title: Null error loading user with DynamoDB (Android)
body: <p>I'm attempting create my first dynamodb app on android and get receiving a null-pointer error that I can not figure out why.</p>
  
  <p>I've written the following asyntask:</p>
  
  <pre><code>class CheckIfEmailNull extends AsyncTask&lt;String, Void, Void&gt;{
  
          DynamoDBMapper dynamoDBMapper;
  
  
          @Override
          protected Void doInBackground(String... userID) {
  
              AmazonDynamoDBClient dynamoDBClient = new AmazonDynamoDBClient(AWSMobileClient.getInstance().getCredentialsProvider());
              this.dynamoDBMapper = DynamoDBMapper.builder()
                      .dynamoDBClient(dynamoDBClient)
                      .awsConfiguration(AWSMobileClient.getInstance().getConfiguration())
                      .build();
  
              userB = dynamoDBMapper.load(SecureUsersDO.class, userID[0]);
              return null;
          }
      }
  </code></pre>
  
  <p>With the following method to written to initiate it:</p>
  
  <pre><code>public void checkUserEmail(Profile profileTest){
  
          Log.d("checkUserEmail&gt;&gt;&gt;", profileTest.getId().toString());
  
          CheckIfEmailNull checkIfEmailNull = new CheckIfEmailNull();
          checkIfEmailNull.execute(profileTest.getId().toString());
  
          if (userB.getUserId() == profileTest.getCurrentProfile().getId()){
              Log.d("ID's match: ", "attempting");
              if (userB.getEmail() == null){
                  Log.d("TODO", "Write code to show we need email");
                  Log.d("User B is : ", userB.getFirstName());
              }
          }
      }
  </code></pre>
  
  <p>Yet i get the following error:</p>
  
  <pre><code>05-19 09:33:37.034 6156-6156/com.ronone.securesender E/AndroidRuntime: FATAL EXCEPTION: main
      Process: com.ronone.securesender, PID: 6156
      java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ronone.securesender/com.ronone.securesender.HomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.ronone.securesender.amazonaws.models.nosql.SecureUsersDO.getUserId()' on a null object reference
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
          at android.app.ActivityThread.-wrap11(Unknown Source:0)
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
          at android.os.Handler.dispatchMessage(Handler.java:106)
          at android.os.Looper.loop(Looper.java:164)
          at android.app.ActivityThread.main(ActivityThread.java:6494)
          at java.lang.reflect.Method.invoke(Native Method)
          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
       Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.ronone.securesender.amazonaws.models.nosql.SecureUsersDO.getUserId()' on a null object reference
          at com.ronone.securesender.HomeActivity.checkUserEmail(HomeActivity.java:180)
          at com.ronone.securesender.HomeActivity.onCreate(HomeActivity.java:66)
          at android.app.Activity.performCreate(Activity.java:7009)
          at android.app.Activity.performCreate(Activity.java:7000)
          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
  </code></pre>
  
  <p>Thanks for any help in advance.</p>