如何从Java中的列表数组获取格式化的字符串？

Question

Sorry, I'm beginner in Java. I work with Spring and Hibernate and I have problem. In Internet I can't find solution.

My Controller:

List<User> theModerators = userDAO.findAllModerators();

theModel.addAttribute("moderators", theModerators); return "moderators";

moderators.jsp:

<c:forEach items="${moderators}" var="m">
     <div>${m.firstName}</div>
     <c:forEach items="${m.companies}" var="company">
         <div>${company.compName}</div>
     </c:forEach>
</c:forEach>

I have problem with with company.compName. I want to get formated string with commas (ex: I got "MicrosoftApple", but I want - "Microsoft, Apple").

I know about join, for ex:

String allCompanies = String.join(", ", userCompanies);

But I can't add allCompanies string to theModerators, or create new array like theModerators but with allCompanies string.

I have worked with PHP/Laravel, and there I used joins into collections.

But in Java I can't do it.

Answer 1

The following should work

<c:forEach items="${moderators}" var="m">
     <div>${m.firstName}</div>
      <div>
     <c:forEach items="${m.companies}" var="company" varStatus="item">
         ${company.compName}
         <c:if test="${!item.last}">,</c:if>
     </c:forEach>
    </div>
</c:forEach>

I have made use of varStatus to avoid the last comma