private void validate ( ) throws IOException { if ( null != _error ) { throw _error ; } if ( ! _isReadLine && ! _isReady ) { //If there is no data available then isReady will have returned false and this throw an IllegalStateException if ( TraceComponent . isAnyTracingEnabled ( ) && tc . isErrorEnabled ( ) ) Tr . error ( tc , "read.failed.isReady.false" ) ; throw new IllegalStateException ( Tr . formatMessage ( tc , "read.failed.isReady.false" ) ) ; } }
This checks if we have already had an exception thrown . If so it just rethrows that exception This check is done before any reads are done