com.unboundid.util.ThreadLocalSecureRandom Maven / Gradle / Ivy
/*
* Copyright 2021-2022 Ping Identity Corporation
* All Rights Reserved.
*/
/*
* Copyright 2021-2022 Ping Identity Corporation
*
* 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.
*/
/*
* Copyright (C) 2021-2022 Ping Identity Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (GPLv2 only)
* or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see .
*/
package com.unboundid.util;
import java.security.SecureRandom;
/**
* This class provides a means of obtaining a thread-local {@code SecureRandom}
* instance that can be used without synchronization or contention.
*/
@ThreadSafety(level=ThreadSafetyLevel.COMPLETELY_THREADSAFE)
public final class ThreadLocalSecureRandom
{
/**
* The thread-local instances that have been created.
*/
@NotNull private static final ThreadLocal INSTANCES =
new ThreadLocal<>();
/**
* Prevents this utility class from being instantiated.
*/
private ThreadLocalSecureRandom()
{
// No implementation is required.
}
/**
* Retrieves a thread-local {@code SecureRandom} instance.
*
* @return A thread-local {@code SecureRandom} instance.
*/
@NotNull()
public static SecureRandom get()
{
SecureRandom random = INSTANCES.get();
if (random == null)
{
random = CryptoHelper.getSecureRandom();
INSTANCES.set(random);
}
return random;
}
}