EasyMock: Getting NullPointerException while calling super class method

Question

I am using EasyMock, after debug, I found that the issue is in A.java > while calling getResults(val) from dbconnection object.

dbconnection object is null, my question is how to Mock the objects in super class ?

Here is the simple code:

A.java

public class A {

    @Autowired
    DataBaseConnection dbconnection;

    public Result methodInA(String val)() {
        result = new Result();
        result = dbconnection.getResults(val);  
        return result;
    };
}

B.java

public class B extends A {

    public Fresult getfinalResult(String value) {

        // Fresult class contains 'Result' class object and some other variables
        Fresult fresult = new Fresult();
        // some logic here...and I was able to exeduted this by creating mocks in my test class...    
        Result result = methodInA(val); 
        fresult.setResult(result);
        return fresult;
    }   
}

BTest.java

@Before
public void setUp(){
   A objectA = new A();
   dbconnection = createMock( DataBaseConnection.class );
   setField( objectA, "dbconnection", dbconnection );
   expect( dbconnection.getResults( EasyMock.anyObject( String.class ) ) ).andReturn( 'Dummy Result object' ).anyTimes();
}

@Test
public void methodName() {
    B classBobject = new B();
    replayAll();
    Fresult fresult  = classBobject.getfinalResult("some value");
    verifyAll();
    assertEquals("Somthing", "Somtthing");
}