In this tutorial you will learn about the JSTL functions fn:substring.
JSTL fn substring Example
In this tutorial you will learn about the JSTL functions fn:substring.
fn:substring() function of JSTL functions library is used to find out the subset of the String.
Syntax :
String substring(String, int, int)
First argument of this function is a string form which you want to find out the subset of string, second and third arguments are index position of the string that specifies the range of substring.
Example :
Here an example is being given below will demonstrate you how to find out the substring from a string. In this example I have created a JSP page where I have designed a form to take the string as an input from the user and the index values of a substring that you want to find out.
JstlFnSubstring.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>JSTL fn:substring Example</title>
</head>
<body>
<form>
<p>Enter String :
<input type="text" name="str"/></p>
<p>Enter first index :
<input type="text" name="firstIndex"/></p>
<p>Enter last index :
<input type="text" name="lastIndex"/></p>
<input type="submit" value="Find Substring"/>
</form>
<%
if(request.getParameter("str") != null)
{
%>
<P>Resulting Substring :
<b>${fn:substring(param.str, param.firstIndex, param.lastIndex)}</b></P>
<%
}
%>
</body>
</html>
How to run this example
Here I am using an IDE Eclipse so I am giving the process of executing this example in perspective of Eclipse. Before executing this example you will have needed to add the following jar files :
- jstl.jar
- standard.jar
After adding of these jar files you may execute your program in the following ways :
- Select JstlFnSubstring.jsp file of your project in Project Explorer -> RightClick -> Run As -> Run On Server -> Choose your server -> Finish.
- On the Eclipse Editor go to your JstlFnSubstring.jsp -> RightClick -> Run As -> Run On Server -> Choose your server -> Finish.
- Go to Run button look at the toolbar in green color and click -> Choose your server -> Finish.
- A simplest way to execute the example in Eclipse is to use the CTRL+F11 key -> Run On Server -> Choose your server -> Finish
NOTE : In all of the above execution processes you may start the server first and stop the server each time after the execution if not, each time you will may prompted to a dialog box to Restart the server in Eclipse.
Output :
1. When you will execute the above JSP page you will get the output on your eclipse browser as follows :
2. When you will click on submit button an output will be displayed as follows :
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