regex - Java Regular expression with variable string -

i want find occurrences of words in listarray comparing string. far, able loop, store possible combinations , run them using matches i.e.

        for(string temp_keywords: keywords){         final_keywords_list.add(" "+ temp_keywords+ " ");         final_keywords_list.add(" "+ temp_keywords+".");         final_keywords_list.add(" "+ temp_keywords+ ",");         final_keywords_list.add(" "+ temp_keywords+ "!");         final_keywords_list.add(" "+ temp_keywords+ "/");         final_keywords_list.add(" "+ temp_keywords+ "?");     }     (string temp_keywords : final_keywords_list) {             string add_space = temp_keywords.tolowercase();             p = pattern.compile(add_space);             m = p.matcher(handler_string);             int count = 0;             while (m.find()) {                 count += 1;             } 

however, want remove manual addition combinations , regex. i've seen examples of words regex how add variable string regex? sorry, beginner java learner.

is need?

string inputstring = .... string[] keywords = ....  stringbuilder sb = new stringbuilder(); for(string keyword: keywords)   sb.append("(?<= )").append(keyword).append("(?=[ .,!/?])").append("|"); sb.setlength(sb.length() - 1); //removes trailing "|". assumes keywords.size() > 0.  pattern p = pattern.compile(sb.tostring()); matcher m = p.matcher(inputstring); int count = 0; while (m.find())   count++; 

it creates single regex, compiles it, , counts matches.