我已经搜索了一个答案，但是找不到。我对IntentService中的纬度和纬度进行反向地理编码，然后当我尝试ResultReceiver.send时会抛出nullpointerexception。我调试了参数，并像预期的那样包含了地址和结果代码。我搜索了所有未初始化的对象，但无法对其进行罚款。谁能告诉我发生了什么事吗？
这是对经纬度进行反向地理编码的方法。
@Override
public void onHandleIntent(Intent intent) {
// TODO Auto-generated method stub
Geocoder geocoder = new Geocoder(this, Locale.getDefault());
String errorMessage = "";
// Get the location passed to this service through an extra.
Location location = intent.getParcelableExtra(
Constants.LOCATION_DATA_EXTRA);
List<Address> addresses = null;
try {
addresses = geocoder.getFromLocation(
location.getLatitude(),
location.getLongitude(),
// In this sample, get just one addresse.
1);
} catch (IOException ioException) {
// Catch network or other I/O problems.
errorMessage = getString(R.string.service_not_available);
Log.e(TAG, errorMessage, ioException);
} catch (IllegalArgumentException illegalArgumentException) {
// Catch invalid latitude or longitude values.
errorMessage = getString(R.string.invalid_lat_lon);
Log.e(TAG, errorMessage + ". " +
"Latitude = " + location.getLatitude() +
", Longitude = " +
location.getLongitude(), illegalArgumentException);
}
// Handle case where no address was found.
if (addresses == null || addresses.size() == 0) {
if (errorMessage.isEmpty()) {
errorMessage = getString(R.string.no_address_found);
Log.e(TAG, errorMessage);
}
deliverResultToReceiver(Constants.FAILURE_RESULT, errorMessage);
} else if (!"".equals(addresses) || null != addresses || addresses.size() > 0) {
Address address = addresses.get(0);
ArrayList<String> addressFragments = new ArrayList<String>();
// Fetch the address lines using getAddressLine,
// join them, and send them to the thread.
for(int i = 0; i < address.getMaxAddressLineIndex(); i++) {
addressFragments.add(address.getAddressLine(i));
}
//Log.i(TAG, getString(R.string.no_address_found));
if (!TextUtils.isEmpty(String.valueOf(addressFragments)))
//this is the line number 95 mentioned in the logcat
deliverResultToReceiver(Constants.SUCCESS_RESULT, TextUtils.join(System.getProperty("line.separator"), addressFragments));
}
//GetAddressString(addresses);
//return st;
}
private void deliverResultToReceiver(int resultCode, String message) {
Bundle bundle = new Bundle();
try {
if (message != null || !"".equals(message))
bundle.putString(Constants.RESULT_DATA_KEY, message);
//this is line number 113 mentioned in the logcat
mReceiver.send(resultCode, bundle);
} catch (NullPointerException npe) {
// TODO Auto-generated catch block
npe.printStackTrace();
}
}
这是logcat
02-26 16:03:58.601: I/SELinux(7548): Function: selinux_android_load_priority [0], There is no sepolicy file.
02-26 16:03:58.601: I/SELinux(7548):
02-26 16:03:58.601: I/SELinux(7548): Function: selinux_android_load_priority [1], There is no sepolicy version file.
02-26 16:03:58.601: I/SELinux(7548):
02-26 16:03:58.601: I/SELinux(7548): Function: selinux_android_load_priority , priority version is VE=SEPF_SM-G800H_4.4.2_0018
02-26 16:03:58.601: I/SELinux(7548):
02-26 16:03:58.601: I/SELinux(7548):
02-26 16:03:58.601: I/SELinux(7548): selinux_android_seapp_context_reload: seapp_contexts file is loaded from /seapp_contexts
02-26 16:03:58.601: E/SELinux(7548): [DEBUG] seapp_context_lookup: seinfoCategory = default
02-26 16:03:58.601: E/dalvikvm(7548): >>>>> Normal User
02-26 16:03:58.601: E/dalvikvm(7548): >>>>> com.mypackage [ userId:0 | appId:10201 ]
02-26 16:03:58.621: E/SELinux(7548): [DEBUG] seapp_context_lookup: seinfoCategory = default
02-26 16:03:58.621: D/dalvikvm(7548): Late-enabling CheckJNI
02-26 16:03:58.671: D/TimaKeyStoreProvider(7548): in addTimaSignatureService
02-26 16:03:58.681: D/TimaKeyStoreProvider(7548): Cannot add TimaSignature Service, License check Failed
02-26 16:03:58.681: D/ActivityThread(7548): Added TimaKesytore provider
02-26 16:03:58.751: W/ActivityThread(7548): Application com.mypackage can be debugged on port 8100...
02-26 16:03:58.941: E/MoreInfoHPW_ViewGroup(7548): Parent view is not a TextView
02-26 16:03:59.001: I/x(7548): Making Creator dynamically
02-26 16:03:59.041: I/Google Maps Android API(7548): Google Play services client version: 6587000
02-26 16:03:59.051: I/Google Maps Android API(7548): Google Play services package version: 6776036
02-26 16:03:59.941: I/dalvikvm(7548): Could not find method android.content.pm.PackageManager.getPackageInstaller, referenced from method com.google.android.gms.common.ew.c
02-26 16:03:59.941: W/dalvikvm(7548): VFY: unable to resolve virtual method 441: Landroid/content/pm/PackageManager;.getPackageInstaller ()Landroid/content/pm/PackageInstaller;
02-26 16:03:59.941: D/dalvikvm(7548): VFY: replacing opcode 0x6e at 0x000f
02-26 16:03:59.981: W/ActivityThread(7548): ClassLoader.loadClass: The class loader returned by Thread.getContextClassLoader() may fail for processes that host multiple
applications. You should explicitly specify a context class loader. For example: Thread.setContextClassLoader(getClass().getClassLoader());
02-26 16:04:00.021: D/AbsListView(7548): Get MotionRecognitionManager
02-26 16:04:00.081: I/System.out(7548): Thread-618(HTTPLog):isShipBuild true
02-26 16:04:00.081: I/System.out(7548): Thread-618(HTTPLog):SmartBonding Enabling is false, SHIP_BUILD is true, log to file is false, DBG is false
02-26 16:04:00.221: I/Adreno-EGL(7548): <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: ()
02-26 16:04:00.221: I/Adreno-EGL(7548): OpenGL ES Shader Compiler Version: E031.24.00.08
02-26 16:04:00.221: I/Adreno-EGL(7548): Build Date: 03/21/14 Fri
02-26 16:04:00.221: I/Adreno-EGL(7548): Local Branch: AU200+patches_03212014
02-26 16:04:00.221: I/Adreno-EGL(7548): Remote Branch:
02-26 16:04:00.221: I/Adreno-EGL(7548): Local Patches:
02-26 16:04:00.221: I/Adreno-EGL(7548): Reconstruct Branch:
02-26 16:04:00.251: I/HWUI(7548): EGLImpl-HWUI Protected EGL context created
02-26 16:04:00.261: D/OpenGLRenderer(7548): Enabling debug mode 0
02-26 16:04:01.301: D/dalvikvm(7548): GC_FOR_ALLOC freed 17677K, 55% free 16268K/35592K, paused 55ms, total 55ms
02-26 16:04:03.161: D/dalvikvm(7548): GC_FOR_ALLOC freed 7882K, 54% free 16547K/35592K, paused 48ms, total 48ms
02-26 16:04:08.201: W/System.err(7548): java.lang.NullPointerException
02-26 16:04:08.201: W/System.err(7548): at com.mypackage.FetchAddressIntentService.deliverResultToReceiver(FetchAddressIntentService.java:113)
02-26 16:04:08.201: W/System.err(7548): at com.mypackage.FetchAddressIntentService.onHandleIntent(FetchAddressIntentService.java:95)
02-26 16:04:08.201: W/System.err(7548): at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:65)
02-26 16:04:08.201: W/System.err(7548): at android.os.Handler.dispatchMessage(Handler.java:102)
02-26 16:04:08.201: W/System.err(7548): at android.os.Looper.loop(Looper.java:146)
02-26 16:04:08.211: W/System.err(7548): at android.os.HandlerThread.run(HandlerThread.java:61)
最佳答案
之所以会得到空指针异常，是因为尚未实例化您创建的ResultReceiver。 Google在https://developer.android.com/training/location/display-address.html上的培训似乎并未专门解决此问题，但是，在请求“ FetchAddressIntentService”的应用程序的MainActivity中，您可以实例化ResultReceiver。
MainActivity.java
protected void startIntentService() {
Intent intent = new Intent(this, AddressIntentService.class);
mResultReceiver = new AddressResultReceiver(new Handler()); //instantiate here
intent.putExtra(RECEIVER, mResultReceiver);
intent.putExtra(LOCATION_DATA_EXTRA, mLastLocation);
startService(intent);
}
然后在FetchAddressIntentService.java中，将mResultReceiver项从意图包中提取出来，如下所示：
@Override
protected void onHandleIntent(Intent intent) {
Bundle parameters = intent.getExtras();
mReceiver = parameters.getParcelable(RECEIVER); }
重新运行代码，实例化后，空指针异常消失。