Question

我是android新手，所以学习AsyncTask库。我想在AsyncTask中对用户联系人列表执行操作。因为这是一个漫长的过程，我不希望用户等到它完成。但每当我运行它，它关闭我的应用程序，不调用getContentResolver方法，我的AsyncTask方法工作正常。我不知道我的getContentResolver方法有什么问题。

我的AsyncTask文件是，

public class clsAsyncTask extends AsyncTask<TextView, String, Boolean> {

    TextView txtView;
    Boolean finalStatus = false;
    @Override
    protected Boolean doInBackground(TextView... params) {

        if(params.length > 0){
            txtView = params[0];
            saveContacts contacts = new saveContacts("");
            contacts.onHandleIntent(new Intent());
            publishProgress("Step 2 cleared");
            finalStatus = true;
        }
        return finalStatus;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(Boolean aBoolean) {
        if(aBoolean){
            publishProgress("All cleared");
        }else{
            publishProgress("Error accured");
        }
    }

    @Override
    protected void onProgressUpdate(String... values) {
        txtView.setText(values[0]);
    }
}

我的getContentResolver文件是，

public class saveContacts extends IntentService {

    public saveContacts(String name) {
        super(name);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        StringBuffer sb = new StringBuffer();
        sb.append("......Contact Details.....");

        String name = "";
        String phoneNumber="";
        String emailId = "";
        Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, null);
        sb.append("total = " + phones.getCount());
        while (phones.moveToNext())
        {
            name=phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
            phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
            sb.append("\nEmail: " + name + " phoneNumber: " + phoneNumber);

        }
        phones.close();

    }
}

我的主要活动是调用Async方法，如下所示，

public class MainActivity extends ActionBarActivity {

    TextView txtView;
    clsAsyncTask _AsyncTaskWorker;
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        txtView = (TextView) findViewById(R.id.txt_view);

        txtView.setText("Execution start");
        _AsyncTaskWorker = new clsAsyncTask();
        _AsyncTaskWorker.execute(txtView);
    }
}

Logcat错误部分，它显示如下，

07-11 09:02:24.630      664-705/? E/ElectronBeam﹕ Can not update rotation!
07-11 09:02:24.946      664-705/? E/ElectronBeam﹕ Can not update rotation!
07-11 09:02:26.295    4384-4384/? E/InitDefaultSoftInfo﹕ i=1defaultresolveinfo.size():2
07-11 09:02:26.295    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:26.327      735-735/? E/KeyguardUpdateMonitor﹕ Object tried to add another callback
    java.lang.Exception: Called by
            at com.android.keyguard.KeyguardUpdateMonitor.registerCallback(KeyguardUpdateMonitor.java:1176)
            at com.android.keyguard.KeyguardSelectorView.onResume(KeyguardSelectorView.java:397)
            at com.android.keyguard.KeyguardHostView.onScreenTurnedOn(KeyguardHostView.java:1311)
            at com.android.keyguard.KeyguardViewManager.onScreenTurnedOn(KeyguardViewManager.java:576)
            at com.android.keyguard.KeyguardViewMediator.handleNotifyScreenOn(KeyguardViewMediator.java:1933)
            at com.android.keyguard.KeyguardViewMediator.access$2500(KeyguardViewMediator.java:132)
            at com.android.keyguard.KeyguardViewMediator$4.handleMessage(KeyguardViewMediator.java:1539)
            at android.os.Handler.dispatchMessage(Handler.java:110)
            at android.os.Looper.loop(Looper.java:193)
            at android.app.ActivityThread.main(ActivityThread.java:5341)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:830)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:646)
            at dalvik.system.NativeStart.main(Native Method)
07-11 09:02:26.343    4384-4384/? E/InitDefaultSoftInfo﹕ i=2defaultresolveinfo.size():3
07-11 09:02:26.343    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:26.351    4384-4384/? E/InitDefaultSoftInfo﹕ i=3defaultresolveinfo.size():4
07-11 09:02:26.351    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:26.356      664-664/? E/﹕ Could not open '/data/data/hotplug/cmd'
07-11 09:02:26.356      664-664/? E/﹕ error : 2, No such file or directory
07-11 09:02:26.440    4384-4384/? E/InitDefaultSoftInfo﹕ i=4defaultresolveinfo.size():5
07-11 09:02:26.440    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:26.700    4384-4384/? E/InitDefaultSoftInfo﹕ i=6defaultresolveinfo.size():7
07-11 09:02:26.700    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:26.814    4384-4384/? E/InitDefaultSoftInfo﹕ i=7defaultresolveinfo.size():8
07-11 09:02:26.814    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:26.944    143-30185/? E/AudioMTKHardware﹕ setCommonParameters() still have param.size() = 1, remain param = "screen_state=on"
07-11 09:02:28.333      664-664/? E/RemoteViews﹕ ANR Warning,RemoteViews can only be used once ,if not ,it may cause ANR in hosts such as Laucher,SystemUI. keys for search <ANR Exception MSG   History>
07-11 09:02:28.802     858-1274/? E/CellLocation﹕ create GsmCellLocation
07-11 09:02:29.049     858-1274/? E/CellLocation﹕ create GsmCellLocation
07-11 09:02:29.514     973-1156/? E/ActivityThread﹕ Failed to find provider info for com.gionee.account
07-11 09:02:30.202  16221-16221/? E/PhotosPlugin﹕ Loading PhotosPlugin
07-11 09:02:31.962      143-516/? E/﹕ AudioCloseDumpPCMFile file== NULL
07-11 09:02:31.962      143-516/? E/﹕ AudioCloseDumpPCMFile file== NULL
07-11 09:02:31.962      143-516/? E/﹕ AudioCloseDumpPCMFile file== NULL
07-11 09:02:31.962      143-516/? E/﹕ AudioCloseDumpPCMFile file== NULL
07-11 09:02:32.476  16165-16241/keval.asynctask E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
    Process: keval.asynctask, PID: 16165
    java.lang.RuntimeException: An error occured while executing doInBackground()
            at android.os.AsyncTask$3.done(AsyncTask.java:300)
            at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
            at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
            at java.util.concurrent.FutureTask.run(FutureTask.java:242)
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:841)
     Caused by: java.lang.NullPointerException
            at android.content.ContextWrapper.getContentResolver(ContextWrapper.java:99)
            at keval.asynctask.saveContacts.onHandleIntent(saveContacts.java:26)
            at keval.asynctask.clsAsyncTask.doInBackground(clsAsyncTask.java:24)
            at keval.asynctask.clsAsyncTask.doInBackground(clsAsyncTask.java:14)
            at android.os.AsyncTask$2.call(AsyncTask.java:288)
            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:841)
07-11 09:02:32.501  16165-16165/keval.asynctask E/﹕ appName=keval.asynctask, acAppName=/system/bin/surfaceflinger
07-11 09:02:32.501  16165-16165/keval.asynctask E/﹕ 0
07-11 09:02:32.501  16165-16165/keval.asynctask E/﹕ appName=keval.asynctask, acAppName=/system/bin/surfaceflinger
07-11 09:02:32.501  16165-16165/keval.asynctask E/﹕ 0
07-11 09:02:32.889      664-684/? E/﹕ Could not open '/data/data/hotplug/cmd'
07-11 09:02:32.889      664-684/? E/﹕ error : 2, No such file or directory
07-11 09:02:33.077    4384-4384/? E/InitDefaultSoftInfo﹕ i=1defaultresolveinfo.size():2
07-11 09:02:33.077    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:33.093    4384-4384/? E/InitDefaultSoftInfo﹕ i=2defaultresolveinfo.size():3
07-11 09:02:33.093    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:33.095    4384-4384/? E/InitDefaultSoftInfo﹕ i=3defaultresolveinfo.size():4
07-11 09:02:33.095    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:33.096    4384-4384/? E/InitDefaultSoftInfo﹕ i=4defaultresolveinfo.size():5
07-11 09:02:33.096    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:33.141    4384-4384/? E/InitDefaultSoftInfo﹕ i=6defaultresolveinfo.size():7
07-11 09:02:33.141    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:33.163    4384-4384/? E/InitDefaultSoftInfo﹕ i=7defaultresolveinfo.size():8
07-11 09:02:33.163    4384-4384/? E/InitDefaultSoftInfo﹕ best != null
07-11 09:02:33.496      664-944/? E/﹕ Could not open '/data/data/hotplug/cmd'
07-11 09:02:33.496      664-944/? E/﹕ error : 2, No such file or directory
07-11 09:02:35.064  16307-16323/? E/chromium_android_linker﹕ UseSharedRelro: Could not use shared RELRO for libchrome.so: No pages were swapped into RELRO ashmem
07-11 09:02:35.131  16307-16323/? E/﹕ appName=com.android.chrome:privileged_process0, acAppName=/system/bin/surfaceflinger
07-11 09:02:35.131  16307-16323/? E/﹕ 0
07-11 09:02:35.131  16307-16323/? E/﹕ appName=com.android.chrome:privileged_process0, acAppName=/system/bin/surfaceflinger
07-11 09:02:35.131  16307-16323/? E/﹕ 0
07-11 09:02:35.229    1003-1003/? E/NetworkScheduler.SchedulerReceiver﹕ Invalid parameter app
07-11 09:02:35.229    1003-1003/? E/NetworkScheduler.SchedulerReceiver﹕ Invalid package name : Perhaps you didn't include a PendingIntent in the extras?
07-11 09:02:35.300  16307-16323/? E/﹕ appName=com.android.chrome:privileged_process0, acAppName=/system/bin/surfaceflinger
07-11 09:02:35.301  16307-16323/? E/﹕ 0
07-11 09:02:35.301  16307-16323/? E/﹕ appName=com.android.chrome:privileged_process0, acAppName=/system/bin/surfaceflinger
07-11 09:02:35.301  16307-16323/? E/﹕ 0
07-11 09:02:35.325  16307-16323/? E/﹕ appName=com.android.chrome:privileged_process0, acAppName=/system/bin/surfaceflinger
07-11 09:02:35.325  16307-16323/? E/﹕ 0
07-11 09:02:35.325  16307-16323/? E/﹕ appName=com.android.chrome:privileged_process0, acAppName=/system/bin/surfaceflinger
07-11 09:02:35.325  16307-16323/? E/﹕ 0
07-11 09:02:36.016  16370-16370/? E/﹕ appName=com.google.android.apps.magazines, acAppName=/system/bin/surfaceflinger
07-11 09:02:36.016  16370-16370/? E/﹕ 0
07-11 09:02:36.016  16370-16370/? E/﹕ appName=com.google.android.apps.magazines, acAppName=/system/bin/surfaceflinger
07-11 09:02:36.016  16370-16370/? E/﹕ 0
07-11 09:02:36.791  16422-16440/? E/NativeCrypto﹕ ssl=0x607e57a8 cert_verify_callback x509_store_ctx=0x610ad8c0 arg=0x0
07-11 09:02:36.791  16422-16440/? E/NativeCrypto﹕ ssl=0x607e57a8 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_RSA
07-11 09:02:36.813  16470-16470/? E/dalvikvm﹕ Could not find class 'com.amazon.device.messaging.ADM', referenced from method com.appboy.Appboy.<init>
07-11 09:02:37.291     664-1595/? E/ActivityManager﹕ Service ServiceRecord{42d9f2b0 u0 com.google.android.youtube/com.google.android.apps.youtube.app.offline.transfer.OfflineTransferService} in process ProcessRecord{42c8a980 15786:com.google.android.youtube/u0a91} not same as in map: null
07-11 09:02:37.348  16470-16542/? E/NativeCrypto﹕ ssl=0x62875cc0 cert_verify_callback x509_store_ctx=0x6274a940 arg=0x0
07-11 09:02:37.348  16470-16542/? E/NativeCrypto﹕ ssl=0x62875cc0 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_RSA
07-11 09:02:37.453    1003-1003/? E/AuthorizationBluetoothService﹕ Proximity feature is not enabled.
07-11 09:02:37.456  16470-16532/? E/NativeCrypto﹕ ssl=0x629948f8 cert_verify_callback x509_store_ctx=0x623a1940 arg=0x0
07-11 09:02:37.456  16470-16532/? E/NativeCrypto﹕ ssl=0x629948f8 cert_verify_callback calling verifyCertificateChain authMethod=RSA
07-11 09:02:37.482  16470-16529/? E/NativeCrypto﹕ ssl=0x628abbb0 cert_verify_callback x509_store_ctx=0x6203e940 arg=0x0
07-11 09:02:37.483  16470-16529/? E/NativeCrypto﹕ ssl=0x628abbb0 cert_verify_callback calling verifyCertificateChain authMethod=RSA
07-11 09:02:37.526  16294-16294/? E/dalvikvm﹕ Could not find class 'android.telecom.TelecomManager', referenced from method com.google.android.gms.wearable.service.y.a
07-11 09:02:37.603     858-2870/? E/MDM﹕ [67] b.run: Couldn't connect to Google API client: ConnectionResult{statusCode=API_UNAVAILABLE, resolution=null}
07-11 09:02:38.568  16572-16572/? E/dalvikvm﹕ Could not find class 'android.app.Notification$Action$Builder', referenced from method b.a
07-11 09:02:38.584  16572-16572/? E/dalvikvm﹕ Could not find class 'al', referenced from method b.a
07-11 09:02:38.586  16572-16572/? E/dalvikvm﹕ Could not find class 'an', referenced from method b.a
07-11 09:02:38.592  16572-16572/? E/dalvikvm﹕ Could not find class 'android.app.RemoteInput[]', referenced from method b.a
07-11 09:02:38.871  16572-16572/? E/WifiManager﹕ mWifiServiceMessenger == null
07-11 09:02:39.316  16572-16572/? E/WifiManager﹕ mWifiServiceMessenger == null
07-11 09:02:42.352  16422-16422/? E/ActivityThread﹕ Failed to find provider info for com.facebook.katana.provider.AttributionIdProvider
07-11 09:02:42.366  16422-16663/? E/ActivityThread﹕ Failed to find provider info for com.facebook.katana.provider.AttributionIdProvider
07-11 09:02:42.546  16422-16439/? E/NativeCrypto﹕ ssl=0x607e3ed0 cert_verify_callback x509_store_ctx=0x60f6f940 arg=0x0
07-11 09:02:42.547  16422-16439/? E/NativeCrypto﹕ ssl=0x607e3ed0 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_ECDSA
07-11 09:02:58.108    143-17153/? E/AudioMTKHardware﹕ setCommonParameters() still have param.size() = 1, remain param = "screen_state=off"
07-11 09:02:59.036     973-1156/? E/ActivityThread﹕ Failed to find provider info for com.gionee.account
07-11 09:03:00.337      664-664/? E/RemoteViews﹕ ANR Warning,RemoteViews can only be used once ,if not ,it may cause ANR in hosts such as Laucher,SystemUI. keys for search <ANR Exception MSG   History>
07-11 09:03:03.056      735-735/? E/KeyguardHostView﹕ KeyguardHostView()

我已在联系人和联系人阅读清单文件中添加了所有权限。

请告诉我需要做些什么改变才能让它发挥作用。

谢谢。

Answer 1

您正在获取NPE（又名NullPointerException），因为您手动创建了一个不好的IntentService：saveContacts contacts = new saveContacts("");

这是使用IntentServices的tutorial。

或者在您的情况下，将代码移出onHandleIntent并将其直接放入doInBackground可能是有意义的。

带有AsyncTask的getContentResolver

1 个答案: