Invoking Java static methods in El

You recently encountered a problem in your project that calls for static methods, such as:

<items=var=<p> total: ${com.example.tools.gettotal (bean.nums)}</p> </c:foreach>       

However, the above code can not be compiled, can only seek other methods. After reviewing various documents, we found 3 kinds of solutions.

1, create a Get method directly for the bean

Double Gettotal () {       return com.example.Tools.getTotal (nums);}

Then use it directly in El:

Total:${bean.total}

2, create the tools#gettotal as an El function. First create a /WEB-INF/my.tld file:

<?XML version= "1.0" encoding= "UTF-8"?><Taglib xmlns="Http://java.sun.com/xml/ns/javaee" Xmlns:xsi="Http://www.w3.org/2001/XMLSchema-instance" xsi:schemalocation="Http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-jsptaglibrary_2_1.xsd" version="2.1" > <Display-name>custom Functions</Display-name> <tlib-version>1.0</Tlib-version><Short-name>my</Short-name><!--short-name elements don't write-- <Uri>http://example.com/functions</Uri> <Function>  <name>calculatetotal</name>  <function-class>com.example.tools</< Span class= "title" >function-class>  < function-signature>double gettotal (double[]) </< span class= "tag" >function-signature> </function></ Taglib>               

Then define the mappings for URI and TLD file paths in Web. xml:

<jsp-config>        <<taglib-uri>http://example.com/functions</  <taglib-location>/web-inf/my.tld</</</jsp-config>   

The taglib is then introduced into the JSP header to be used:

<%@ taglib uri="http://example.com/functions" prefix="%>     

Where the URI corresponds to the Taglib-uri in Web. Xml. Finally, the function can be used in El:

<items=var=<p> total: ${my:calculatetotal (bean.nums)}</p>  </c:foreach>       

3, use spring's spel:

JSP Header Introduction:

<%@taglib prefix="S" uri="%>     

Use:

<items=var=<expression=var=<p> total: ${total}</p ></c:foreach>          

Invoking Java static methods in El