Using foreach loop in JSF

foreach, java, jsf, jsp, web-services

Solution

If you are using JSF 2 you should change your page to xhtml, then you can use ui:repeat and get a lot more goodies from facelets.

I made two very simple pages, one as JSP and the other one as XHTML. They use a managed bean in request scope. Both are working and render three buttons in a row. Note that I use Glassfish as a server, since it was easier to getting started. For the Tomcat(7.x) you might need to copy the jsf-api, jsf-impl (2.x) and jstl (1.2) libs into the classpath.

This is the JSP page:

<%@page contentType="text/html" pageEncoding="UTF-8"%>

<%@taglib prefix="f" uri="http://java.sun.com/jsf/core"%>
<%@taglib prefix="h" uri="http://java.sun.com/jsf/html"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">

<f:view>
  <html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
        <title>JSP Page</title>
    </head>
    <body>
        <h:form>
          <c:forEach var="item" items="#{cart.items}">
            <h:commandButton value="#{item}"/>
          </c:forEach>
        </h:form>
    </body>
  </html>
</f:view>

Here the XHTML Page:

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
  xmlns:h="http://xmlns.jcp.org/jsf/html"
  xmlns:ui="http://java.sun.com/jsf/facelets">
  <h:head>
    <title>Simple JSF</title>
  </h:head>
  <h:body>
    <h:form>
        <ui:repeat value="#{cart.items}" var="item">
            <h:commandButton value="#{item}" />
        </ui:repeat>   
    </h:form>
  </h:body>
</html>

Why do you use a bean in request scope and set you variable there in the session? Keep it simple and change the bean to session scope:

@ManagedBean(name = "cart")
@SessionScoped
public class CartBean {

  private List<String> items;

  public CartBean() {
    items = new ArrayList<>();
    items.add("shirt");
    items.add("skirt");
    items.add("trouser");
  }

  public List<String> getItems() {
    return items;
  }

}

Problem

I need to create a list of commandbuttons on my page, but I have some trouble with it. I pass the list from my bean through request.setAttribute and it seems to work when I get the values one at a time, but when I run through a foreach loop, they all seem to be null (And thereby being generated, and having a default value 0, "" etc., as far as I know). Any help would be greatly appreciated! In the added code, I get the correct values when i make the buttons outside of the foreach loop, but not when I run the loop itself. The List is of integer type, and should later be a java object (ran into same problem). using JSF version 2.2. Both logtest() and gotoprofile() prints the interestpointer out. my bean has: ``` @ManagedBean(name="MyProfile") @RequestScoped ``` And I set my variable myInterestList in my bean with: ``` HttpSession session = (HttpSession) FacesContext.getCurrentInstance().getExternalContext().getSession(true); session.setAttribute("myInterestProfileName", profileName); <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> <%@taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql"%> <%@ page import="java.util.List,com.jsflogin.stringWithPointer" %> <%@taglib prefix="h" uri="http://java.sun.com/jsf/html"%> <%@ taglib prefix="f" uri="http://java.sun.com/jsf/core" %> <%@page contentType="text/html" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <f:view> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSF Successfull login</title> </head> <body> <h:form id="forloop"> <c:set var ="myTempList" value="${myInterestListYay}" scope="session"/> <c:out value="interest list"/><p> <h:commandButton value="#{myInterestListYay[1]}" action="#{MyProfile.logTest}"> <f:setPropertyActionListener target ="#{MyProfile.interestPointer}" value = "#{myInterestListYay[1]}"/> </h:commandButton><p> <ui:repeat var="orly"value="${myInterestListYay}" varstatus="status"> <c:out value="${status.index}"/><h:commandButton value="#{orly}" action="#{MyProfile.logTest}"> <f:setPropertyActionListener target ="#{MyProfile.interestPointer}" value = "#{orly}"/> </h:commandButton><p> </ui:repeat> <c:forEach var="orly" items="${MyProfile.interestsAndPointers}" varStatus="status" > <c:out value="${status.index}"/><c:out value=": "/><c:out value="${orly.stringName}"/><h:commandButton value="go to interest page" action="#{MyProfile.goToInterestProfile}"> <f:setPropertyActionListener target ="#{MyProfile.interestPointer}" value = "#{orly.pointer}"/> </h:commandButton><p> </c:forEach> </h:form> </body> </f:view> </html> ```

Original source