Mocking private memebers

Calculator.java

public class Calculator {
	private DAO dao;

	public int add() {
		dao = new DAO();
		return dao.getA() + dao.getB();
	}

}

CalculatorTest.java

import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.when;
import static org.powermock.api.mockito.PowerMockito.whenNew;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest({ Calculator.class })
public class CalculatorTest {
	@Mock
	private DAO mydao;
	@InjectMocks Calculator cal;

	@Test
	public void testAdd() throws Exception {
		
		when(mydao.getA()).thenReturn(4);
		when(mydao.getB()).thenReturn(5);
		whenNew(DAO.class).withNoArguments().thenReturn(mydao);

		assertEquals(9, cal.add());
	}

}

DAO.java

public class DAO {
	public int getA() {
		return 1;
	}
	
	public int getB() {
		return 2;
	}
}

pom_dependencies.xml

	<dependencies>
		<dependency>
			<groupId>org.powermock</groupId>
			<artifactId>powermock-api-mockito</artifactId>
			<version>1.5.6</version>
		</dependency>

		<dependency>
			<groupId>org.powermock</groupId>
			<artifactId>powermock-module-junit4</artifactId>
			<version>1.5.6</version>
		</dependency>

		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.10</version>
		</dependency>

	</dependencies>