1 /* 2 * Copyright 2017, OpenCensus Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.opencensus.implcore.trace.internal; 18 19 import java.security.SecureRandom; 20 import java.util.Random; 21 import javax.annotation.concurrent.ThreadSafe; 22 23 /** 24 * Abstract class to access the current {@link Random}. 25 * 26 * <p>Implementation can have a per thread instance or a single global instance. 27 */ 28 @ThreadSafe 29 public abstract class RandomHandler { 30 /** 31 * Returns the current {@link Random}. 32 * 33 * @return the current {@code Random}. 34 */ 35 public abstract Random current(); 36 37 /** Implementation of the {@link RandomHandler} using {@link SecureRandom}. */ 38 @ThreadSafe 39 public static final class SecureRandomHandler extends RandomHandler { 40 private final Random random = new SecureRandom(); 41 42 /** Constructs a new {@link SecureRandomHandler}. */ 43 public SecureRandomHandler() {} 44 45 @Override 46 public Random current() { 47 return random; 48 } 49 } 50 } 51