AsyncTask: ClassCastException: java.lang.Object[] cannot be cast to java.lang.String[]

Question

In my application I run these code for gcm ccs(xmpp) and the code shows following error An error occurred while executing doinbackground.excute() This is the co

Answer 1

How is your sendTask declared? I suppose its simply AsyncTask sendTask;, if so then change it to:

AsyncTask<String, String, String> sendTask;

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The cause of this exception is similar to the one that occurs in below code:

Object arr1[] = new Object[] {null,null,null};
String arr2[] = (String[])arr1; // here java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String;

VarArgs in java are implemented as arrays, so when you declare sendTask as AsyncTask<String, String, String> then compiler will call your doInBackground with new String[]{null,null,null}, but when you declare it as AsyncTask then doInBackground is called with new Object[]{null,null,null}.

Because of type erasure, compiler will add hidden implicit cast from Object[] to String[]. This is to allow code as below to work correctly:

  AsyncTask sendTask = ...;
  Object[] arg = new String[]{null,null,null};
  sendTask.execute(arg);

Answer 2

Try

sendTask.execute(new String[]{""});

instead of

sendTask.execute(null, null, null);