Java/reflection - where's error?

Question

I found some posts about java/reflection on this site. But still can't understand something. Could anyone tell where's error in my code? (need to print "HELLO!")

Output:

java.lang.NoSuchMethodException: Caller.foo()

Here's my Main.java:

import java.lang.reflect.*;

class Main {

    public static void main(String[] args) {
        Caller cal = new Caller();
        Method met;
        try {
            met = cal.getClass().getMethod("foo", new Class[]{});
            met.invoke(cal);
        } catch (Exception e) {
            System.out.println(e.toString());
        }
    }
}

class Caller {
    void foo() {
        System.out.println("HELLO!");
    }
}

Keppil · Accepted Answer · 2012-10-25 12:07:06Z

10

getMethod() only finds public methods. Either change the access modifier of the Caller#foo() method to public, or use getDeclaredMethod() instead.

answered Oct 25, 2012 at 12:07

Keppil

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2 Comments

andyb Over a year ago

Yes, the scope for foo() is package-private (no explicit modifier)

Alf Over a year ago

Yeah! getDeclaredMethod() - cause I need to keep both classes in the same file.

tux23 · Accepted Answer · 2012-10-25 12:17:09Z

0

import java.lang.reflect.*;

public static void main(String[] args) {
    public static void main(String[] args) {
        try {
            Class c = Class.forName("Caller"); 
            Object obj = c.newInstance();
            Method m = c.getMethod("foo");
            m.invoke(obj);
        } catch (Exception e) {
            System.out.println(e.toString());
        }           
    }
}

public class Caller {
    public void foo() {
        System.out.println("HELLO!");
    }
}

answered Oct 25, 2012 at 12:17

tux23

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