unit testing using junit,mokito

i am new to unit testing, and i stuck while testing a spring mvc controller using junit,mockito which gets a data from data base. Here is my spring mvc controller code:

@RequestMapping(value="/getdata" , method=RequestMethod.GET)
    public   List<Components> listContact(ModelAndView model) throws IOException{
        System.out.println("i made a call");
        List<Components> listContact;
        listContact= exampeldao.list();


        System.out.println("hiii i made a call  but i dnt have any data.....");

        return listContact;

    }

i can able to make a call from test code to "/getdata" uri, but i could not able to execute listContact= exampeldao.list(); statement. i have defined list() in some other class.

here is my test code:

public class RestTest {
  @InjectMocks
  ComponentController contrller;
  @Mock
  Example exampleda;

private MockMvc mockMvc;




@Autowired
DataSource dataSource;

 @Autowired
    private Example exampledao;
 @Autowired
    private WebApplicationContext webApplicationContext;
 @Before
    public void setUp() {

        Mockito.reset(exampledao);

        mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
    }
@Test
public void findAllObjects() throws Exception

{
    Components first = new TodoBuilder()
    .cname("asdfasf")
    .mdesc("asdcb")
    .cdesc("asdfa")
    .ccode("asdf")
    .unitrateusd(24)
    .build();

    when(exampledao.list()).thenReturn(Arrays.asList(first));
    mockMvc.perform(get("/getdata"))
    .andExpect(status().isOk())


    .andExpect(content().contentType(TestUtil.APPLICATION_JSON))
   .andExpect(jsonPath("$", hasSize(0)))

     .andExpect(jsonPath("$[0].cname", is("asdfasf")))
     .andExpect(jsonPath("$[0].mdesc", is("asdcb")))
     .andExpect(jsonPath("$[0].cdesc", is("asdfa")))
      .andExpect(jsonPath("$[0].ccode", is("asdf")))
      .andExpect(jsonPath("$[0].unitrateusd", is(24)));
      }

and when i run unit test i am getting a SecurityException:org.hamcrest.Matchers signature information does not match wit signature of other classes in same package...

any one help me to sort out this issue

Thanks