Table 68 lists the JSTL functions

Table 68. Functions






Collection length



String manipulation

toUpperCase, toLowerCase substring, substringAfter, substringBefore trim replace indexOf, startsWith, endsWith, contains, containsIgnoreCase split, join escapeXml

Although the java.util.Collection interface defines a size method, it does not conform to the JavaBeans component design pattern for properties and so cannot be accessed via the JSP expression language. The length function can be applied to any collection supported by the c:forEach and returns the length of the collection. When applied to a String, it returns the number of characters in the string.

For example, the index.jsp page of the hello1 application introduced in Chapter 2 uses the fn:length function and the c:if tag to determine whether to include a response page:

   <%@ taglib uri=""      prefix="c" %>    <%@ taglib uri=""      prefix="fn" %>    <html>    <head><title>Hello</title></head>    ...    <input type="text" name="username" size="25">    <p></p>    <input type="submit" value="Submit">    <input type="reset" value="Reset">    </form>    <c:if test="${fn:length(param.username) > 0}" >      <%@include file="response.jsp" %>    </c:if>    </body>    </html>

The rest of the JSTL functions are concerned with string manipulation:

  • toUpperCase, toLowerCase: Changes the capitalization of a string

  • substring, substringBefore, substringAfter: Gets a subset of a string

  • TRim: TRims whitespace from a string

  • replace: Replaces characters in a string

  • indexOf, startsWith, endsWith, contains, containsIgnoreCase: Checks whether a string contains another string

  • split: Splits a string into an array

  • join: Joins a collection into a string

  • escapeXml: Escapes XML characters in a string

The JavaT EE 5 Tutorial
The JavaT EE 5 Tutorial
Year: 2004
Pages: 309 © 2008-2017.
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