使用jmh更新
使用jmh，我得到类似的结果，除了
clone似乎稍微好一点。
原始帖子
我对性能进行了一个快速测试：
clone，
System.arrayCopy并且
Arrays.copyOf具有非常相似的性能（jdk
1.7.06，服务器虚拟机）。
有关详细信息（以毫秒为单位），请在JIT之后：
克隆：68个
数组复制：68个
Arrays.copyOf：68
测试代码：
public static void main(String[] args) throws InterruptedException, IOException { int sum = 0; int[] warmup = new int[1]; warmup[0] = 1; for (int i = 0; i < 15000; i++) { // triggers JIT sum += copyClone(warmup); sum += copyArrayCopy(warmup); sum += copyCopyOf(warmup); } int count = 10_000_000; int[] array = new int[count]; for (int i = 0; i < count; i++) { array[i] = i; } // additional warmup for main for (int i = 0; i < 10; i++) { sum += copyArrayCopy(array); } System.gc(); // copyClone long start = System.nanoTime(); for (int i = 0; i < 10; i++) { sum += copyClone(array); } long end = System.nanoTime(); System.out.println("clone: " + (end - start) / 1000000); System.gc(); // copyArrayCopy start = System.nanoTime(); for (int i = 0; i < 10; i++) { sum += copyArrayCopy(array); } end = System.nanoTime(); System.out.println("arrayCopy: " + (end - start) / 1000000); System.gc(); // copyCopyOf start = System.nanoTime(); for (int i = 0; i < 10; i++) { sum += copyCopyOf(array); } end = System.nanoTime(); System.out.println("Arrays.copyOf: " + (end - start) / 1000000); // sum System.out.println(sum);}private static int copyClone(int[] array) { int[] copy = array.clone(); return copy[copy.length - 1];}private static int copyArrayCopy(int[] array) { int[] copy = new int[array.length]; System.arraycopy(array, 0, copy, 0, array.length); return copy[copy.length - 1];}private static int copyCopyOf(int[] array) { int[] copy = Arrays.copyOf(array, array.length); return copy[copy.length - 1];}
