El and Jstl Learning (ii)--JSTL technology

1. JSTL Overview

JSTL (JSP standard tag Library), JSP standards tag libraries, can be embedded in the JSP page using the form of tags to complete business logic and other functions.

The purpose of the JSTL is to replace the script code in the JSP page, as is the case with El.

The JSTL standard Tag Library has 5 sub-libraries, but as it develops, its core library is often used today

Tag Library	The URI of the tag library	Prefix
Core	Http://java.sun.com/jsp/jstl/core	C
i18n	Http://java.sun.com/jsp/jstl/fmt	Fmt
Sql	Http://java.sun.com/jsp/jstl/sql	Sql
Xml	Http://java.sun.com/jsp/jstl/xml	X
Functions	Http://java.sun.com/jsp/jstl/functions	Fn

2. Jstl Download and Import

Jstl Download:

Download the Jstl jar package from the Apache website. Go to the "http://archive.apache.org/dist/jakarta/taglibs/standard/binaries/" url to download the JSTL installation package, Jakarta-taglibs-standard-1.1.2.zip.

Then unzip the downloaded JSTL installation package, and at this point, you can see two jar files in the Lib directory, respectively, Jstl.jar and Standard.jar.

Where the Jstl.jar file contains the interfaces and related classes defined in the JSTL specification, the Standard.jar file contains the. class file used to implement JSTL and 5 tag Library descriptor files (TLDs) in Jstl

Import two jar packages into the lib of our project

Import the core tag library using JSP taglib directives

3. Common tags for jstl core libraries

1) <c:if test= "" > Label

Where test is the condition that returns a Boolean

2) <c:forEach> label

There are two combinations of modes of use:

El and Jstl Learning (ii)--JSTL technology