Exception processing async thread queue Exception processing async thread queue java.lang.UnsupportedOperationException

Exception processing async thread queue Exception processing async thread
queue java.lang.UnsupportedOperationException

String contents = intent.getStringExtra("SCAN_RESULT");
String format = intent.getStringExtra("SCAN_RESULT_FORMAT");
String[] contentsArray=contents.split("\\.");
for(int i=0;i<=contentsArray.length;i++){
String str=contentsArray[i];
Log.e("FFFFFFF", str);
}
While splitting the string content i got the error below.
Exception processing async thread queue Exception processing async thread
queue java.lang.UnsupportedOperationException
What may be the reason..plz help