Question

我正在使用一个简单的代码并不断获得

java.lang.NullPointerException：侦听器不能为空

我仅使用非常简短的代码来尝试获取当前位置，但无法正常工作。它可能必须与@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes={rtyuuu.class}) public class UserControllerIntegrationTest { private MockMvc mockMvc; @Mock private SignOnService signOnService; @Mock public PersonService personService; @Mock public CustomerService customerService; @Mock private AgreementService agreementService; @Mock private DisbursementConfigService disbursementConfigService; @Mock private SignOnRqValidator signOnRqValidator; @Mock private ValidateTokenRqValidator validateTokenRqValidator; @Mock private ValidateTokenService validateTokenService; @InjectMocks private UserController userController; private static final String BASE_URI = "http://fhrfbg78:7001/disbursementServices/v1/users/signOn"; private WebApplicationContext wac; @Before public void init(){ MockitoAnnotations.initMocks(this); mockMvc = MockMvcBuilders .standaloneSetup(userController) .build(); } @Test public void testPost() throws Exception { SignOnRq signOnRq = new SignOnRq(); signOnRq.setPassword("abc"); signOnRq.setUserName("abc"); SignOnRq signOnRq1 = new SignOnRq(); signOnRq.setPassword("abc"); signOnRq.setUserName("abc"); signOnRq.setCorrelationId("665356"); signOnRq.setResponseId("79368700"); Gson gson = new Gson(); String jsonString = gson.toJson(signOnRq); BindingResult result = mock(BindingResult.class); mockMvc.perform(post(BASE_URI) .header("homeId", "88851153") .header("ipAddress", "10.10.19.10") .header("correlationId", "665656") .header("X-Fiserv-UserAgent", "DISB.API.1.0") .contentType(MediaType.APPLICATION_JSON_VALUE) .content(jsonString)) .andExpect(status().isOk()); } }回调中循环程序位置的“ null”有关。但我不确定。我已经整天都在尝试。

这是短代码：

requestLocationUpdates

我只想简单地获取当前位置，那为什么给我这么难过呢？是什么导致此错误？

谢谢

Answer 1

您正在尝试使用mLocationCallback进行初始化。只需移动此代码即可：

mLocationCallback = new LocationCallback() {
        @Override
        public void onLocationResult(LocationResult locationResult) {
            if (locationResult == null) {
                return;
            }
            for (Location location : locationResult.getLocations()) {
                // Update UI with location data
                TextView tv = (TextView) findViewById(R.id.tv);
                Double latDouble = location.getLatitude();
                String latString = latDouble.toString();
                tv.setText(latString);
            }
        };
    };

在此之前：

if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {
        //
    } else {
        mFusedLocationClient.requestLocationUpdates(mLocationRequest, mLocationCallback,
                null /* Looper */);
    }

Looper线程中的null与它无关。通过将其传递为null，可以将回调保留在调用线程上。

Google Location API问题

1 个答案: