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 */ 017package org.apache.commons.rng.core.source32; 018 019import java.util.Random; 020import java.io.IOException; 021import java.io.ObjectOutputStream; 022import java.io.ObjectInputStream; 023import java.io.ByteArrayOutputStream; 024import java.io.ByteArrayInputStream; 025 026/** 027 * A provider that uses the {@link Random#nextInt()} method of the JDK's 028 * {@link Random} class as the source of randomness. 029 * 030 * <p> 031 * <b>Caveat:</b> All the other calls will be redirected to the methods 032 * implemented within this library. 033 * </p> 034 * 035 * <p> 036 * The state of this source of randomness is saved and restored through 037 * the serialization of the {@link Random} instance. 038 * </p> 039 * 040 * @since 1.0 041 */ 042public class JDKRandom extends IntProvider { 043 /** Delegate. Cannot be "final" (to allow serialization). */ 044 private Random delegate; 045 046 /** 047 * Creates an instance with the given seed. 048 * 049 * @param seed Initial seed. 050 */ 051 public JDKRandom(Long seed) { 052 delegate = new Random(seed); 053 } 054 055 /** 056 * {@inheritDoc} 057 * 058 * @see Random#nextInt() 059 */ 060 @Override 061 public int next() { 062 return delegate.nextInt(); 063 } 064 065 /** {@inheritDoc} */ 066 @Override 067 protected byte[] getStateInternal() { 068 try { 069 final ByteArrayOutputStream bos = new ByteArrayOutputStream(); 070 final ObjectOutputStream oos = new ObjectOutputStream(bos); 071 072 // Serialize the "delegate". 073 oos.writeObject(delegate); 074 075 return bos.toByteArray(); 076 } catch (IOException e) { 077 // Workaround checked exception. 078 throw new RuntimeException(e); 079 } 080 } 081 082 /** {@inheritDoc} */ 083 @Override 084 protected void setStateInternal(byte[] s) { 085 try { 086 final ByteArrayInputStream bis = new ByteArrayInputStream(s); 087 final ObjectInputStream ois = new ObjectInputStream(bis); 088 089 delegate = (Random) ois.readObject(); 090 } catch (ClassNotFoundException e) { 091 // Workaround checked exception. 092 throw new RuntimeException(e); 093 } catch (IOException e) { 094 // Workaround checked exception. 095 throw new RuntimeException(e); 096 } 097 } 098}