(define-syntax jlambda
  (syntax-rules (boolean)
    ((jlambda class boolean name argtype ...)
     (lambda (object . args)
       (let ((m (method class name boolean argtype ...)))
	 (call-boolean-method object m (jvalues 
					(zip (list argtype ...) args))))))
    ((jlambda class return-type name argtype ...)
     (lambda (object . args)
       (let ((m (method class return-type name argtype ...)))
	 (call-object-method object m (jvalues 
				       (zip (list argtype ...) args))))))))

(ppexpand* '(jlambda java.lang.String boolean contains java.lang.CharSequence))