list to csv

javascript裡有join()

var ooo = ['a','b','c'];
var csv = ooo.join();   // output: a,b,c

java裡可以用
org.apache.commons.lang.StringUtils

String[] stringArray = {"a","b","c"};
List<string> stringList = Arrays.asList(stringArray);

StringUtils.join( stringArray, "," );  // output:a,b,c
StringUtils.join( stringList, "," );  // output:a,b,c