JSTL-java ee5 tutorial

JSTL includes a wide variety of tags that fit into discrete functional areas. To reflect this, as well as to give each area its own namespace, JSTL is exposed as multiple tag libraries. The URIs for the libraries are as follows:

Core: http://java.sun.com/jsp/jstl/core
XML: http://java.sun.com/jsp/jstl/xml
Internationalization: http://java.sun.com/jsp/jstl/fmt
SQL: http://java.sun.com/jsp/jstl/sql
Functions: http://java.sun.com/jsp/jstl/functions

the following table summarizes these functional areas along with the prefixes.

JSTL Tags 

Area

Subfunction

Prefix

Core

Variable support

c

Flow control

URL management

Miscellaneous

XML

Core

x

Flow control

Transformation

I18n

Locale

fmt

Message formatting

Number and date formatting

Database

SQL

sql

Functions

Collection length

fn

String manipulation

Thus, the tutorial references the JSTL core tags in JSP pages by using the following taglib directive:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" 
    prefix="c" %>  

In addition to declaring the tag libraries, tutorial examples access the JSTL API and implementation. In the Application Server, the JSTL TLDs and libraries are distributed in the archive <J2EE_HOME>/lib/appserv-jstl.jar. This library is automatically loaded into the classpath of all web applications running on the Application Server, so you don't need to add it to your web application.

 

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sql查询语句可以写为：

<sql:query var="books" sql="select * from web_bookstore_books where bookId='203'"></sql:query>

带参数：

<sql:query var="books" dataSource="jdbc/BookDB">
        select * from web_bookstore_books where bookId=? <sql:param value="${bid}"/>
</sql:query>

还有：

<sql:query var="books" sql="select * from web_bookstore_books where bookId = ?" >
       <sql:param value="${bookId}" />
</sql:query>

数据库更新：

<sql:update var="books" sql="update web_bookstore_books set inventory = inventory - ? where bookId = ?" >
       <sql:param value="${item.quantity}" />
       <sql:param value="${bookId}" />
</sql:update>

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注意配置文件：

<resource-ref>
        <res-ref-name>jdbc/BookDB</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
        <res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>