/*
 * 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.lenya.transaction;

import org.apache.commons.lang.Validate;

/**
 * Exception which is thrown when a different identity changed a transactionable
 * object in an optimistic offline lock scenario.
 */
public class ConcurrentModificationException extends TransactionException {

    private Transactionable transactionable;

    public ConcurrentModificationException(Transactionable t) {
        super();
        Validate.notNull(t);
        this.transactionable = t;
    }

    public String getMessage() {
        return "The object [" + this.transactionable + "] was modified after it has been locked.";
    }

    /**
     * @return The transactionable that was modified by a different identity.
     */
    public Transactionable getTransactionable() {
        return this.transactionable;
    }

}