commons-jcs-core/src/main/java/org/apache/commons/jcs3/engine/control/group/GroupId.java

package org.apache.commons.jcs3.engine.control.group;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.Serializable;

/**
 * Used to avoid name conflict when group cache items are mixed with non-group cache items in the
 * same cache.
 */
public class GroupId
    implements Serializable
{
    /** Don't change. */
    private static final long serialVersionUID = 4626368486444860133L;

    /** Description of the Field */
    public final String groupName;

    /** the name of the region. */
    public final String cacheName;

    /** Cached toString value. */
    private String toString;

    /**
     * Constructor for the GroupId object
     * <p>
     * @param cacheName
     * @param groupName
     */
    public GroupId( final String cacheName, final String groupName )
    {
        this.cacheName = cacheName;
        this.groupName = groupName;

        if ( cacheName == null )
        {
            throw new IllegalArgumentException( "cacheName must not be null." );
        }
        if ( groupName == null )
        {
            throw new IllegalArgumentException( "groupName must not be null." );
        }
    }

    /**
     * @param obj
     * @return cacheName.equals( g.cacheName ) &amp;&amp;groupName.equals( g.groupName );
     */
    @Override
    public boolean equals( final Object obj )
    {
        if ( obj == null || !( obj instanceof GroupId ) )
        {
            return false;
        }
        final GroupId g = (GroupId) obj;
        return cacheName.equals( g.cacheName ) && groupName.equals( g.groupName );
    }

    /**
     * @return cacheName.hashCode() + groupName.hashCode();
     */
    @Override
    public int hashCode()
    {
        return cacheName.hashCode() + groupName.hashCode();
    }

    /**
     * Caches the value.
     * <p>
     * @return debugging string.
     */
    @Override
    public String toString()
    {
        if ( toString == null )
        {
            toString = "[groupId=" + cacheName + ", " + groupName + ']';
        }

        return toString;
    }
}