Android : Java Null Pointer Exception in Android while Instantiating an IntentService from an Activity

I am creating an application which has an activity and an intent service which will be called from this activity. The purpose of the Intent service is to send a file from the android device to a remote server. The file is created by the application.

The problem is : I am getting a Null pointer exception when I try to instantiate the intent service from a method(which i created) in the activity.

This is the error Eclipse is showing :

The Console Output from the Eclipse is :

[2014-08-07 10:40:02 - ddms] null
java.nio.BufferOverflowException
    at java.nio.HeapByteBuffer.put(HeapByteBuffer.java:200)
    at com.android.ddmlib.JdwpPacket.movePacket(JdwpPacket.java:235)
    at com.android.ddmlib.Debugger.sendAndConsume(Debugger.java:347)
    at com.android.ddmlib.Client.forwardPacketToDebugger(Client.java:665)
    at com.android.ddmlib.MonitorThread.processClientActivity(MonitorThread.java:344)
    at com.android.ddmlib.MonitorThread.run(MonitorThread.java:263)

And the Code that calls starts the intent service is :

Intent iservice = new Intent(Viewer1.this, DataUploader.class);
startService(iservice);

Viewer1 is the Activity from which I want to call the service. DataUploader is the Intent service I am trying to start.

Can anyone help me in debugging the error. I am sure that there is no error in any other part of the activity.

Note : I am calling the startService() method from a method which I created.