Here you can find the source of random()
private static Random random()
//package com.java2s; /*/* w ww. j a v a2s .co m*/ * Copyright 2011 <a href="mailto:jinahya@gmail.com">Jin Kwon</a>. * * 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. */ import java.util.Random; import java.util.concurrent.ThreadLocalRandom; public class Main { private static Random random() { return ThreadLocalRandom.current(); } }