question: public String replaceSomeTokens ( String queryString , Map < String , String > replacements ) { Matcher matcher = tokenPattern . matcher ( queryString ) ; StringBuffer buf = new StringBuffer ( ) ; while ( matcher . find ( ) ) { String origToken = matcher . group ( 1 ) ; if ( origToken != null ) { String replacement = replacements . get ( origToken ) ; if ( replacement == null ) { replacement = "${" + origToken + "}" ; } matcher . appendReplacement ( buf , "" ) ; buf . append ( replacement ) ; } } matcher . appendTail ( buf ) ; return buf . toString ( ) ; }
target:  Replaces some tokens in a query string with tokens of format ${token-name}   with the given replacements, which may again be tokens (e.g. in another format) or values. Tokens that have no replacement defined stay in the original token format.