public FormatException(String s,Throwable rootCause){
  super(s + ": " + rootCause.getLocalizedMessage());
  this.rootCause=rootCause;
}

public FormatException ( String s , Throwable rootCause ) { super ( s + ": " + rootCause . getLocalizedMessage ( ) ) ; this . rootCause = rootCause ; }
construct a formatexception with a detail message and root cause .
