question: private static void parseExpression ( final Reader reader , final boolean writingString , final StringBuilder templateExpressions ) throws IOException { if ( ! writingString ) { templateExpressions . append ( "out << \"\"\"" ) ; } templateExpressions . append ( "${" ) ; while ( true ) { int c = reader . read ( ) ; if ( c == - 1 ) break ; if ( c == '%' ) { c = reader . read ( ) ; if ( c == '>' ) break ; templateExpressions . append ( '%' ) ; } templateExpressions . append ( ( char ) c ) ; } templateExpressions . append ( '}' ) ; }
target:  Parse a &lt;%= .... %&gt; expression