Custom Jstl function Label

1. Write a tool class
   

   public class Utilfunction {
   
   Public Utilfunction () {
   
   }
   
   /**
   * @param start 0,start intercept
   * @param end end, intercept
   * @param info
   * @param t fill
   * @return
   */
   public static String subString (int start,int end,string info,string t) {
   String infostart=info.substring (0,start);
   String infoend=info.substring (end);
   return infostart+t+infoend;
   }
   
   Test
   public static void Main (string[] args) {
   Mobile phone number before 3 4
   System.out.println (Utilfunction.substring (3, 7, "15216888619", "* * * *"));
   }
   }

2. Define a. tld file below the Web-inf

<?xml version= "1.0" encoding= "UTF-8"?>

<taglib xmlns= "HTTP://JAVA.SUN.COM/XML/NS/J2EE"
Xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"
xsi:schemalocation= "Http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
version= "2.0" >

<tlib-version>1.0</tlib-version>
<short-name>my</short-name>
<uri>http://www.xx.com</uri>

<!--jstl Custom function Get province--
<function>
<name>subString</name>
<function-class>util. Utilfunction</function-class>
<function-signature>java.util.string subString (int, int,java.lang.string,java.lang.string) </ Function-signature>
</function>
</taglib>

3.web.xml definition

<jsp-config>
<taglib>
<taglib-uri>http://www.xx.com</taglib-uri>
<taglib-location>/WEB-INF/tld/utilFunction.tld</taglib-location>
</taglib>
</jsp-config>

4.jsp page reference

<%@ taglib uri= "http://java.sun.com/jsp/jstl/functions" prefix= "FN"%>
<%@ taglib prefix= "YH" uri= "http://www.xx.com"%>

${xx:substring (3, 7, Userinfo.smobile, "* * *")}

Note:

UserInfo for Request.setbean ()

Request binding is ${userinfo.smobile} if the FN function uses remove ${}, direct userinfo.smobile

Custom Jstl function Label