CODEWITHSUNDEEP
javaspringjspspring-mvc
Tobias Kuess
Tobias Kuess

Reputation: 749

JSP: Iterate over List and get each item (ForEach)

I am having a hard time iterating over a List with jsp. I did this several times with velocity, but I somehow can't get it to work with jsp.

This is an easy example I am trying to get to work:

       @RequestMapping("/bye")
    public ModelAndView byeWorld() {
        String message = "Goodbye World, Spring 4.1.2!";

        List<Map<String, Object>> data = dataProvider.getVorgaengeGesamtByArkNr();

        model.put("table", data);
        model.put("columnNames", utils.getColumnNames(data));
        return new ModelAndView("test", model);
    }

utils.getColoumnNames returns an List.

This is the lopp in the .jsp:

    <c:forEach var="entry" items="${columnNames}">
        <tr>
            entry
        </tr>
    </c:forEach>

Response looks like this:

    <c:forEach var="entry" items="[ARKNR_ABTEILUNG, LIEFERANT_ID, LIEFERANT_NAME, RECHNUNGS_NR, RECHNUNGS_DATUM, RECHNUNGS_EINGANG, STATUS_ID, STATUS_NAME_DE, RECHNUNGS_BETRAG_BRUTTO, RECHNUNGS_BETRAG_WAEHRUNG, SKONTO, WEITERBERECHNUNG, ARCHIV_ID, PROZESS_ID, AKTUELLER_BENUTZER, AKTUELLER_BENUTZER_ID, RECHNUNG_ID, KV_ID, ARKNR, DEPARTMENT_ID, FIBU_NAME, DBRD_ID]">
    <tr>
        entry
    </tr>
    </c:forEach>

So the list is just replacing ${columnNames}, not looping through it at all.

    @SuppressWarnings("unchecked")
public static List<String> getColumnNames(List list) {
    if (list.size() > 0) {
        Map map = (Map)list.get(0);
        List<String> columnNames = new ArrayList<String>();

        for (Object entry : map.keySet())
        {
            logger.debugT(entry.toString());
            columnNames.add(entry.toString());
        }

        return columnNames;
    } else {
        return null;
    }
}

Upvotes: 1

Views: 7747

Answers (2)

ooozguuur
ooozguuur

Reputation: 3466

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<body>
    <h2>Example</h2>

    <c:if test="${not empty columnNames}">
         <h2>Columns</h2>
        <ul>
            <c:forEach var="col" items="${columnNames}">
                <li>${col}</li>
            </c:forEach>
        </ul>

    </c:if>
</body>
</html>

Upvotes: 1

user2575725
user2575725

Reputation:

You need to use ${}, also use td to make it visible within table.

<tr>
   <td>${entry}</td>
</tr>

Edited:

As Jackk already pointed out, you need to import that taglib in order to use forEach on the top of the jsp.

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

Upvotes: 0

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