jstl function join
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<hr width="500" color="red" align="left">
<c:set var="str" value="JSTL(JSP Standard Tag Library)"/>
<c:set var="array" value="${fn:split(str,' ')}"/>
join : <b>${fn:join(array,"-")}</b>
<hr width="500" color="red" align="left">
<hr width="500" color="red" align="left">
</body>
</html>
JSTL tag ex) : https://ahnsk39.blogspot.com/2017/08/jstljsp-standard-tag-library.html
