java.util.concurrent package的API文档陈述如下：

[…] Additionally, classes are provided only for those types that are commonly useful in intended applications. For example, there is no atomic class for representing byte. In those infrequent cases where you would like to do so, you can use an AtomicInteger to hold byte values, and cast appropriately. You can also hold floats using Float.floatToIntBits and Float.intBitstoFloat conversions, and doubles using Double.doubleToLongBits and Double.longBitsToDouble conversions.

我不是说这是一个方便的解决方案，但这似乎是解释。我想你可能想要包装一个AtomicInteger，并提供访问方法getFloat / setFloat等。

我实际上写了一个。干得好：

import java.util.concurrent.atomic.AtomicInteger;

import static java.lang.Float.*;

class AtomicFloat extends Number {

private AtomicInteger bits;

public AtomicFloat() {

this(0f);

}

public AtomicFloat(float initialValue) {

bits = new AtomicInteger(floatToIntBits(initialValue));

}

public final boolean compareAndSet(float expect, float update) {

return bits.compareAndSet(floatToIntBits(expect),

floatToIntBits(update));

}

public final void set(float newValue) {

bits.set(floatToIntBits(newValue));

}

public final float get() {

return intBitsToFloat(bits.get());

}

public float floatValue() {

return get();

}

public final float getAndSet(float newValue) {

return intBitsToFloat(bits.getAndSet(floatToIntBits(newValue)));

}

public final boolean weakCompareAndSet(float expect, float update) {

return bits.weakCompareAndSet(floatToIntBits(expect),

floatToIntBits(update));

}

public double doubleValue() { return (double) floatValue(); }

public int intValue() { return (int) get(); }

public long longValue() { return (long) get(); }

}