Using for loop inside of a JSP

Question

I want to loop through an ArrayList of  Festivals  and get their information with get methods  printing out all its values  For some reason when I use this code  it will always choose the  0 th value and not increment the loop   If I hard code the values as  get 1   it will get the correct values so my issue is clearly with the syntax    lt h1 gt All Festival Information lt  h1 gt       lt jsp useBean id  allFestivals  type  java util ArrayList  scope  session    gt       lt table border  1  gt           lt tr gt               lt td gt Festival Name  lt  td gt               lt td gt Location  lt  td gt               lt td gt Start Date  lt  td gt               lt td gt End Date  lt  td gt               lt td gt URL  lt  td gt           lt  tr gt           lt   for int i   0  i  lt  allFestivals size    i  1      gt               lt tr gt                         lt td gt   allFestivals get i  getFestivalName    lt  td gt                   lt td gt   allFestivals get i  getLocation    lt  td gt                   lt td gt   allFestivals get i  getStartDate    lt  td gt                   lt td gt   allFestivals get i  getEndDate    lt  td gt                   lt td gt   allFestivals get i  getURL    lt  td gt                 lt  tr gt           lt       gt       lt  table gt

User · Accepted Answer

You concrete problem is caused because you're mixing discouraged and old school scriptlets <% %> with its successor EL ${}. They do not share the same variable scope. The allFestivals is not available in scriptlet scope and the i is not available in EL scope.

You should install JSTL (<-- click the link for instructions) and declare it in top of JSP as follows:

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

and then iterate over the list as follows:

<c:forEach items="${allFestivals}" var="festival">
    <tr>      
        <td>${festival.festivalName}</td>
        <td>${festival.location}</td>
        <td>${festival.startDate}</td>
        <td>${festival.endDate}</td>
        <td>${festival.URL}</td>  
    </tr>
</c:forEach>

(beware of possible XSS attack holes, use <c:out> accordingly)

Don't forget to remove the <jsp:useBean> as it has no utter value here when you're using a servlet as model-and-view controller. It would only lead to confusion. See also our servlets wiki page. Further you would do yourself a favour to disable scriptlets by the following entry in web.xml so that you won't accidently use them:

<jsp-config>
    <jsp-property-group>
        <url-pattern>*.jsp</url-pattern>
        <scripting-invalid>true</scripting-invalid>
    </jsp-property-group>
</jsp-config>

User · Answer

Do this       lt   for int i   0  i  lt  allFestivals size    i  1      gt           lt tr gt                     lt td gt  lt   allFestivals get i  getFestivalName    gt  lt  td gt           lt  tr gt       lt       gt    Better way is to use c foreach see link jstl for each

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