Why Android service crashes with NullPointerException?

问题

Here is the code:

public class BillingService extends Service implements ServiceConnection {
...
    @Override
    public void onStart(Intent intent, int startId) {
        handleCommand(intent, startId); // line 361
    }

    /**
     * The {@link BillingReceiver} sends messages to this service using intents.
     * Each intent has an action and some extra arguments specific to that action.
     * @param intent the intent containing one of the supported actions
     * @param startId an identifier for the invocation instance of this service
     */
    public void handleCommand(Intent intent, int startId) {
        String action = intent.getAction();
        if (Debug.Yes) {
            Log.i(TAG, "handleCommand() action: " + action);
        }
        if (Consts.ACTION_CONFIRM_NOTIFICATION.equals(action)) {
            String[] notifyIds = intent.getStringArrayExtra(Consts.NOTIFICATION_ID);
            confirmNotifications(startId, notifyIds);
        } else if (Consts.ACTION_GET_PURCHASE_INFORMATION.equals(action)) {
            String notifyId = intent.getStringExtra(Consts.NOTIFICATION_ID);
            getPurchaseInformation(startId, new String[] { notifyId });
        } else if (Consts.ACTION_PURCHASE_STATE_CHANGED.equals(action)) {
            String signedData = intent.getStringExtra(Consts.INAPP_SIGNED_DATA);
            String signature = intent.getStringExtra(Consts.INAPP_SIGNATURE);
            purchaseStateChanged(startId, signedData, signature);
        } else if (Consts.ACTION_RESPONSE_CODE.equals(action)) {
            long requestId = intent.getLongExtra(Consts.INAPP_REQUEST_ID, -1);
            int responseCodeIndex = intent.getIntExtra(Consts.INAPP_RESPONSE_CODE,
                    ResponseCode.RESULT_ERROR.ordinal());
            ResponseCode responseCode = ResponseCode.valueOf(responseCodeIndex);
            checkResponseCode(requestId, responseCode);
        }
    }

Here is the LogCat:

java.lang.RuntimeException: Unable to start service tv.kinobaza.billing.BillingService@45129a30 with null: java.lang.NullPointerException
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3063)
at android.app.ActivityThread.access$3600(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2096)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:876)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at tv.kinobaza.billing.BillingService.onStart(BillingService.java:361)
at android.app.Service.onStartCommand(Service.java:420)
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3053)
... 10 more

回答1:

I believe the most likely cause would be because intent would be null. According to the documentation for onStartCommand:

intent

The Intent supplied to startService(Intent), as given. This may be null if the service is being restarted after its process has gone away, and it had previously returned anything except START_STICKY_COMPATIBILITY

回答2:

@Override
public void onStart(Intent intent, int startId) {
    handleCommand(intent, startId);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    handleCommand(intent, startId);
    return START_NOT_STICKY;
}

来源：https://stackoverflow.com/questions/5856861/why-android-service-crashes-with-nullpointerexception