001/* OpenMBeanOperationInfoSupport.java -- Open typed info about an operation.
002   Copyright (C) 2006, 2007 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.management.openmbean;
039
040import java.util.Arrays;
041
042import javax.management.MBeanOperationInfo;
043import 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 */
051public 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}