question: public static Result verify ( String sid , String code ) { String id = "//captcha/" + sid ; Code c = ( Code ) Cache . get ( id ) ; if ( c == null ) { log . warn ( "no code in cache, sid=" + sid ) ; return Result . badcode ; } else if ( ! X . isSame ( code , c . code ) ) { log . warn ( "is not same, code.server=" + c . code + ", code.client=" + code ) ; return Result . badcode ; } else if ( c . expired < System . currentTimeMillis ( ) ) { log . warn ( "expired, expired=" + c . expired ) ; return Result . expired ; } return Result . ok ; }
target:  verify the code associated