1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.id; 18 19 /** 20 * Abstract superclass for StringIdentifierGenerator implementations. 21 * 22 * @author Commons-Id team 23 * @version $Id: AbstractStringIdentifierGenerator.java 480488 2006-11-29 08:57:26Z bayard $ 24 */ 25 public abstract class AbstractStringIdentifierGenerator implements StringIdentifierGenerator { 26 27 /** 28 * Maximum length for a numeric string representing a long value. 29 */ 30 protected static final int MAX_LONG_NUMERIC_VALUE_LENGTH = 31 Long.toString(Long.MIN_VALUE).length(); 32 33 /** 34 * Number of alphanumeric characters. 35 */ 36 protected static final int ALPHA_NUMERIC_CHARSET_SIZE = 36; 37 38 /** 39 * Maximum length for an alphanumeric string representing a long value. 40 */ 41 protected static final int MAX_LONG_ALPHANUMERIC_VALUE_LENGTH = 42 Long.toString(Long.MAX_VALUE, ALPHA_NUMERIC_CHARSET_SIZE).length(); 43 44 /** 45 * Maximum length for a numeric string representing an integer value. 46 */ 47 protected static final int MAX_INT_NUMERIC_VALUE_LENGTH = 48 Integer.toString(Integer.MIN_VALUE).length(); 49 50 /** 51 * Maximum length for an alphanumeric string representing an integer value. 52 */ 53 protected static final int MAX_INT_ALPHANUMERIC_VALUE_LENGTH = 54 Integer.toString(Integer.MAX_VALUE, ALPHA_NUMERIC_CHARSET_SIZE).length(); 55 56 /** 57 * Default size of an alphanumeric identifier. 58 */ 59 protected static final int DEFAULT_ALPHANUMERIC_IDENTIFIER_SIZE = 15; 60 61 /** 62 * Constructor. 63 */ 64 protected AbstractStringIdentifierGenerator() { 65 super(); 66 } 67 68 public abstract String nextStringIdentifier(); 69 70 /** 71 * Returns the maximum length (number or characters) for an identifier 72 * from this sequence. 73 * 74 * <p>The default implementation returns {@link #INFINITE_MAX_LENGTH}. Implementations 75 * with bounded length identifiers should override this method to 76 * return the maximum length of a generated identifier.</p> 77 * 78 * @return {@inheritDoc} 79 */ 80 public long maxLength() { 81 return INFINITE_MAX_LENGTH; 82 } 83 84 /** 85 * Returns the minimum length (number of characters) for an identifier 86 * from this sequence. 87 * 88 * <p>The default implementation returns 0. Implementations 89 * with identifiers having a postive minimum length should override this 90 * method to return the maximum length of a generated identifier.</p> 91 * 92 * @return {@inheritDoc} 93 */ 94 public long minLength() { 95 return 0; 96 } 97 98 public Object nextIdentifier() { 99 return nextStringIdentifier(); 100 } 101 }