为什么 Android 服务会因 NullPointerException 崩溃？

Question

这是代码：

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);
        }
    }

这是 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

Answer 1

我相信最可能的原因是 intent 为 null。根据 onStartCommand：

意图

提供给 startService(Intent) 的 Intent，如给定的。如果服务在其进程消失后重新启动，并且之前返回了除 START_STICKY_COMPATIBILITY

之外的任何内容，则该值可能为 null

Answer 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;
}