java写程序2+2=5,你相信吗?

来看段代码

public class Test {
	public static void main(String[] args) throws Exception, NoSuchFieldException {
		Class cache = Integer.class.getDeclaredClasses()[0];
	    Field c = cache.getDeclaredField("cache");
	    c.setAccessible(true);
	    Integer[] array = (Integer[]) c.get(cache);
	    array[132] = array[133];
	
	    System.out.printf("%d",2 + 2);
	}
}

运行结果

5