如何从java类外部调用私有方法
问题描述:
我有一个 Dummy
类,它有一个名为 sayHello
的私有方法。我想从 Dummy
外面打电话给 sayHello
。我认为它应该可以反射,但我得到一个 IllegalAccessException
。任何想法???
I have a Dummy
class that has a private method called sayHello
. I want to call sayHello
from outside Dummy
. I think it should be possible with reflection but I get an IllegalAccessException
. Any ideas???
答
使用 setAccessible(true)
使用调用
方法之前的方法对象。
use setAccessible(true)
on your Method object before using its invoke
method.
import java.lang.reflect.*;
class Dummy{
private void foo(){
System.out.println("hello foo()");
}
}
class Test{
public static void main(String[] args) throws Exception {
Dummy d = new Dummy();
Method m = Dummy.class.getDeclaredMethod("foo");
//m.invoke(d);// throws java.lang.IllegalAccessException
m.setAccessible(true);// Abracadabra
m.invoke(d);// now its OK
}
}