android - AmazonSNS - AwsCredentials.properties - NullPointerException

Question

我是 Android Studio 和 intelliJ 的新手。

我正在尝试使用 AmazonSNS - 推送。我无法弄清楚如何将 AwsCredentials.properties 文件添加到模块的类路径中。我在下图中的第 57 行(在方法 getResourceAsStream() 中)得到了一个 NPE。我在 AwsCredentials.properties 文件中添加了所需的 key 。

错误:

在我在 StackOverflow 上遇到的关于类似问题的问题中，有人建议该文件应位于根文件夹中，src 所在的文件夹中。我把它放在与 src 相同的文件夹中，但仍然得到 NPE。我也尝试将文件放在 com/test/中，但没有用。

我该如何解决这个问题？是否涉及任何其他步骤？

开始赏金后编辑 - 添加 java 文件

这是我到目前为止所做的..

1. 创建一个名为 MyApplication 的 Android 应用程序。从演示应用程序导入所有类(AndroidMobilePushApp.java、ExternalReceiver.java、MessageReceivingService.java)。添加所需的库，并运行它并获得 registationId 作为亚马逊的响应。

2. 在同一个应用程序中，我创建了一个名为 snspush 的新模块，并将 SNSMobilePush.java 文件导入其中。还将 AwsCredentials.properties 文件导入到与 SNSMobilePush.java 相同的路径。在 AwsCredentials.properties 文件中添加了 key 。

3. 按照文档中的步骤取消注释必要的功能。

项目结构:

Java 文件:

1. AndroidMobilePushApp.java:

   公共(public)类 AndroidMobilePushApp 扩展 AppCompatActivity { 私有(private) TextView tView； 私有(private) SharedPreferences savedValues； 私有(private)字符串 numOfMissedMessages;

   // Since this activity is SingleTop, there can only ever be one instance. This variable corresponds to this instance.
   public static Boolean inBackground = true;
   
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       numOfMissedMessages = getString(R.string.num_of_missed_messages);
       setContentView(R.layout.activity_main);
       tView = (TextView) findViewById(R.id.tViewId);
       tView.setMovementMethod(new ScrollingMovementMethod());
       startService(new Intent(this, MessageReceivingService.class));
   }
   
   public void onStop(){
       super.onStop();
       inBackground = true;
   }
   
   public void onRestart(){
       super.onRestart();
       tView.setText("");;
   }
   
   public void onResume(){
       super.onResume();
       inBackground = false;
       savedValues = MessageReceivingService.savedValues;
       int numOfMissedMessages = 0;
       if(savedValues != null){
           numOfMissedMessages = savedValues.getInt(this.numOfMissedMessages, 0);
       }
       String newMessage = getMessage(numOfMissedMessages);
       if(newMessage!=""){
           Log.i("displaying message", newMessage);
           tView.append(newMessage);
       }
   }
   
   public void onNewIntent(Intent intent){
       super.onNewIntent(intent);
       setIntent(intent);
   }
   
   // If messages have been missed, check the backlog. Otherwise check the current intent for a new message.
   private String getMessage(int numOfMissedMessages) {
       String message = "";
       String linesOfMessageCount = getString(R.string.lines_of_message_count);
       if(numOfMissedMessages > 0){
           String plural = numOfMissedMessages > 1 ? "s" : "";
           Log.i("onResume","missed " + numOfMissedMessages + " message" + plural);
           tView.append("You missed " + numOfMissedMessages +" message" + plural + ". Your most recent was:\n");
           for(int i = 0; i < savedValues.getInt(linesOfMessageCount, 0); i++){
               String line = savedValues.getString("MessageLine"+i, "");
               message+= (line + "\n");
           }
           NotificationManager mNotification = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
           mNotification.cancel(R.string.notification_number);
           SharedPreferences.Editor editor=savedValues.edit();
           editor.putInt(this.numOfMissedMessages, 0);
           editor.putInt(linesOfMessageCount, 0);
           editor.commit();
       }
       else{
           Log.i("onResume","no missed messages");
           Intent intent = getIntent();
           if(intent!=null){
               Bundle extras = intent.getExtras();
               if(extras!=null){
                   for(String key: extras.keySet()){
                       message+= key + "=" + extras.getString(key) + "\n";
                   }
               }
           }
       }
       message+="\n";
       return message;
   }
   
   public boolean onCreateOptionsMenu(Menu menu) {
       // Inflate the menu; this adds items to the action bar if it is present.
       getMenuInflater().inflate(R.menu.main, menu);
       return true;
   }
   
   public boolean onOptionsItemSelected(MenuItem item) {
       if(item.getItemId() == R.id.menu_clear){
           tView.setText("");
           return true;
       }
       else{
           return super.onOptionsItemSelected(item);
       }
   }
   

2. ExternalReceiver.java

   打包 com.test.awstestapp;

   导入android.content.BroadcastReceiver；导入 android.content.Context；导入 android.content.Intent；导入 android.os.Bundle;

   公共(public)类 ExternalReceiver 扩展 BroadcastReceiver {

   public void onReceive(Context context, Intent intent) {
       if(intent!=null){
           Bundle extras = intent.getExtras();
           if(!AndroidMobilePushApp.inBackground){
               MessageReceivingService.sendToApp(extras, context);
           }
           else{
               MessageReceivingService.saveToLog(extras, context);
           }
       }
   }
   

3. MessageReceivingService.java

公共(public)类 MessageReceivingService 扩展服务{ 私有(private) GoogleCloudMessaging gcm； public static SharedPreferences savedValues;

public static void sendToApp(Bundle extras, Context context){
    Intent newIntent = new Intent();
    newIntent.setClass(context, AndroidMobilePushApp.class);
    newIntent.putExtras(extras);
    newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(newIntent);
}

public void onCreate(){
    super.onCreate();
    final String preferences = getString(R.string.preferences);
    savedValues = getSharedPreferences(preferences, Context.MODE_PRIVATE);
    // In later versions multi_process is no longer the default
    if(VERSION.SDK_INT >  9){
        savedValues = getSharedPreferences(preferences, Context.MODE_MULTI_PROCESS);
    }
    gcm = GoogleCloudMessaging.getInstance(getBaseContext());
    SharedPreferences savedValues = PreferenceManager.getDefaultSharedPreferences(this);
    if(savedValues.getBoolean(getString(R.string.first_launch), true)){
        register();
        SharedPreferences.Editor editor = savedValues.edit();
        editor.putBoolean(getString(R.string.first_launch), false);
        editor.commit();
    }
    // Let AndroidMobilePushApp know we have just initialized and there may be stored messages
    sendToApp(new Bundle(), this);
}

protected static void saveToLog(Bundle extras, Context context){
    SharedPreferences.Editor editor=savedValues.edit();
    String numOfMissedMessages = context.getString(R.string.num_of_missed_messages);
    int linesOfMessageCount = 0;
    for(String key : extras.keySet()){
        String line = String.format("%s=%s", key, extras.getString(key));
        editor.putString("MessageLine" + linesOfMessageCount, line);
        linesOfMessageCount++;
    }
    editor.putInt(context.getString(R.string.lines_of_message_count), linesOfMessageCount);
    editor.putInt(context.getString(R.string.lines_of_message_count), linesOfMessageCount);
    editor.putInt(numOfMissedMessages, savedValues.getInt(numOfMissedMessages, 0) + 1);
    editor.commit();
    postNotification(new Intent(context, AndroidMobilePushApp.class), context);
}

protected static void postNotification(Intent intentAction, Context context){
    final NotificationManager mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

    final PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intentAction, Notification.DEFAULT_LIGHTS | Notification.FLAG_AUTO_CANCEL);
    final Notification notification = new NotificationCompat.Builder(context).setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle("Message Received!")
            .setContentText("")
            .setContentIntent(pendingIntent)
            .setAutoCancel(true)
            .getNotification();

    mNotificationManager.notify(R.string.notification_number, notification);
}

private void register() {
    new AsyncTask(){
        protected Object doInBackground(final Object... params) {
            String token;
            try {
                token = gcm.register(getString(R.string.project_number));
                Log.i("registrationId", token);
            } 
            catch (IOException e) {
                Log.i("Registration Error", e.getMessage());
            }
            return true;
        }
    }.execute(null, null, null);
}

public IBinder onBind(Intent arg0) {
    return null;
}

SNSMobilePush.java

包 com.test;

public class SNSMobilePush {

    private AmazonSNSClientWrapper snsClientWrapper;

    public SNSMobilePush(AmazonSNS snsClient) {
        this.snsClientWrapper = new AmazonSNSClientWrapper(snsClient);
    }

    public static final Map<Platform, Map<String, MessageAttributeValue>> attributesMap = new HashMap<Platform, Map<String, MessageAttributeValue>>();
    static {
        attributesMap.put(Platform.ADM, null);
        attributesMap.put(Platform.GCM, null);
        attributesMap.put(Platform.APNS, null);
        attributesMap.put(Platform.APNS_SANDBOX, null);
        attributesMap.put(Platform.BAIDU, addBaiduNotificationAttributes());
        attributesMap.put(Platform.WNS, addWNSNotificationAttributes());
        attributesMap.put(Platform.MPNS, addMPNSNotificationAttributes());
    }

    public static void main(String[] args) throws IOException {
        /*
         * TODO: Be sure to fill in your AWS access credentials in the
         * AwsCredentials.properties file before you try to run this sample.
         * http://aws.amazon.com/security-credentials
         */
        AmazonSNS sns = new AmazonSNSClient(new PropertiesCredentials(
                SNSMobilePush.class
                        .getResourceAsStream("AwsCredentials.properties")));

        sns.setEndpoint("https://sns.us-west-2.amazonaws.com");
        System.out.println("===========================================\n");
        System.out.println("Getting Started with Amazon SNS");
        System.out.println("===========================================\n");
        try {
            SNSMobilePush sample = new SNSMobilePush(sns);
            /* TODO: Uncomment the services you wish to use. */
            sample.demoAndroidAppNotification();
            // sample.demoKindleAppNotification();
            // sample.demoAppleAppNotification();
            // sample.demoAppleSandboxAppNotification();
            // sample.demoBaiduAppNotification();
            // sample.demoWNSAppNotification();
            // sample.demoMPNSAppNotification();
        } catch (AmazonServiceException ase) {
            System.out
                    .println("Caught an AmazonServiceException, which means your request made it "
                            + "to Amazon SNS, but was rejected with an error response for some reason.");
            System.out.println("Error Message:    " + ase.getMessage());
            System.out.println("HTTP Status Code: " + ase.getStatusCode());
            System.out.println("AWS Error Code:   " + ase.getErrorCode());
            System.out.println("Error Type:       " + ase.getErrorType());
            System.out.println("Request ID:       " + ase.getRequestId());
        } catch (AmazonClientException ace) {
            System.out
                    .println("Caught an AmazonClientException, which means the client encountered "
                            + "a serious internal problem while trying to communicate with SNS, such as not "
                            + "being able to access the network.");
            System.out.println("Error Message: " + ace.getMessage());
        }
    }

    public void demoAndroidAppNotification() {
        // TODO: Please fill in following values for your application. You can
        // also change the notification payload as per your preferences using
        // the method
        // com.amazonaws.sns.samples.tools.SampleMessageGenerator.getSampleAndroidMessage()
        String serverAPIKey = "REPLACED_WITH_SERVER_API_KEY";
        String applicationName = "snspushtest";
        String registrationId = "REPLACED_WITH_REG_ID_FROM_AMAZON";
        snsClientWrapper.demoNotification(Platform.GCM, "", serverAPIKey,
                registrationId, applicationName, attributesMap);
    }

    public void demoKindleAppNotification() {
        // TODO: Please fill in following values for your application. You can
        // also change the notification payload as per your preferences using
        // the method
        // com.amazonaws.sns.samples.tools.SampleMessageGenerator.getSampleKindleMessage()
        String clientId = "";
        String clientSecret = "";
        String applicationName = "";

        String registrationId = "";
        snsClientWrapper.demoNotification(Platform.ADM, clientId, clientSecret,
                registrationId, applicationName, attributesMap);
    }

    public void demoAppleAppNotification() {
        // TODO: Please fill in following values for your application. You can
        // also change the notification payload as per your preferences using
        // the method
        // com.amazonaws.sns.samples.tools.SampleMessageGenerator.getSampleAppleMessage()
        String certificate = ""; // This should be in pem format with \n at the
                                    // end of each line.
        String privateKey = ""; // This should be in pem format with \n at the
                                // end of each line.
        String applicationName = "";
        String deviceToken = ""; // This is 64 hex characters.
        snsClientWrapper.demoNotification(Platform.APNS, certificate,
                privateKey, deviceToken, applicationName, attributesMap);
    }

    public void demoAppleSandboxAppNotification() {
        // TODO: Please fill in following values for your application. You can
        // also change the notification payload as per your preferences using
        // the method
        // com.amazonaws.sns.samples.tools.SampleMessageGenerator.getSampleAppleMessage()
        String certificate = ""; // This should be in pem format with \n at the
                                    // end of each line.
        String privateKey = ""; // This should be in pem format with \n at the
                                // end of each line.
        String applicationName = "";
        String deviceToken = ""; // This is 64 hex characters.
        snsClientWrapper.demoNotification(Platform.APNS_SANDBOX, certificate,
                privateKey, deviceToken, applicationName, attributesMap);
    }

    public void demoBaiduAppNotification() {
        /*
         * TODO: Please fill in the following values for your application. If
         * you wish to change the properties of your Baidu notification, you can
         * do so by modifying the attribute values in the method
         * addBaiduNotificationAttributes() . You can also change the
         * notification payload as per your preferences using the method
         * com.amazonaws
         * .sns.samples.tools.SampleMessageGenerator.getSampleBaiduMessage()
         */
        String userId = "";
        String channelId = "";
        String apiKey = "";
        String secretKey = "";
        String applicationName = "";
        snsClientWrapper.demoNotification(Platform.BAIDU, apiKey, secretKey,
                channelId + "|" + userId, applicationName, attributesMap);
    }

    public void demoWNSAppNotification() {
        /*
         * TODO: Please fill in the following values for your application. If
         * you wish to change the properties of your WNS notification, you can
         * do so by modifying the attribute values in the method
         * addWNSNotificationAttributes() . You can also change the notification
         * payload as per your preferences using the method
         * com.amazonaws.sns.samples
         * .tools.SampleMessageGenerator.getSampleWNSMessage()
         */
        String notificationChannelURI = "";
        String packageSecurityIdentifier = "";
        String secretKey = "";
        String applicationName = "";
        snsClientWrapper.demoNotification(Platform.WNS,
                packageSecurityIdentifier, secretKey, notificationChannelURI,
                applicationName, attributesMap);
    }

    public void demoMPNSAppNotification() {
        /*
         * TODO: Please fill in the following values for your application. If
         * you wish to change the properties of your MPNS notification, you can
         * do so by modifying the attribute values in the method
         * addMPNSNotificationAttributes() . You can also change the
         * notification payload as per your preferences using the method
         * com.amazonaws
         * .sns.samples.tools.SampleMessageGenerator.getSampleMPNSMessage ()
         */
        String notificationChannelURI = "";
        String applicationName = "";
        snsClientWrapper.demoNotification(Platform.MPNS, "", "",
                notificationChannelURI, applicationName, attributesMap);
    }

    private static Map<String, MessageAttributeValue> addBaiduNotificationAttributes() {
        Map<String, MessageAttributeValue> notificationAttributes = new HashMap<String, MessageAttributeValue>();
        notificationAttributes.put("AWS.SNS.MOBILE.BAIDU.DeployStatus",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("1"));
        notificationAttributes.put("AWS.SNS.MOBILE.BAIDU.MessageKey",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("default-channel-msg-key"));
        notificationAttributes.put("AWS.SNS.MOBILE.BAIDU.MessageType",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("0"));
        return notificationAttributes;
    }

    private static Map<String, MessageAttributeValue> addWNSNotificationAttributes() {
        Map<String, MessageAttributeValue> notificationAttributes = new HashMap<String, MessageAttributeValue>();
        notificationAttributes.put("AWS.SNS.MOBILE.WNS.CachePolicy",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("cache"));
        notificationAttributes.put("AWS.SNS.MOBILE.WNS.Type",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("wns/badge"));
        return notificationAttributes;
    }

    private static Map<String, MessageAttributeValue> addMPNSNotificationAttributes() {
        Map<String, MessageAttributeValue> notificationAttributes = new HashMap<String, MessageAttributeValue>();
        notificationAttributes.put("AWS.SNS.MOBILE.MPNS.Type",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("token")); // This attribute is required.
        notificationAttributes.put("AWS.SNS.MOBILE.MPNS.NotificationClass",
                new MessageAttributeValue().withDataType("String")
                        .withStringValue("realtime")); // This attribute is required.

        return notificationAttributes;
    }
}

编辑 2:

编辑 3:

我将以下代码更改为:

AmazonSNS sns = new AmazonSNSClient(new PropertiesCredentials(
        SNSMobilePush.class
                .getResourceAsStream("AwsCredentials.properties")));

到

AmazonSNS sns = new AmazonSNSClient(new BasicAWSCredentials("ACCESS_KEY_REPLACED",
                "SECRET_KEY_REPLACED"));

现在，有一个不同的错误:Logcat

===========================================

Getting Started with Amazon SNS
===========================================

Exception in thread "main" java.lang.NoClassDefFoundError: org/xmlpull/v1/XmlPullParserException
    at com.amazonaws.services.sns.AmazonSNSClient.invoke(AmazonSNSClient.java:2263)
    at com.amazonaws.services.sns.AmazonSNSClient.createPlatformApplication(AmazonSNSClient.java:358)
    at com.test.tools.AmazonSNSClientWrapper.createPlatformApplication(AmazonSNSClientWrapper.java:49)
    at com.test.tools.AmazonSNSClientWrapper.demoNotification(AmazonSNSClientWrapper.java:119)
    at com.test.SNSMobilePush.demoAndroidAppNotification(SNSMobilePush.java:104)
    at com.test.SNSMobilePush.main(SNSMobilePush.java:71)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.ClassNotFoundException: org.xmlpull.v1.XmlPullParserException
    at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 11 more

Process finished with exit code 1

Answer 1

我正在使用 sns v2.2.5 :

build.gradle > compile 'com.amazonaws:aws-android-sdk-sns:2.2.5'

这是我的订阅/取消订阅解决方案:

public class AmazonPushClient {

private static final String TAG = "AmazonPushClient";

private static final String PLATFORM_APPLICATION_ARN = "*****";
private static final String IDENTITY_POOL_ID = "******";

private AmazonSNSClient mClient;
private boolean isUnregistering;
private Application mApp;
private NotifPreferencesHelper mNotifPreferencesHelper;

public AmazonPushClient(Application application) {
    try {
        mApp = application;
        mClient = createPushClient(application);
        mNotifPreferencesHelper = new NotifPreferencesHelper(application);
    } catch (Exception e) {
        LOGE(TAG, "AmazonPushClient", e);
    }
}

@Nullable
private String token() {
    try {
        return InstanceID.getInstance(mApp).getToken(mApp.getString(R.string.gcm_defaultSenderId),
                GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);
    } catch (Exception e) {
        LOGW(TAG, "token", e);
        return null;
    }
}

private CognitoCachingCredentialsProvider cognitoCachingCredentialsProvider(Application application) {
    return new CognitoCachingCredentialsProvider(
            application,
            IDENTITY_POOL_ID,
            Regions.EU_WEST_1 // if your identity_pool_id start with : eu-west-1
    );
}

private AmazonSNSClient createPushClient(Application application) {
    AmazonSNSClient client = new AmazonSNSClient(cognitoCachingCredentialsProvider(application));
    client.setRegion(Region.getRegion(Regions.EU_WEST_1));
    client.addRequestHandler(mHandler);
    return client;
}

public void pRegister() {
    synchronized (TAG) {
        LOGD(TAG, "registering");
        isUnregistering = true;
        String token = token();
        if(TextUtils.isEmpty(token)) {
            return;
        }
        mNotifPreferencesHelper.saveNotificationPreferences(true);
        CreatePlatformEndpointRequest platformEndpointRequest = new CreatePlatformEndpointRequest();
        platformEndpointRequest.setToken(token());
        platformEndpointRequest.setPlatformApplicationArn(PLATFORM_APPLICATION_ARN);
        CreatePlatformEndpointResult result = mClient.createPlatformEndpoint(platformEndpointRequest);
        mNotifPreferencesHelper.storeEndpointArn(result.getEndpointArn());
    }
}

public void pUnregister() {
    synchronized (TAG) {
        LOGD(TAG, "unregistering");
        isUnregistering = false;
        mNotifPreferencesHelper.saveNotificationPreferences(false);
        DeleteEndpointRequest deletePlatformApplicationRequest = new DeleteEndpointRequest();
        deletePlatformApplicationRequest.setEndpointArn(mNotifPreferencesHelper.getEndpointArn());
        mClient.deleteEndpoint(deletePlatformApplicationRequest);
    }
}

private RequestHandler2 mHandler = new RequestHandler2() {
    @Override
    public void beforeRequest(Request<?> request) {

    }

    @Override
    public void afterResponse(Request<?> request, Response<?> response) {
        if (isUnregistering) {
            mNotifPreferencesHelper.storeEndpointArn(null);
        }
    }

    @Override
    public void afterError(Request<?> request, Response<?> response, Exception e) {
    }
};

}

NotifPreferencesHelper 只是用来存储 EndpointARN 的东西。你必须在后台线程中使用这个类

在关联中，您必须实现 GcmListenerService 等。SNS 仅用于订阅，而不是接收。 https://developers.google.com/cloud-messaging/