core/src/main/java/org/apache/directory/server/core/configuration/ConfigurationUtil.java

/*
 *  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. 
 *  
 */
package org.apache.directory.server.core.configuration;


import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.apache.directory.shared.ldap.ldif.Entry;


/**
 * A utility class that provides common functionality while validating configuration.
 * 
 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
 * @version $Rev$, $Date$
 */
public class ConfigurationUtil
{
    /**
     * Checks all elements of the specified set is of the specified type,
     * and returns cloned set.
     * 
     * @throws ConfigurationException if the specified set has an element of wrong type
     */
    public static Set getTypeSafeSet( Set set, Class type )
    {
        Set newSet = new HashSet();
        getTypeSafeCollection( set, type, newSet );
        return newSet;
    }


    /**
     * Checks all elements of the specified list is of the specified type,
     * and returns cloned list.
     * 
     * @throws ConfigurationException if the specified set has an element of wrong type
     */
    public static List getTypeSafeList( List list, Class type )
    {
        List newList = new ArrayList();
        getTypeSafeCollection( list, type, newList );
        return newList;
    }


    public static void getTypeSafeCollection( Collection collection, Class type, Collection newCollection )
    {
        Iterator i = collection.iterator();
        while ( i.hasNext() )
        {
            Object e = i.next();
            if ( !type.isAssignableFrom( e.getClass() ) )
            {
                throw new ConfigurationException( "Invalid element type: " + e.getClass() + " (expected " + type );
            }
            newCollection.add( e );
        }
    }


    /**
     * Returns the clone of the specified set.
     */
    public static Set getClonedSet( Set set )
    {
        Set newSet = new HashSet();
        newSet.addAll( set );
        return newSet;
    }


    /**
     * Returns the clone of the specified list.
     */
    public static List getClonedList( List list )
    {
        List newList = new ArrayList();
        newList.addAll( list );
        return newList;
    }


    /**
     * Returns the deep clone of the specified {@link Attributes} list.
     */
    public static List getClonedAttributesList( List list ) throws CloneNotSupportedException
    {
        List newList = new ArrayList();
        Iterator i = list.iterator();
        
        while ( i.hasNext() )
        {
            newList.add( ( ( Entry ) i.next() ).clone() );
        }
        return newList;
    }


    /**
     * Throws a {@link ConfigurationException} if the specified port number
     * is out of range.
     */
    public static void validatePortNumber( int port )
    {
        if ( port < 0 || port > 65535 )
        {
            throw new ConfigurationException( "Invalid port number: " + port );
        }
    }


    private ConfigurationUtil()
    {
    }
}