Iterate over elements of List and Map using JSTL tag

by

Mark, this is already answered in your previous topic. But OK, here it is again:

Suppose ${list} points to a List<Object>, then the following

<c:forEach items="${list}" var="item">
    ${item}<br>
</c:forEach>

does basically the same as as following in “normal Java”:

for (Object item : list) {
    System.out.println(item);
}

If you have a List<Map<K, V>> instead, then the following

<c:forEach items="${list}" var="map">
    <c:forEach items="${map}" var="entry">
        ${entry.key}<br>
        ${entry.value}<br>
    </c:forEach>
</c:forEach>

does basically the same as as following in “normal Java”:

for (Map<K, V> map : list) {
    for (Entry<K, V> entry : map.entrySet()) {
        System.out.println(entry.getKey());
        System.out.println(entry.getValue());
    }
}

The key and value are here not special methods or so. They are actually getter methods of Map.Entry object (click at the blue Map.Entry link to see the API doc). In EL (Expression Language) you can use the . dot operator to access getter methods using “property name” (the getter method name without the get prefix), all just according the Javabean specification.

That said, you really need to cleanup the “answers” in your previous topic as they adds noise to the question. Also read the comments I posted in your “answers”.

More Related Contents:

  1. javax.servlet.ServletException: javax.servlet.jsp.JspTagException: Don’t know how to iterate over supplied “items” in
  2. Calculate total sum of all numbers in c:forEach loop
  3. c:forEach throws javax.el.PropertyNotFoundException: Property ‘foo’ not found on type java.lang.String
  4. How to get a index value from foreach loop in jstl
  5. Sort a list of objects in Flutter (Dart) by property value
  6. Concatenating two lists – difference between ‘+=’ and extend()
  7. What’s the most Pythonic way to identify consecutive duplicates in a list?
  8. How to access objects in EL expression language ${}
  9. Convert a matrix to a list of column-vectors
  10. Search for an item in a Lua list
  11. List as form backing object using Spring 3 MVC, correct syntax?
  12. java.lang.NoClassDefFoundError: javax/servlet/jsp/tagext/TagLibraryValidator
  13. Java 8: sort list of objects by attribute without custom comparator
  14. Lazy lists in Prolog?
  15. I can pass a variable from a JSP scriptlet to JSTL but not from JSTL to a JSP scriptlet without an error
  16. How to clone or copy a list in kotlin
  17. How to count number of element occurrences in a list in Prolog
  18. Intersection and union of 2 lists
  19. How to recursively reverse a list using only basic operations?
  20. Difference between a Seq and a List in Scala
  21. XPath 1.0 to find if an element’s value is in a list of values
  22. How can I read the contents of a file into a list in Lisp?
  23. Iterating through a List Object in JSP
  24. R: Print list to a text file
  25. Add or remove an entry from a List type attribute in a DynamoDB table item
  26. Make ${} operator XSS safe in Struts 2 (same as tapestry)
  27. Unicode characters in servlet application are shown as question marks
  28. How does one enable selections in SwiftUI’s List
  29. Splitting a list of items into two lists of odd and even indexed items
  30. Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core”

Leave a Comment