
62       * to specify the order in which the values are given in <tt>itemValues[]</tt>. 
63       * The items contained in this <tt>CompositeDataSupport</tt> instance are internally stored in a <tt>TreeMap</tt>,
64       * thus sorted in ascending lexicographic order of their names, for faster retrieval of individual item values.
65       * <p>
66       * The constructor checks that all the constraints listed below for each parameter are satisfied,
67       * and throws the appropriate exception if they are not.
68       * <p>
69       * @param  compositeType  the <i>composite type </i> of this <i>composite data</i> instance;
70       *                must not be null.
71       * <p>
72       * @param  itemNames  <tt>itemNames</tt> must list, in any order, all the item names defined in <tt>compositeType</tt>;
73       *            the order in which the names are listed, is used to match values in <tt>itemValues[]</tt>;
74       *            must not be null or empty. 
75       * <p>
76       * @param  itemValues  the values of the items, listed in the same order as their respective names in <tt>itemNames</tt>;
77       *             each item value can be null, but if it is non-null it must be 
78       *             a valid value for the open type defined in <tt>compositeType</tt> for the corresponding item;
79       *             must be of the same size as <tt>itemNames</tt>; must not be null or empty.
80       * <p>
81       * @throws  IllegalArgumentException  <tt>compositeType</tt> is null, or <tt>itemNames[]</tt> or <tt>itemValues[]</tt> is null or empty,
82       *                    or one of the elements in <tt>itemNames[]</tt>  is a null or empty string,
83       *                    or <tt>itemNames[]</tt> and <tt>itemValues[]</tt> are not of the same size.
84       * <p>
85       * @throws  OpenDataException  <tt>itemNames[]</tt> or <tt>itemValues[]</tt>'s size differs from 
86       *                 the number of items defined in <tt>compositeType</tt>,
87       *                 or one of the elements in <tt>itemNames[]</tt> does not exist as an item name defined in <tt>compositeType</tt>,
88       *                 or one of the elements in <tt>itemValues[]</tt> is not a valid value for the corresponding item 
89       *                 as defined in <tt>compositeType</tt>.
90       * <p>
91       */
92      public CompositeDataSupport(CompositeType   compositeType, String  [] itemNames, Object  [] itemValues)
93      throws OpenDataException   {
94  
95      // Check compositeType is not null 
96      //
97      if (compositeType == null) {
98          throw new IllegalArgumentException  ("Argument compositeType cannot be null.");
99      }
100 
101     // item names defined in compositeType:
102     Set   namesSet = compositeType.keySet();
103 
104     // Check the array itemNames is not null or empty (length!=0) and 
105     // that there is no null element or empty string in it
106     //
107     checkForNullElement(itemNames, "itemNames");
108     checkForEmptyString(itemNames, "itemNames");
109 
110     // Check the array itemValues is not null or empty (length!=0)
111     // (NOTE: we allow null values as array elements) 
112     //
113     if ( (itemValues == null) || (itemValues.length == 0) ) {
114         throw new IllegalArgumentException  ("Argument itemValues[] cannot be null or empty.");
115     }
116 
117     // Check that the sizes of the 2 arrays itemNames and itemValues are the same
118     //
119     if (itemNames.length != itemValues.length) {
120         throw new IllegalArgumentException  ("Array arguments itemNames[] and itemValues[] "+
121                            "should be of same length (got "+ itemNames.length +
122                            " and "+ itemValues.length +").");
123     }
124     
125     // Check the size of the 2 arrays is equal to the number of items defined in compositeType
126     //
127     if (itemNames.length != namesSet.size()) {
128         throw new OpenDataException  ("The size of array arguments itemNames[] and itemValues[] should be equal to the number of items defined"+
129                     " in argument compositeType (found "+ itemNames.length +" elements in itemNames[] and itemValues[],"+
130                     " expecting "+ namesSet.size() +" elements according to compositeType.");
131     }
132 
133     // Check parameter itemNames[] contains all names defined in the compositeType of this instance
134     //
135     if ( ! Arrays.asList(itemNames).containsAll(namesSet) ) {
136         throw new OpenDataException  ("Argument itemNames[] does not contain all names defined in the compositeType of this instance.");
137     }
138     
139     // Check each element of itemValues[], if not null, is of the open type defined for the corresponding item
140     //
141     OpenType   itemType;
142     for (int i=0; i<itemValues.length; i++) {
143         itemType = compositeType.getType(itemNames[i]);
144         if ( (itemValues[i] != null) && (! itemType.isValue(itemValues[i])) ) {
145         throw new OpenDataException  ("Argument's element itemValues["+ i +"]=\""+ itemValues[i] +"\" is not a valid value for"+
146                         " this item (itemName="+ itemNames[i] +",itemType="+ itemType +").");
147         }
148     }
149     
150     // Initialize internal fields: compositeType and contents 
151     //
152     this.compositeType = compositeType;
153     for (int i=0; i<itemNames.length; i++) {
154         this.contents.put(itemNames[i], itemValues[i]);
155     }
156     }
157 
158     /**
159      * <p>
160      * Constructs a <tt>CompositeDataSupport</tt> instance with the specified <tt>compositeType</tt>, whose item names and corresponding values
161      * are given by the mappings in the map <tt>items</tt>.
162      * This constructor converts the keys to a string array and the values to an object array and calls
163      * <tt>CompositeDataSupport(javax.management.openmbean.CompositeType, java.lang.String[], java.lang.Object[])</tt>.
164      * <p>
165      * @param  compositeType  the <i>composite type </i> of this <i>composite data</i> instance;
166      *                must not be null.
167      * <p>
168      * @param  items  the mappings of all the item names to their values;
169      *            <tt>items</tt> must contain all the item names defined in <tt>compositeType</tt>;
170      *            must not be null or empty. 
171      * <p>
172      * @throws  IllegalArgumentException  <tt>compositeType</tt> is null, or <tt>items</tt> is null or empty,
173      *                    or one of the keys in <tt>items</tt>  is a null or empty string,
174      *                    or one of the values in <tt>items</tt>  is null.
175      * <p>
176      * @throws  OpenDataException  <tt>items</tt>' size differs from the number of items defined in <tt>compositeType</tt>,
177      *                 or one of the keys in <tt>items</tt> does not exist as an item name defined in <tt>compositeType</tt>,
178      *                 or one of the values in <tt>items</tt> is not a valid value for the corresponding item 
179      *                 as defined in <tt>compositeType</tt>.
180      * <p>
181      * @throws ArrayStoreException  one or more keys in <tt>items</tt> is not of the class <tt>java.lang.String</tt>.
182      * <p>
183      */
184     public CompositeDataSupport(CompositeType   compositeType, Map   items)
185     throws OpenDataException   {
186 
187 
188     // Let the other constructor do the job, as the call to another constructor must be the first call
189     //
190     this( compositeType, 
191           (items==null  ?  null  :  (String  []) items.keySet().toArray(new String  [items.size()])), // may raise an ArrayStoreException
192           (items==null  ?  null  :  items.values().toArray()) );
193     }
194 
195     /**
196      *
197      */
198     private static void checkForNullElement(Object  [] arg, String   argName) {
199     if ( (arg == null) || (arg.length == 0) ) {
200         throw new IllegalArgumentException  ("Argument "+ argName +"[] cannot be null or empty.");
201     }
202     for (int i=0; i<arg.length; i++) {
203         if (arg[i] == null) {
204         throw new IllegalArgumentException  ("Argument's element "+ argName +"["+ i +"] cannot be null.");
205         }
206     }
207     }
208 
209     /**
210      *
211      */
212     private static void checkForEmptyString(String  [] arg, String   argName) {
213     for (int i=0; i<arg.length; i++) {
214         if (arg[i].trim().equals("")) {
215         throw new IllegalArgumentException  ("Argument's element "+ argName +"["+ i +"] cannot be an empty string.");
216         }
217     }
218     }
219 
220     /**
221      * Returns the <i>composite type </i> of this <i>composite data</i> instance.
222      */
223     public CompositeType   getCompositeType() {
224 
225     return compositeType;
226     }
227 
228     /**
229      * Returns the value of the item whose name is <tt>key</tt>.
230      *
231      * @throws IllegalArgumentException  if <tt>key</tt> is a null or empty String.
232      *
233      * @throws InvalidKeyException  if <tt>key</tt> is not an existing item name for this <tt>CompositeData</tt> instance.
234      */
235     public Object   get(String   key) {
236 
237     if ( (key == null) || (key.trim().equals("")) ) {
238         throw new IllegalArgumentException  ("Argument key cannot be a null or empty String.");
239     }
240     if ( ! contents.containsKey(key.trim())) {
241         throw new InvalidKeyException  ("Argument key=\""+ key.trim() +"\" is not an existing item name for this CompositeData instance.");
242     }
243     return contents.get(key.trim());
244     }
245 
246     /**
247      * Returns an array of the values of the items whose names are specified by <tt>keys</tt>, in the same order as <tt>keys</tt>.
248      *
249      * @throws IllegalArgumentException  if an element in <tt>keys</tt> is a null or empty String.
250      *
251      * @throws InvalidKeyException  if an element in <tt>keys</tt> is not an existing item name for this <tt>CompositeData</tt> instance.
252      */
253     public Object  [] getAll(String  [] keys) {
254 
255     if ( (keys == null) || (keys.length == 0) ) {
256         return new Object  [0];
257     }
258     Object  [] results = new Object  [keys.length];
259     for (int i=0; i<keys.length; i++) {
260         results[i] = this.get(keys[i]);
261     }
262     return results;
263     }
264 
265     /**
266      * Returns <tt>true</tt> if and only if this <tt>CompositeData</tt> instance contains 
267      * an item whose name is <tt>key</tt>. 
268      * If <tt>key</tt> is a null or empty String, this method simply returns false.
269      */
270     public boolean containsKey(String   key) { 
271 
272     if ( (key == null) || (key.trim().equals("")) ) {
273         return false;
274     }
275     return contents.containsKey(key);
276     }
277 
278     /**
279      * Returns <tt>true</tt> if and only if this <tt>CompositeData</tt> instance contains an item 
280      * whose value is <tt>value</tt>.
281      */
282     public boolean containsValue(Object   value) { 
283 
284     return contents.containsValue(value);
285     }
286 
287     /**
288      * Returns an unmodifiable Collection view of the item values contained in this <tt>CompositeData</tt> instance.
289      * The returned collection's iterator will return the values in the ascending lexicographic order of the corresponding 
290      * item names. 
291      */
292     public Collection   values() { 
293 
294     return Collections.unmodifiableCollection(contents.values());
295     }
296 
297     /**
298      * Compares the specified <var>obj</var> parameter with this <code>CompositeDataSupport</code> instance for equality. 
299      * <p>
300      * Returns <tt>true</tt> if and only if all of the following statements are true:
301      * <ul>
302      * <li><var>obj</var> is non null,</li>
303      * <li><var>obj</var> also implements the <code>CompositeData</code> interface,</li>
304      * <li>their composite types are equal</li>
305      * <li>their contents, i.e. (name, value) pairs are equal. </li>
306      * </ul>
307      * This ensures that this <tt>equals</tt> method works properly for <var>obj</var> parameters which are
308      * different implementations of the <code>CompositeData</code> interface, with the restrictions mentioned in the
309      * {@link java.util.Collection#equals(Object) equals}
310      * method of the <tt>java.util.Collection</tt> interface.
311      * <br>&nbsp;
312      * @param  obj  the object to be compared for equality with this <code>CompositeDataSupport</code> instance;
313      * 
314      * @return  <code>true</code> if the specified object is equal to this <code>CompositeDataSupport</code> instance.
315      */
316     public boolean equals(Object   obj) { 
317 
318     // if obj is null, return false
319     //
320     if (obj == null) {
321         return false;
322     }
323 
324     // if obj is not a CompositeData, return false
325     //
326     CompositeData   other;
327     try {
328         other = (CompositeData  ) obj;
329     } catch (ClassCastException   e) {
330         return false;
331     }
332 
333     // their compositeType should be equal
334     if ( ! this.getCompositeType().equals(other.getCompositeType()) ) {
335         return false;
336     }
337     
338     
339         // Currently this test returns false if we have different Array instances with same contents.
340         // Array objects are equals only if their references are equal, ie they are the same object!
341         // CompositeData equals() method need to be modified to compare Array contents... 
342 
343     // their content, i.e. (name, value) pairs, should be equal
344     Map.Entry   entry;
345     boolean ok;
346     for (Iterator   iter = contents.entrySet().iterator(); iter.hasNext();  ) {
347         entry = (Map.Entry  ) iter.next();
348         ok = ( entry.getValue() == null ?
349            other.get((String  )entry.getKey()) == null :
350            entry.getValue().equals(other.get((String  )entry.getKey())) );
351         if ( ! ok ) { 
352         return false;
353         }
354     }
355        
356     // All tests for equality were successfull
357     //
358     return true;
359     }
360 
361     /**
362      * Returns the hash code value for this <code>CompositeDataSupport</code> instance. 
363      * <p>
364      * The hash code of a <code>CompositeDataSupport</code> instance is the sum of the hash codes
365      * of all elements of information used in <code>equals</code> comparisons 
366      * (ie: its <i>composite type</i> and all the item values). 
367      * <p>
368      * This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code> 
369      * for any two <code>CompositeDataSupport</code> instances <code>t1</code> and <code>t2</code>, 
370      * as required by the general contract of the method
371      * {@link Object#hashCode() Object.hashCode()}.
372      * <p>
373      * However, note that another instance of a class implementing the <code>CompositeData</code> interface
374      * may be equal to this <code>CompositeDataSupport</code> instance as defined by {@link #equals}, 
375      * but may have a different hash code if it is calculated differently.
376      *
377      * @return  the hash code value for this <code>CompositeDataSupport</code> instance
378      */
379     public int hashCode() { 
380 
381     int result = 0;
382     result += compositeType.hashCode();
383     Map.Entry   entry;
384     for (Iterator   iter = contents.entrySet().iterator(); iter.hasNext();  ) {
385         entry = (Map.Entry  ) iter.next();
386         result += ( entry.getValue() == null ?  0 :  entry.getValue().hashCode() );
387     }
388     return result;
389     }
390 
391     /**
392      * Returns a string representation of this <code>CompositeDataSupport</code> instance. 
393      * <p>
394      * The string representation consists of the name of this class (ie <code>javax.management.openmbean.CompositeDataSupport</code>), 
395      * the string representation of the composite type of this instance, and the string representation of the contents
396      * (ie list the itemName=itemValue mappings).
397      * 
398      * @return  a string representation of this <code>CompositeDataSupport</code> instance
399      */
400     public String   toString() { 
401 
402     return new StringBuffer  ()
403         .append(this.getClass().getName())
404         .append("(compositeType=")
405         .append(compositeType.toString())
406         .append(",contents=")
407         .append(contents.toString())
408         .append(")")
409         .toString();
410     }
411 
412 }
413
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