001    /* OpenMBeanOperationInfo.java -- Open typed info about a operation.
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.openmbean;
039    
040    import javax.management.MBeanParameterInfo;
041    
042    /**
043     * Describes a operation for an open management bean.
044     * This interface includes those methods specified by {@link
045     * javax.management.MBeanOperationInfo}, so implementations should
046     * extend this class.  The {@link #getSignature()} method should
047     * return an array containing instances of {@link OpenMBeanParameterInfo}.
048     *
049     * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
050     * @since 1.5
051     */
052    public interface OpenMBeanOperationInfo
053    {
054    
055      /**
056       * Compares this attribute with the supplied object.  This returns
057       * true iff the object is an instance of {@link OpenMBeanOperationInfo}
058       * with an equal name, signature, open return type and impact.
059       *
060       * @param obj the object to compare.
061       * @return true if the object is a {@link OpenMBeanParameterInfo}
062       *         instance, 
063       *         <code>name.equals(object.getName())</code>,
064       *         <code>signature.equals(object.getSignature())</code>,
065       *         <code>returnOpenType.equals(object.getReturnOpenType())</code>,
066       *         and <code>impact == object.getImpact()</code>.
067       */
068      boolean equals(Object obj);
069    
070      /**
071       * Returns a description of this operation.
072       *
073       * @return a human-readable description.
074       */
075      String getDescription();
076    
077      /**
078       * <p>
079       * Returns the impact of performing this operation.
080       * The value is equal to one of the following:
081       * </p>
082       * <ol>
083       * <li>{@link javax.management.MBeanOperationInfo#INFO}
084       * &mdash; the method just returns
085       * information (akin to an accessor).</li>
086       * <li>{@link javax.management.MBeanOperationInfo#ACTION}
087       * the method just alters the state of the bean, without
088       * returning a value (akin to a mutator).</li>
089       * <li>{@link javax.management.MBeanOperationInfo#ACTION_INFO}
090       * the method both makes state changes and returns a value.</li>
091       * <li>{@link javax.management.MBeanOperationInfo#UNKNOWN}
092       * the behaviour of the operation is unknown.</li>
093       * </ol>
094       *
095       * @return the impact of performing the operation.
096       */
097      int getImpact();
098    
099      /**
100       * Returns the name of this operation.
101       *
102       * @return the name of the operation.
103       */
104      String getName();
105    
106      /**
107       * Returns the open type instance which represents the type of the
108       * return value.
109       *
110       * @return the open type of the return value.
111       */
112      OpenType<?> getReturnOpenType();
113    
114      /**
115       * Returns the return type of the operation, as the class
116       * name.  This should be identical to
117       * <code>getReturnOpenType.getClassName()</code>.
118       *
119       * @return the return type.
120       */
121      String getReturnType();
122    
123      /**
124       * Returns the operation's signature, in the form of
125       * information on each parameter.  Each parameter is
126       * described by an instance of {@link OpenMBeanParameterInfo}.
127       *
128       * @return an array of {@link OpenMBeanParameterInfo} objects,
129       *         describing the operation parameters.
130       */
131      MBeanParameterInfo[] getSignature();
132    
133      /**
134       * Returns the hashcode of the operation information as the sum of
135       * the hashcodes of the name, open return type, impact and signature
136       * (calculated by
137       * <code>java.util.Arrays.asList(signature).hashCode()</code>).
138       *
139       * @return the hashcode of the operation information.
140       */
141      int hashCode();
142    
143      /**
144       * Returns a textual representation of this instance.  This
145       * is constructed using the class name
146       * (<code>javax.management.openmbean.OpenMBeanOperationInfo</code>)
147       * along with the name, signature, open return type and impact.
148       *
149       * @return a @link{java.lang.String} instance representing
150       *         the instance in textual form.
151       */
152      String toString();
153    
154    }