jsp:param标签使用

Jsp 中 param 标签的使用

@Author:ZJ 07-2-21

Blog: http://zhangjunhd.blog.51cto.com/

<jsp:param> 操作被用来以“名 - 值”对的形式为其他标签提供附加信息。它和 <jsp:include> 、 <jsp:forward> 、 <jsp:plugin> 一起使用，方法如下：

<jsp:param name=”paramName” value=”paramValue”/>

其中， name 为与属性相关联的关键词， value 为属性的值。

1 ． <jsp:param> 与 <jsp:include> 配合使用

includeAction.jsp

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > Include </ title > </ head > < body >     <% double i = Math.random(); %>     < jsp:include page = "come.jsp" > // 加载 come.jsp     < jsp:param name = "number" value = "<%=i%>" /> // 传递参数 </ jsp:include > </ body > </ html >

 

come.jsp

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > come </ title > </ head > < body bgcolor = cyan >   < Font Size = 3 >   <% // 获得 includeAction.jsp 传来的值 :     String str = request.getParameter( "number" ); double n = Double.parseDouble(str); %>     The value form includeAction is: < br > <%= n %> </ Font > </ body > </ html >

2 ． <jsp:param> 与 <jsp:forward> 配合使用

用户登录示例

login.jsp

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > Login </ title > </ head > < body >      // 由 checklogin.jsp 处理表单数据    < form action = "checklogin.jsp" method = "get" >         < table >             < tr >               < td > Username: </ td >               < td > // 获得参数 "user" ，初始值为 null                   < input type = "text" name = "username"                      value = <%= request.getParameter( "user" ) %> >               </ td >            </ tr >            < tr >               < td > Password: </ td >               < td >                   < input type = "password" name = "password" >               </ td >            </ tr >            < tr >               < td >                   < input type = "submit" value = "login" >               </ td >            </ tr >        </ table >     </ form > </ body > </ html >

 

checklogin.jsp

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > CheckLogin </ title > </ head > < body >     <%       // 与 login.jsp 中 name="username" 对应        String name = request.getParameter( "username" );        // 与 login.jsp 中 name="password" 对应 String password = request.getParameter( "password" );        if (name.equals( "admin" ) && password.equals( "admin" )) {     %>     < jsp:forward page = "success.jsp" > // 跳转至 success.jsp        < jsp:param name = "user" value = "<%=name%>" /> // 携带参数 "user"     </ jsp:forward >     <%     } else {     %>     < jsp:forward page = "login.jsp" > // 跳转至 login.jsp        < jsp:param name = "user" value = "<%=name%>" /> // 携带参数 "user"     </ jsp:forward >     <%     }     %> </ body > </ html >

success.jsp

< html > < head >     < meta http-equiv = "Content-Type" content = "text/html; charset=GB18030" >     < title > Success </ title > </ head > < body >     Welcome, <%= request.getParameter( "user" ) %> // 获得参数 "user" </ body > </ html >