How to download mock from a file?

I have a Mock in Test that has JSON and it's big. How to load it from a file. Whether Mock should be in the resource directory or should it be in the test directory.

@ExtendWith(MockitoExtension.class)
class HubServiceTest {

    @InjectMocks
    private HubService hubService;

    @Mock
    private ConnectHttp connectHttp;
    private Controller controller;

    @Test
    public void shouldReturnCorrectRepositories() {

        when(connectHttp.connect(Mockito.any())).thenReturn("[\n" +
                "    {\n" +
                "        \"id\": 277322841,\n" +
                "        \"node_id\": \"MDEwOlJlcG9zaXRvcnkyNzczMjI4NDE=\",\n"}]")
<pre>  List<PojoGitHub> result = hubService.getRepositories("test");

        assertThat(result).isNotNull();
    }

I set it stiff in a mock