先上Demo public static void main(String[] args) throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException { // TODO Auto-generated method stub Test test = new Test(4,5); Field field1 = test.getClass().getDeclaredField("x"); field1.setAccessible(true); System.out.println(field1.get(test)); } Test类 */ public class Test { private int x; public int y; public Test(int x, int y) { super(); this.x = x; this.y = y; } } 先获得Test类的字节码getClass(),然后再获得类的声明变量x,将其属性的访问性设为TRUE,变暴力反射出私有成员。