001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     * 
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     * 
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */ 
017    package org.apache.commons.betwixt.io;
018    
019    
020    /** <p>Interface allowing pluggable <code>ID</code> attribute value generators.</p>
021      *
022      * <p> <code>IDGenerator</code>'s are used to generate <code>ID</code>
023      * attribute values by <code>BeanWriter</code>. 
024      * A user can specify the generation mechanism by passing an implementation to 
025      * {@link BeanWriter#setIdGenerator}.</p>
026      *
027      * <p>Standard implementations are included with that supply random and sequantial values.</p>
028      *
029      * @author <a href="mailto:rdonkin@apache.org">Robert Burrell Donkin</a>
030      * @version $Revision: 438373 $
031      */
032    public interface IDGenerator {
033        
034        /** 
035          * Get the last <code>ID</code> value generated.
036          *
037          * @return the last value generated
038          */
039        public String getLastId();
040        
041        /** 
042          * Generate a new  <code>ID</code> attribute value.
043          *
044          * @return next value
045          */
046        public String nextId();
047    }