001    /* MBeanParameterInfo.java -- Information about an operation's parameters.
002       Copyright (C) 2006 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;
039    
040    /**
041     * Describes the parameters of a constructor or operation associated
042     * with a management bean.  The information in this class is immutable
043     * as standard.  Of course, subclasses may change this, but this
044     * behaviour is not recommended.
045     *
046     * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
047     * @since 1.5
048     */
049    public class MBeanParameterInfo
050      extends MBeanFeatureInfo
051      implements Cloneable
052    {
053    
054      /**
055       * Compatible with JDK 1.5
056       */
057      private static final long serialVersionUID = 7432616882776782338L;
058    
059      /**
060       * The type of the parameter, represented by the class name.
061       */
062      private String type;
063    
064      /**
065       * Constructs a new {@link MBeanParameterInfo} using the specified
066       * name, description and type.  
067       *
068       * @param name the name of the attribute.
069       * @param type the type of the attribute, in the form of its class name.
070       * @param desc a description of the attribute.
071       */
072      public MBeanParameterInfo(String name, String type, String desc)
073      {
074        super(name, desc);
075        this.type = type;
076      }
077    
078      /**
079       * Returns a clone of this instance.  The clone is created
080       * using just the method provided by {@link java.lang.Object}.
081       * Thus, the clone is just a shallow clone as returned by
082       * that method, and does not contain any deeper cloning based
083       * on the subject of this class.
084       *
085       * @return a clone of this instance.
086       * @see java.lang.Cloneable
087       */
088      public Object clone()
089      {
090        try
091          {
092            return super.clone();
093          }
094        catch (CloneNotSupportedException e)
095          {
096            /* This shouldn't happen; we implement Cloneable */
097            throw new IllegalStateException("clone() called on " +
098                                            "non-cloneable object.");
099          }
100      }
101    
102      /**
103       * Compares this feature with the supplied object.  This returns
104       * true iff the object is an instance of {@link MBeanParameterInfo},
105       * {@link Object#equals()} returns true for a comparison of both the
106       * name and description of this parameter with that of the specified
107       * object (performed by the superclass), and the type of the two
108       * instances is equal.
109       *
110       * @param obj the object to compare.
111       * @return true if the object is a {@link MBeanParameterInfo}
112       *         instance, 
113       *         <code>name.equals(object.getName())</code>,
114       *         <code>description.equals(object.getDescription())</code>,
115       *         and <code>type.equals(object.getType())</code>.
116       */
117      public boolean equals(Object obj)
118      {
119        if (!(obj instanceof MBeanParameterInfo))
120          return false;
121        if (!(super.equals(obj)))
122          return false;
123        MBeanParameterInfo o = (MBeanParameterInfo) obj;
124        return type.equals(o.getType());
125      }
126    
127      /**
128       * Returns the type of this attribute, in the form of its class name.
129       *
130       * @return the type of this attribute.
131       */
132      public String getType()
133      {
134        return type;
135      }
136    
137      /**
138       * Returns the hashcode of the parameter information as the sum of
139       * the hashcode of the superclass and the hashcode of the type.
140       *
141       * @return the hashcode of the parameter information.
142       */
143      public int hashCode()
144      {
145        return super.hashCode() + type.hashCode();
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.MBeanParameterInfo</code>) along
153       * with the name, description and type of the parameter.
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          {
168            super.toString();
169            string = string.substring(0, string.length() - 1) 
170              + ",type=" + type
171              + "]";
172          }
173        return string;
174      }
175    
176    }