Question

I have following package structure and classes.

package  X 
    Class A
        private string fieldX;
        protected string getFieldX(){ return fieldX};

package Y
    Class B extends A
    Class C extends B

I have the ClassC object and trying to get fieldX via reflection.

Class partypes[] = new Class[0];
Object arglist[] = new Object[0];
Method getContextMethod = ClassC.class.getMethod("getFieldX",partypes);
String retValue =  (string) getContextMethod.invoke(classCInstance, arglist);

But I am getting NoSuchMethod exception.

I tried also reach the fieldX directly. But this time I am getting NoSuchField Exception.

Field reqField = ClassC.class.getDeclaredField("fieldX");
reqField.setAccessible(true);
Object value = reqField.get(classCInstance);
String retValue =  (string) value;

What is the thing I am doing wrong?
Is there a way to get this fieldX from ClassC object?

Solution: (thanks a lot vz0 for solution);

Direct access to private field:

Field reqField = ClassA.class.getDeclaredField("fieldX");
reqField.setAccessible(true);
String value = (String)reqField.get(clazzc);

Method Call;

Class partypes[] = new Class[0];
Object arglist[] = new Object[0];
Method getContextMethod = ClassA.class.getDeclaredMethod("getFieldX",partypes);
getContextMethod.setAccessible(true);
System.out.println((String)getContextMethod.invoke(clazzc, arglist));

Answer 1

The Class.getMethod call is for public methods only. You need to use the Class.getDeclaredMethod call and then setting the Method.setAccessible property to true:

Class partypes[] = new Class[0];
Object arglist[] = new Object[0];
Method getContextMethod = ClassA.class.getDeclaredMethod("getFieldX",partypes);

getContextMethod.setAccessible(true);

String retValue =  (string) getContextMethod.invoke(classCInstance, arglist);

EDIT: Since the getFieldX method is declared on ClassA, you need to fetch the Method from ClassA and not ClassC. As opposite to getMethod call, the getDeclaredMethod call ignores superclasses.