JSP 标准标签库<x:choose>标签与Java switch语句有相同的功能。switch语句有case语句，而<x:choose>标签有<x:when>标签。switch语句有default语句，而<x:choose>标签有<x:otherwise>标签。
语法格式
<x:choose> <x:when select="<string>"> ... </x:when> <x:when select="<string>"> ... </x:when> ... ... <x:otherwise> ... </x:otherwise></x:choose>
属性
- <x:choose>没有属性。
- <x:when>的属性在下表中给出。
- <x:otherwise>没有属性。
<x:when>标签的属性：
| 属性 | 描述 | 是否必要 | 默认值 |
|---|---|---|---|
| select | 条件 | 是 | 无 |
实例演示
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%@ taglib prefix="x" uri="http://java.sun.com/jsp/jstl/xml" %><html><head> <title>JSTL x:choose 标签</title></head><body><h3>Books Info:</h3><c:set var="xmltext"> <books> <book> <name>Padam History</name> <author>ZARA</author> <price>100</price> </book> <book> <name>Great Mistry</name> <author>NUHA</author> <price>2000</price> </book> </books></c:set><x:parse xml="${xmltext}" var="output"/><x:choose> <x:when select="$output//book/author = 'ZARA'"> Book is written by ZARA </x:when> <x:when select="$output//book/author = 'NUHA'"> Book is written by NUHA </x:when> <x:otherwise> Unknown author. </x:otherwise></x:choose></body></html>运行结果如下：
BOOKS INFO:Book is written by ZARA