Jstl Association of different versions and El expressions

JSTL currently has 3 versions: JSTL1.0, JSTL1.1, JSTL1.2

JSTL1.0 and JSTL1.1 contain 2 jar packages of Jstl.jar and Standard.jar , which are required to refer to these 2 jar packages separately in the j2ee4 version.

JSTL1.2 in the J2ee5 jar is Jstl-1.2.jar, in J2ee6 is Jstl-imp.jar.

Variations for each version:

The servlet and JSP specifications supported by JSTL1.0 (EL), JSTL 1.1, and JSTL 1.2 are also different:

In Web. XML, declare the corresponding servlet version:

 jstl1.2 needs servlet2.5  <  web-app  xmlns    version  =" 2.5 " Span style= "color: #ff0000;" > 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-app_2_5.xsd " >  

 jstl1.1 and JSP2.0 need servlet2.4  <  Span style= "color: #800000;" >web-app  xmlns    xmlns:xsi  ="/http Www.w3.org/2001/XMLSchema-instance "  version  = "2.4"   Xsi:schemalocation  = "Http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4. xsd " >  

JSTL1.0 and JSP1.2 need servlet2.3 <  xmlns= "Http://java.sun.com/xml/ns/j2ee"  xmlns:xsi= "http://www.w3.org/ 2001/xmlschema-instance "  version=" 2.3 "  xsi:schemalocation="/http/ JAVA.SUN.COM/XML/NS/J2EE   http://java.sun.com/xml/ns/j2ee/web-app_2_3. xsd ">

How to refer to Taglib in JSP:

JSTL1.0 is used in the following ways:<%@ taglibURI= "Http://java.sun.com/jstl/core"prefix= "C" %>JSTL1.1 is used in the following ways:<%@ taglibURI= "Http://java.sun.com/jsp/jstl/core"prefix= "C" %>The JSTL1.2 method is used for<%@ taglibURI= "Http://java.sun.com/jsp/jstl/core"prefix= "C" %>

Support for El Expressions:

Support for El expressions supported by default is:

1, servlet2.4

2, J2ee6

El expressions are not supported by default and require one of the following 2 configurations to turn on EL:

1, add in the JSP:

<% @ Page iselignored = " false " %>

2. Add in WEB.XM:

<Jsp-config>         <Jsp-property-group>             <Url-pattern>*.jsp</Url-pattern>             <el-ignored>False</el-ignored>         </Jsp-property-group>     </Jsp-config>

The final conclusion: if the new project recommends the use of J2ee6, because the new project cannot also use servlet2.4.