001/* OpenMBeanOperationInfo.java -- Open typed info about a operation.
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 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 */
052public 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}