<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<c:choose>
<c:when test="${param.portchoice == 'news'}">
<head><title>News Portal</title></head>
<body>
<h1>Welcome to the News Portal!</h1>
</body>
</c:when>
<c:when test="${param.portchoice == 'weather'}">
<head><title>Weather Portal</title></head>
<body>
<h1>You Get the Latest Weather!</h1>
</body>
</c:when>
<c:when test="${param.portchoice == 'entertainment'}">
<head><title>Entertainment Portal</title></head>
<body>
<h1>Entertainment News Just for You!</h1>
</body>
</c:when>
<c:otherwise>
<head><title>System Portal</title></head>
<body>
<h1>Application logic problem detected!</h1>
</body>
</c:otherwise>
</c:choose>
</html>上面的代码使用了标志库，请问uri="http://java.sun.com/jsp/jstl/core"是什么意思，是不是可以随便乱写的，还是有什么规定的？
<html>
<c:choose>
<c:when test="${param.portchoice == 'news'}">
<head><title>News Portal</title></head>
<body>
<h1>Welcome to the News Portal!</h1>
</body>
</c:when>
<c:when test="${param.portchoice == 'weather'}">
<head><title>Weather Portal</title></head>
<body>
<h1>You Get the Latest Weather!</h1>
</body>
</c:when>
<c:when test="${param.portchoice == 'entertainment'}">
<head><title>Entertainment Portal</title></head>
<body>
<h1>Entertainment News Just for You!</h1>
</body>
</c:when>
<c:otherwise>
<head><title>System Portal</title></head>
<body>
<h1>Application logic problem detected!</h1>
</body>
</c:otherwise>
</c:choose>
</html>上面的代码使用了标志库，请问uri="http://java.sun.com/jsp/jstl/core"是什么意思，是不是可以随便乱写的，还是有什么规定的？
这个是表示加载ＪＳＰ ２．０的标准标签库中的核心标签库，里面的prefix值可以改，但是不推荐，后面uri里的写法是固定的．
标准标签库中还有其他的标签
<%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %>
导入标准标签库的ＳＱＬ标签库.
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
国际标准化库
．．．．．．．．．