| /* |
| * Copyright 2008 Niclas Hedhman. All rights Reserved. |
| * |
| * Licensed 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.qi4j.library.uid.uuid; |
| |
| import java.util.UUID; |
| |
| public class UuidGenerationMixin |
| implements UuidService |
| { |
| private String uuid; |
| private int count; |
| |
| public UuidGenerationMixin() |
| { |
| uuid = UUID.randomUUID().toString() + "-"; |
| } |
| |
| @Override |
| public String generateUuid( int hashLength ) |
| { |
| synchronized( this ) |
| { |
| String uid = this.uuid + Integer.toHexString( count++ ); |
| if( hashLength > 0 ) |
| { |
| byte[] result = new byte[hashLength]; |
| byte[] bytes = uid.getBytes(); |
| for( int i = 0; i < bytes.length; i++ ) |
| { |
| int pos = i % hashLength; |
| result[ pos ] = (byte) ( result[ pos ] * 31 + 19 + bytes[ i ] ); |
| } |
| StringBuffer buf = new StringBuffer(); |
| for( int data : result ) |
| { |
| if( data < 0 ) |
| { |
| data = 256 + data; |
| } |
| String hex = Integer.toHexString( data ); |
| if( hex.length() == 1 ) |
| { |
| hex = "0" + hex; |
| } |
| buf = buf.append( hex ); |
| } |
| uid = buf.toString(); |
| } |
| return uid.toUpperCase(); |
| } |
| } |
| } |