001    /* OpenMBeanOperationInfoSupport.java -- Open typed info about an operation.
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.Arrays;
041    
042    import javax.management.MBeanOperationInfo;
043    import javax.management.MBeanParameterInfo;
044    
045    /**
046     * Describes a operation for an open management bean.
047     *
048     * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
049     * @since 1.5
050     */
051    public class OpenMBeanOperationInfoSupport
052      extends MBeanOperationInfo
053      implements OpenMBeanOperationInfo
054    {
055    
056      /**
057       * Compatible with JDK 1.5
058       */
059      private static final long serialVersionUID = 4996859732565369366L;
060    
061      /**
062       * The open type representing the return value.
063       */
064      private OpenType<?> returnOpenType;
065    
066      /**
067       * The hash code of this instance.
068       */
069      private transient Integer hashCode;
070    
071      /**
072       * The <code>toString()</code> result of this instance.
073       */
074      private transient String string;
075    
076      /**
077       * Constructs a @link{OpenMBeanOperationInfo} with the specified name,
078       * description, parameter information, open return type and impact. A
079       * <code>null</code> value for the parameter information is the same
080       * as passing in an empty array.  A copy of the parameter array is
081       * taken, so later changes have no effect.  The name and the
082       * description may not be equal to the empty string, and neither
083       * the name, description nor the open return type may be
084       * <code>null</code>.  The value of <code>impact</code> must be
085       * one of the four valid values
086       * ({@link javax.management.MBeanOperationInfo#INFO},
087       * {@link javax.management.MBeanOperationInfo#ACTION},
088       * {@link javax.management.MBeanOperationInfo#ACTION_INFO} and
089       * {@link javax.management.MBeanOperationInfo#UNKNOWN}).
090       *
091       *
092       * @param name the name of the constructor.
093       * @param desc a description of the attribute.
094       * @param sig the signature of the method, as a series
095       *            of {@link MBeanParameterInfo} objects, one for
096       *            each parameter.
097       * @param type the open return type of the method.
098       * @param impact the impact of performing the operation.
099       * @throws IllegalArgumentException if the name, description or
100       *                                  open return type is <code>null</code>,
101       *                                  the name or description are equal to
102       *                                  the empty string, or the impact factor
103       *                                  is not one of the values enumerated
104       *                                  above.
105       * @throws ArrayStoreException if the members of the signature array
106       *                             are not assignable to
107       *                             {@link javax.management.MBeanParameterInfo}
108       */
109      public OpenMBeanOperationInfoSupport(String name, String desc,
110                                           OpenMBeanParameterInfo[] sig,
111                                           OpenType<?> type, int impact)
112      {
113        super(name, desc, (MBeanParameterInfo[]) sig,
114              type == null ? null : type.getClassName(), impact);
115        if (name == null)
116          throw new IllegalArgumentException("The name may not be null.");
117        if (desc == null)
118          throw new IllegalArgumentException("The description may not be null.");
119        if (type == null)
120          throw new IllegalArgumentException("The type may not be null.");
121        if (name.length() == 0)
122          throw new IllegalArgumentException("The name may not be the empty string.");
123        if (desc.length() == 0)
124          throw new IllegalArgumentException("The description may not be the " +
125                                             "empty string.");
126        if (impact != ACTION && impact != INFO &&
127            impact != ACTION_INFO && impact != UNKNOWN)
128          throw new IllegalArgumentException("The impact factor is an invalid value.");
129        returnOpenType = type;
130      }
131    
132      /**
133       * Compares this attribute with the supplied object.  This returns
134       * true iff the object is an instance of {@link OpenMBeanOperationInfo}
135       * with an equal name, signature, open return type and impact.
136       *
137       * @param obj the object to compare.
138       * @return true if the object is a {@link OpenMBeanParameterInfo}
139       *         instance,
140       *         <code>name.equals(object.getName())</code>,
141       *         <code>signature.equals(object.getSignature())</code>,
142       *         <code>returnOpenType.equals(object.getReturnOpenType())</code>,
143       *         and <code>impact == object.getImpact()</code>.
144       */
145      public boolean equals(Object obj)
146      {
147        if (!(obj instanceof OpenMBeanOperationInfo))
148          return false;
149        OpenMBeanOperationInfo o = (OpenMBeanOperationInfo) obj;
150        return getName().equals(o.getName()) &&
151          getSignature().equals(o.getSignature()) &&
152          returnOpenType.equals(o.getReturnOpenType()) &&
153          getImpact() == o.getImpact();
154      }
155    
156      /**
157       * Returns the open type instance which represents the type of the
158       * return value.
159       *
160       * @return the open type of the return value.
161       */
162      public OpenType<?> getReturnOpenType()
163      {
164        return returnOpenType;
165      }
166    
167      /**
168       * <p>
169       * Returns the hashcode of the operation information as the sum of
170       * the hashcodes of the name, open return type, impact and signature
171       * (calculated by
172       * <code>java.util.Arrays.asList(signature).hashCode()</code>).
173       * </p>
174       * <p>
175       * As instances of this class are immutable, the return value
176       * is computed just once for each instance and reused
177       * throughout its life.
178       * </p>
179       *
180       * @return the hashcode of the operation information.
181       */
182      public int hashCode()
183      {
184        if (hashCode == null)
185          hashCode = Integer.valueOf(getName().hashCode() +
186                                     returnOpenType.hashCode() +
187                                     Integer.valueOf(getImpact()).hashCode() +
188                                     Arrays.asList(getSignature()).hashCode());
189        return hashCode.intValue();
190      }
191    
192      /**
193       * <p>
194       * Returns a textual representation of this instance.  This
195       * is constructed using the class name
196       * (<code>javax.management.openmbean.OpenMBeanOperationInfo</code>)
197       * along with the name, signature, open return type and impact.
198       * </p>
199       * <p>
200       * As instances of this class are immutable, the return value
201       * is computed just once for each instance and reused
202       * throughout its life.
203       * </p>
204       *
205       * @return a @link{java.lang.String} instance representing
206       *         the instance in textual form.
207       */
208      public String toString()
209      {
210        if (string == null)
211          {
212            String impactString;
213            switch (getImpact())
214              {
215              case INFO:
216                impactString = "INFO";
217                break;
218              case ACTION:
219                impactString = "ACTION";
220                break;
221              case ACTION_INFO:
222                impactString = "ACTION_INFO";
223                break;
224              case UNKNOWN:
225                impactString = "UNKNOWN";
226                break;
227              default:
228                impactString = "ERRONEOUS VALUE";
229              }
230            string = getClass().getName()
231              + "[name=" + getName()
232              + ",signature=" + Arrays.toString(getSignature())
233              + ",returnOpenType=" + returnOpenType
234              + ",impact=" + impactString
235              + "]";
236          }
237        return string;
238      }
239    
240    }