通过名称调用方法

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

class AnotherClass {
    private void m() {
    }
}

public class MethodTroubleAgain {
    public static void main(String... args) {
        AnotherClass ac = new AnotherClass();
        try {
            Class<?> c = ac.getClass();
            Method m = c.getDeclaredMethod("m");
            //        m.setAccessible(true);      // solution
            Object o = m.invoke(ac); // IllegalAccessException

            // production code should handle these exceptions more gracefully
        } catch (NoSuchMethodException x) {
            x.printStackTrace();
        } catch (InvocationTargetException x) {
            x.printStackTrace();
        } catch (IllegalAccessException x) {
            x.printStackTrace();
        }
    }
}