Mockito

Dans Unit Test
============================================
Database
============================================
public class Database {

    public boolean isAvailable() {
        // currently not implemented, as this is just demo used in a software test
        return false;
    }
    public int getUniqueId() {
        return 42;
    }
}
============================================
Service
============================================
public class Service {

    private Database database;

    public Service(Database database) {
        this.database = database;
    }

    public boolean query(String query) {
        return database.isAvailable();
    }


    @Override
    public String toString() {
        return "Using database with id: " + String.valueOf(database.getUniqueId());
    }
}
============================================
ExampleUnitTest
============================================


@RunWith(MockitoJUnitRunner.class)
public class ExampleUnitTest {

        @Mock
        Database databaseMock;


        @Test
        public void testQuery()  {

            assertNotNull(databaseMock);
            when(databaseMock.isAvailable()).thenReturn(true);
            Service t  = new Service(databaseMock);
            boolean check = t.query("* from t");
            assertThat(check, equalTo(true));


        }
     @Test
     public void ensureMockitoReturnsTheConfiguredValue() {

        // define return value for method getUniqueId()
        when(databaseMock.getUniqueId()).thenReturn(42);

        Service service = new Service(databaseMock);
        // use mock in test....
        assertEquals(service.toString(), "Using database with id: 42");
     }
    }