java基础类库学习（一.4）Random与ThreadLocalRandom类

这些类是用来生成伪随机数的，，但是ThreadLocalRandom类相比Random类在多线程环境下可以较少多线程资源竞争，保证线程安全

Random源码？

public class Random implements java.io.Serializable {

static final long serialVersionUID = 3905348978240129619L;

private final AtomicLong seed;

public Random() {
    this(seedUniquifier() ^ System.nanoTime());
}

public Random(long seed) {
    if (getClass() == Random.class)
        this.seed = new AtomicLong(initialScramble(seed));
    else {
        // subclass might have overriden setSeed
        this.seed = new AtomicLong();
        setSeed(seed);
    }
}

synchronized public void setSeed(long seed) {
    this.seed.set(initialScramble(seed));
    haveNextNextGaussian = false;
}

}

ThreadLocalRandom源码类？

public class ThreadLocalRandom extends Random {
    

private static final AtomicInteger probeGenerator =
    new AtomicInteger();

private static final AtomicLong seeder = new AtomicLong(initialSeed());

private ThreadLocalRandom() {
    initialized = true; // false during super() call
}

static final ThreadLocalRandom instance = new ThreadLocalRandom();

}