JSP标签

Mahe666

掌握下面三个就可以，别的不常用

jsp:include

和指令的区别

代码层面：

include指令会把代码合二为一，最后是一个页面

在两个页面分别初始化同名变量就能看出来

include标签则是拼接代码，本质还是多个页面

代码示例

footer.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>
<head>
    <title>Title</title>
</head>
<body>

<h1>这是footer</h1>

</body>
</html>

header.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>
<head>
    <title>Title</title>
</head>
<body>

<h1>这是header</h1>

</body>
</html>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>
<head>
    <title>Title</title>
</head>
<body>

<jsp:include page="/common/header.jsp"/>

<h1>网页主体</h1>

<jsp:include page="/common/footer.jsp"/>

</body>
</html>

jsp:forward & jsp:param

jsp:forward 是请求转发

代码示例

jsptag.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>
<head>
    <title>Title</title>
</head>
<body>

<jsp:forward page="/testJsptag.jsp">
    <jsp:param name="username" value="admin"/>
    <jsp:param name="password" value="12345"/>
</jsp:forward>

<%--相当于 localhost:8080/testJsptag.jsp?username=admin&password=12345--%>

</body>

</html>

testJsptag.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>
<head>
    <title>Title</title>
</head>
<body>

username:<%=request.getParameter("username")%>

password:<%=request.getParameter("password")%>

</body>
</html>