001    /* OpenMBeanAttributeInfoSupport.java -- Open typed info about an attribute.
002       Copyright (C) 2006, 2007 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package javax.management.openmbean;
039    
040    import java.util.Collections;
041    import java.util.HashSet;
042    import java.util.Set;
043    
044    import javax.management.MBeanAttributeInfo;
045    
046    /**
047     * Describes an attribute of an open management bean.
048     *
049     * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
050     * @since 1.5
051     */
052    public class OpenMBeanAttributeInfoSupport
053      extends MBeanAttributeInfo
054      implements OpenMBeanAttributeInfo
055    {
056    
057      /**
058       * Compatible with JDK 1.5
059       */
060      private static final long serialVersionUID = -4867215622149721849L;
061    
062      /**
063       * The open type of the attribute.
064       */
065      private OpenType<?> openType;
066    
067      /**
068       * The default value of the attribute (may be <code>null</code>).
069       */
070      private Object defaultValue;
071    
072      /**
073       * The possible legal values of the attribute (may be <code>null</code>).
074       */
075      private Set<?> legalValues;
076    
077      /**
078       * The minimum value of the attribute (may be <code>null</code>).
079       */
080      private Comparable<?> minValue;
081    
082      /**
083       * The maximum value of the attribute (may be <code>null</code>).
084       */
085      private Comparable<?> maxValue;
086    
087      /**
088       * The hash code of this instance.
089       */
090      private transient Integer hashCode;
091    
092      /**
093       * The <code>toString()</code> result of this instance.
094       */
095      private transient String string;
096    
097      /**
098       * Constructs a new {@link OpenMBeanAttributeInfo} using the
099       * specified name, description, open type and access properties.
100       * The name, description and open type may not be <code>null</code>
101       * and the name and description may not be equal to the empty
102       * string.
103       *
104       * @param name the name of the attribute.
105       * @param desc a description of the attribute.
106       * @param type the open type of the attribute.
107       * @param isReadable true if the attribute's value can be read.
108       * @param isWritable true if the attribute's value can be changed.
109       * @param isIs true if the attribute uses an accessor of the form isXXX.
110       * @throws IllegalArgumentException if the name, description or
111       *                                  open type are <code>null</code>
112       *                                  or the name or description are
113       *                                  the empty string.
114       */
115      public OpenMBeanAttributeInfoSupport(String name, String desc, OpenType<?> type,
116                                           boolean isReadable, boolean isWritable,
117                                           boolean isIs)
118      {
119        super(name, type == null ? null : type.getClassName(), desc, isReadable,
120              isWritable, isIs);
121        if (name == null)
122          throw new IllegalArgumentException("The name may not be null.");
123        if (desc == null)
124          throw new IllegalArgumentException("The description may not be null.");
125        if (type == null)
126          throw new IllegalArgumentException("The type may not be null.");
127        if (name.length() == 0)
128          throw new IllegalArgumentException("The name may not be the empty string.");
129        if (desc.length() == 0)
130          throw new IllegalArgumentException("The description may not be the " +
131                                             "empty string.");
132      }
133    
134      /**
135       * Constructs a new {@link OpenMBeanAttributeInfo} using the
136       * specified name, description, open type and default value.  The
137       * name, description and open type cannot be <code>null</code> and
138       * the name and description may not be equal to the empty string.
139       * The default value may be <code>null</code>.  If non-null, it must
140       * be a valid value of the given open type.  Default values are not
141       * applicable to the open types, {@link ArrayType} and {@link
142       * TabularType}.
143       *
144       * @param name the name of the attribute.
145       * @param desc a description of the attribute.
146       * @param type the open type of the attribute.
147       * @param isReadable true if the attribute's value can be read.
148       * @param isWritable true if the attribute's value can be changed.
149       * @param isIs true if the attribute uses an accessor of the form isXXX.
150       * @param defaultValue the default value of the attribute.
151       * @throws IllegalArgumentException if the name, description or
152       *                                  open type are <code>null</code>
153       *                                  or the name or description are
154       *                                  the empty string.
155       * @throws OpenDataException if <code>defaultValue<code> is non-null
156       *                           and is either not a value of the given
157       *                           open type or the open type is an instance
158       *                           of {@link ArrayType} or {@link TabularType}.
159       */
160      public <T> OpenMBeanAttributeInfoSupport(String name, String desc, OpenType<T> type,
161                                               boolean isReadable, boolean isWritable,
162                                               boolean isIs, T defaultValue)
163        throws OpenDataException
164      {
165        this(name, desc, type, isReadable, isWritable, isIs, defaultValue, null);
166      }
167    
168      /**
169       * <p>
170       * Constructs a new {@link OpenMBeanAttributeInfo} using the
171       * specified name, description, open type, access properties,
172       * default, maximum and minimum values.  The name, description
173       * and open type cannot be <code>null</code> and the name and
174       * description may not be equal to the empty string.  The
175       * default, maximum and minimum values may be <code>null</code>.
176       * The following conditions apply when the attributes mentioned
177       * are non-null:
178       * </p>
179       * <ul>
180       * <li>The values must be valid values for the given open type.</li>
181       * <li>Default values are not applicable to the open types, {@link
182       * ArrayType} and {@link TabularType}.</li>
183       * <li>The minimum value must be smaller than or equal to the maximum value
184       * (literally, <code>minValue.compareTo(maxValue) <= 0</code>.</li>
185       * <li>The minimum value must be smaller than or equal to the default value
186       * (literally, <code>minValue.compareTo(defaultValue) <= 0</code>.</li>
187       * <li>The default value must be smaller than or equal to the maximum value
188       * (literally, <code>defaultValue.compareTo(maxValue) <= 0</code>.</li>
189       * </ul>
190       *
191       * @param name the name of the attribute.
192       * @param desc a description of the attribute.
193       * @param type the open type of the attribute.
194       * @param isReadable true if the attribute's value can be read.
195       * @param isWritable true if the attribute's value can be changed.
196       * @param isIs true if the attribute uses an accessor of the form isXXX.
197       * @param defaultValue the default value of the attribute, or <code>null</code>.
198       * @param minimumValue the minimum value of the attribute, or <code>null</code>.
199       * @param maximumValue the maximum value of the attribute, or <code>null</code>.
200       * @throws IllegalArgumentException if the name, description or
201       *                                  open type are <code>null</code>
202       *                                  or the name or description are
203       *                                  the empty string.
204       * @throws OpenDataException if any condition in the list above is broken.
205       */
206      @SuppressWarnings("unchecked")
207      public <T> OpenMBeanAttributeInfoSupport(String name, String desc, OpenType<T> type,
208                                               boolean isReadable, boolean isWritable,
209                                               boolean isIs, T defaultValue,
210                                               Comparable<T> minimumValue,
211                                               Comparable<T> maximumValue)
212        throws OpenDataException
213      {
214        this(name, desc, type, isReadable, isWritable, isIs);
215        if (defaultValue != null && !(type.isValue(defaultValue)))
216          throw new OpenDataException("The default value is not a member of the " +
217                                      "open type given.");
218        if (minimumValue != null && !(type.isValue(minimumValue)))
219          throw new OpenDataException("The minimum value is not a member of the " +
220                                      "open type given.");
221        if (maximumValue != null && !(type.isValue(maximumValue)))
222          throw new OpenDataException("The maximum value is not a member of the " +
223                                      "open type given.");
224        if (defaultValue != null && (type instanceof ArrayType ||
225                                     type instanceof TabularType))
226          throw new OpenDataException("Default values are not applicable for " +
227                                      "array or tabular types.");
228        if (minimumValue != null && maximumValue != null
229            && minimumValue.compareTo((T) maximumValue) > 0)
230          throw new OpenDataException("The minimum value is greater than the " +
231                                      "maximum.");
232        if (minimumValue != null && defaultValue != null
233            && minimumValue.compareTo(defaultValue) > 0)
234          throw new OpenDataException("The minimum value is greater than the " +
235                                      "default.");
236        if (defaultValue != null && maximumValue != null
237            && maximumValue.compareTo(defaultValue) < 0)
238          throw new OpenDataException("The default value is greater than the " +
239                                      "maximum.");
240    
241        openType = type;
242        this.defaultValue = defaultValue;
243        minValue = minimumValue;
244        maxValue = maximumValue;
245      }
246    
247      /**
248       * <p>
249       * Constructs a new {@link OpenMBeanAttributeInfo} using the
250       * specified name, description, open type, access properties, default
251       * value and set of legal values.  The name, description and open type
252       * cannot be <code>null</code> and the name and description may not be
253       * equal to the empty string.  The default, maximum and minimum values
254       * may be <code>null</code>.  The following conditions apply when the
255       * attributes mentioned are non-null:
256       * </p>
257       * <ul>
258       * <li>The default value and each of the legal values must be a valid
259       * value for the given open type.</li>
260       * <li>Default and legal values are not applicable to the open types, {@link
261       * ArrayType} and {@link TabularType}.</li>
262       * <li>The default value is not in the set of legal values.</li>
263       * </ul>
264       * <p>
265       * The legal values are copied from the array into a unmodifiable set,
266       * so future modifications to the array have no effect.
267       * </p>
268       *
269       * @param name the name of the attribute.
270       * @param desc a description of the attribute.
271       * @param type the open type of the attribute.
272       * @param isReadable true if the attribute's value can be read.
273       * @param isWritable true if the attribute's value can be changed.
274       * @param isIs true if the attribute uses an accessor of the form isXXX.
275       * @param defaultValue the default value of the attribute, or <code>null</code>.
276       * @param legalValues the legal values of the attribute.  May be
277       *                    <code>null</code> or an empty array.
278       * @throws IllegalArgumentException if the name, description or
279       *                                  open type are <code>null</code>
280       *                                  or the name or description are
281       *                                  the empty string.
282       * @throws OpenDataException if any condition in the list above is broken.
283       */
284      public <T> OpenMBeanAttributeInfoSupport(String name, String desc, OpenType<T> type,
285                                               boolean isReadable, boolean isWritable,
286                                               boolean isIs, T defaultValue,
287                                               T[] legalValues)
288        throws OpenDataException
289      {
290        this(name, desc, type, isReadable, isWritable, isIs);
291        if (defaultValue != null && !(type.isValue(defaultValue)))
292          throw new OpenDataException("The default value is not a member of the " +
293                                      "open type given.");
294        if (defaultValue != null && (type instanceof ArrayType ||
295                                     type instanceof TabularType))
296          throw new OpenDataException("Default values are not applicable for " +
297                                      "array or tabular types.");
298        if (legalValues != null && (type instanceof ArrayType ||
299                                    type instanceof TabularType))
300          throw new OpenDataException("Legal values are not applicable for " +
301                                      "array or tabular types.");
302        if (legalValues != null && legalValues.length > 0)
303          {
304            Set<T> lv = new HashSet<T>(legalValues.length);
305            for (int a = 0; a < legalValues.length; ++a)
306              {
307                if (legalValues[a] != null &&
308                    !(type.isValue(legalValues[a])))
309                  throw new OpenDataException("The legal value, "
310                                              + legalValues[a] +
311                                              "is not a member of the " +
312                                              "open type given.");
313                lv.add(legalValues[a]);
314              }
315            if (defaultValue != null && !(lv.contains(defaultValue)))
316              throw new OpenDataException("The default value is not in the set " +
317                                          "of legal values.");
318            this.legalValues = Collections.unmodifiableSet(lv);
319          }
320        openType = type;
321        this.defaultValue = defaultValue;
322      }
323    
324      /**
325       * Compares this attribute with the supplied object.  This returns
326       * true iff the object is an instance of {@link OpenMBeanAttributeInfo}
327       * with an equal name and open type and the same default, minimum,
328       * maximum and legal values and the same access properties.
329       *
330       * @param obj the object to compare.
331       * @return true if the object is a {@link OpenMBeanAttributeInfo}
332       *         instance,
333       *         <code>name.equals(object.getName())</code>,
334       *         <code>openType.equals(object.getOpenType())</code>,
335       *         <code>isRead == object.isReadable()</code>,
336       *         <code>isWrite == object.isWritable()</code>,
337       *         <code>isIs == object.isIs()</code>,
338       *         <code>defaultValue.equals(object.getDefaultValue())</code>,
339       *         <code>minValue.equals(object.getMinValue())</code>,
340       *         <code>maxValue.equals(object.getMaxValue())</code>,
341       *         and <code>legalValues.equals(object.getLegalValues())</code>.
342       */
343      public boolean equals(Object obj)
344      {
345        if (!(obj instanceof OpenMBeanAttributeInfo))
346          return false;
347        OpenMBeanAttributeInfo o = (OpenMBeanAttributeInfo) obj;
348        return getName().equals(o.getName()) &&
349          openType.equals(o.getOpenType()) &&
350          isReadable() == o.isReadable() &&
351          isWritable() == o.isWritable() &&
352          isIs() == o.isIs() &&
353          (defaultValue == null ? o.getDefaultValue() == null :
354           defaultValue.equals(o.getDefaultValue())) &&
355          (minValue == null ? o.getMinValue() == null :
356           minValue.equals(o.getMinValue())) &&
357          (maxValue == null ? o.getMaxValue() == null :
358           maxValue.equals(o.getMaxValue())) &&
359          (legalValues == null ? o.getLegalValues() == null :
360           legalValues.equals(o.getLegalValues()));
361      }
362    
363      /**
364       * Returns the default value of this attribute, or <code>null</code>
365       * if there is no default value.
366       *
367       * @return the default value of the attribute, or <code>null</code>
368       *         if there is no default.
369       */
370      public Object getDefaultValue()
371      {
372        return defaultValue;
373      }
374    
375      /**
376       * Returns a {@link java.util.Set} enumerating the legal values
377       * of this attribute, or <code>null</code> if no such limited
378       * set exists for this attribute.
379       *
380       * @return a set of legal values, or <code>null</code> if no such
381       *         set exists.
382       */
383      public Set<?> getLegalValues()
384      {
385        return legalValues;
386      }
387    
388      /**
389       * Returns the maximum value of this attribute, or <code>null</code>
390       * if there is no maximum.
391       *
392       * @return the maximum value, or <code>null</code> if none exists.
393       */
394      public Comparable<?> getMaxValue()
395      {
396        return maxValue;
397      }
398    
399      /**
400       * Returns the minimum value of this attribute, or <code>null</code>
401       * if there is no minimum.
402       *
403       * @return the minimum value, or <code>null</code> if none exists.
404       */
405      public Comparable<?> getMinValue()
406      {
407        return minValue;
408      }
409    
410      /**
411       * Returns the open type instance which represents the type of this
412       * attribute.
413       *
414       * @return the open type of this attribute.
415       */
416      public OpenType<?> getOpenType()
417      {
418        return openType;
419      }
420    
421      /**
422       * Returns true if this attribute has a default value
423       * (i.e. the value is non-null).
424       *
425       * @return true if this attribute has a default.
426       */
427      public boolean hasDefaultValue()
428      {
429        return defaultValue != null;
430      }
431    
432      /**
433       * <p>
434       * Returns the hashcode of the attribute information as the sum of
435       * the hashcodes of the name, open type, default value, maximum
436       * value, minimum value and the set of legal values.
437       * </p>
438       * <p>
439       * As instances of this class are immutable, the hash code
440       * is computed just once for each instance and reused
441       * throughout its life.
442       * </p>
443       *
444       * @return the hashcode of the attribute information.
445       */
446      public int hashCode()
447      {
448        if (hashCode == null)
449          hashCode = Integer.valueOf(getName().hashCode() +
450                                     openType.hashCode() +
451                                     Boolean.valueOf(isReadable()).hashCode() +
452                                     (2 *
453                                      Boolean.valueOf(isWritable()).hashCode()) +
454                                     (4 * Boolean.valueOf(isIs()).hashCode()) +
455                                     (defaultValue == null ? 0 :
456                                      defaultValue.hashCode()) +
457                                     (minValue == null ? 0 :
458                                      minValue.hashCode()) +
459                                     (maxValue == null ? 0 :
460                                      maxValue.hashCode()) +
461                                     (legalValues == null ? 0 :
462                                      legalValues.hashCode()));
463        return hashCode.intValue();
464      }
465    
466      /**
467       * Returns true if there is a set of legal values for this
468       * attribute (i.e. the value is non-null).
469       *
470       * @return true if a set of legal values exists for this
471       *         attribute.
472       */
473      public boolean hasLegalValues()
474      {
475        return legalValues != null;
476      }
477    
478      /**
479       * Returns true if there is a maximum value for this attribute
480       * (i.e. the value is non-null).
481       *
482       * @return true if a maximum value exists for this attribute.
483       */
484      public boolean hasMaxValue()
485      {
486        return maxValue != null;
487      }
488    
489      /**
490       * Returns true if there is a minimum value for this attribute.
491       * (i.e. the value is non-null).
492       *
493       * @return true if a minimum value exists for this attribute.
494       */
495      public boolean hasMinValue()
496      {
497        return minValue != null;
498      }
499    
500      /**
501       * Returns true if the specified object is a valid value for
502       * this attribute.
503       *
504       * @param obj the object to test.
505       * @return true if <code>obj</code> is a valid value for this
506       *         attribute.
507       */
508      public boolean isValue(Object obj)
509      {
510        return openType.isValue(obj);
511      }
512    
513      /**
514       * <p>
515       * Returns a textual representation of this instance.  This
516       * is constructed using the class name
517       * (<code>javax.management.openmbean.OpenMBeanAttributeInfo</code>)
518       * along with the name, open type, access properties, default,
519       * minimum, maximum  and legal values of the attribute.
520       * </p>
521       * <p>
522       * As instances of this class are immutable, the return value
523       * is computed just once for each instance and reused
524       * throughout its life.
525       * </p>
526       *
527       * @return a @link{java.lang.String} instance representing
528       *         the instance in textual form.
529       */
530      public String toString()
531      {
532        if (string == null)
533          string = getClass().getName()
534            + "[name=" + getName()
535            + ",openType=" + openType
536            + ",isReadable=" + isReadable()
537            + ",isWritable=" + isWritable()
538            + ",isIs=" + isIs()
539            + ",defaultValue=" + defaultValue
540            + ",minValue=" + minValue
541            + ",maxValue=" + maxValue
542            + ",legalValues=" + legalValues
543            + "]";
544        return string;
545      }
546    
547    }