001/* OpenMBeanConstructorInfoSupport.java -- Open typed info about an constructor.
002   Copyright (C) 2006 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.MBeanConstructorInfo;
043import javax.management.MBeanParameterInfo;
044
045/**
046 * Describes a constructor for an open management bean.
047 *
048 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
049 * @since 1.5
050 */
051public class OpenMBeanConstructorInfoSupport
052  extends MBeanConstructorInfo
053  implements OpenMBeanConstructorInfo
054{
055
056  /**
057   * Compatible with JDK 1.5
058   */
059  private static final long serialVersionUID = -4400441579007477003L;
060
061  /**
062   * The hash code of this instance.
063   */
064  private transient Integer hashCode;
065
066  /**
067   * The <code>toString()</code> result of this instance.
068   */
069  private transient String string;
070
071  /**
072   * Constructs a @link{OpenMBeanConstructorInfo} with the specified
073   * name, description and parameter information. A <code>null</code>
074   * value for the parameter information is the same as passing in
075   * an empty array.  Neither the name nor the description may be
076   * null or equal to the empty string.  A copy of the parameter array
077   * is taken, so later changes have no effect.
078   *
079   * @param name the name of the constructor.
080   * @param desc a description of the constructor.
081   * @param sig the signature of the constructor, as a series
082   *            of {@link MBeanParameterInfo} objects, one for
083   *            each parameter.
084   * @throws IllegalArgumentException if the name or description is
085   *                                  either <code>null</code>
086   *                                  or the empty string.
087   * @throws ArrayStoreException if the members of the signature array
088   *                             are not assignable to
089   *                             {@link javax.management.MBeanParameterInfo}
090   */
091  public OpenMBeanConstructorInfoSupport(String name, String desc,
092                                         OpenMBeanParameterInfo[] sig)
093  {
094    super(name, desc, (MBeanParameterInfo[]) sig);
095    if (name == null)
096      throw new IllegalArgumentException("The name may not be null.");
097    if (desc == null)
098      throw new IllegalArgumentException("The description may not be null.");
099    if (name.length() == 0)
100      throw new IllegalArgumentException("The name may not be the empty string.");
101    if (desc.length() == 0)
102      throw new IllegalArgumentException("The description may not be the " +
103                                         "empty string.");
104  }
105
106  /**
107   * Compares this attribute with the supplied object.  This returns
108   * true iff the object is an instance of {@link OpenMBeanConstructorInfo}
109   * with an equal name and signature.
110   *
111   * @param obj the object to compare.
112   * @return true if the object is a {@link OpenMBeanParameterInfo}
113   *         instance,
114   *         <code>name.equals(object.getName())</code>,
115   *         and <code>signature.equals(object.getSignature())</code>.
116   */
117  public boolean equals(Object obj)
118  {
119    if (!(obj instanceof OpenMBeanConstructorInfo))
120      return false;
121    OpenMBeanConstructorInfo o = (OpenMBeanConstructorInfo) obj;
122    return getName().equals(o.getName()) &&
123      getSignature().equals(o.getSignature());
124  }
125
126  /**
127   * <p>
128   * Returns the hashcode of the constructor information as the sum of
129   * the hashcodes of the name and signature (calculated by
130   * <code>java.util.Arrays.asList(signature).hashCode()</code>).
131   * </p>
132   * <p>
133   * As instances of this class are immutable, the return value
134   * is computed just once for each instance and reused
135   * throughout its life.
136   * </p>
137   *
138   * @return the hashcode of the constructor information.
139   */
140  public int hashCode()
141  {
142    if (hashCode == null)
143      hashCode = Integer.valueOf(getName().hashCode() +
144                                 Arrays.asList(getSignature()).hashCode());
145    return hashCode.intValue();
146  }
147
148  /**
149   * <p>
150   * Returns a textual representation of this instance.  This
151   * is constructed using the class name
152   * (<code>javax.management.openmbean.OpenMBeanConstructorInfo</code>)
153   * along with the name and signature.
154   * </p>
155   * <p>
156   * As instances of this class are immutable, the return value
157   * is computed just once for each instance and reused
158   * throughout its life.
159   * </p>
160   *
161   * @return a @link{java.lang.String} instance representing
162   *         the instance in textual form.
163   */
164  public String toString()
165  {
166    if (string == null)
167      string = getClass().getName()
168        + "[name=" + getName()
169        + ",signature=" + Arrays.toString(getSignature())
170        + "]";
171    return string;
172  }
173
174}