jsp 2007-07-24 10:07:41 阅读155 评论0 字号：大中小 订阅
<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>
<%String str=request.getParameter("number"); //获得includeAction.jsp传来的值
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>
<form action="checklogin.jsp" method="get"> //由 checklogin.jsp处理表单数据
<table>
<tr>
<td>Username:</td>
<td><input type="text" name="username" value=<%=request.getParameter("user") %>></td> //获得参数"user"，初始值为null
</tr>
<tr>
<td>Password:</td>
<td><input type="password" name="password"></td>
</tr>
<tr colspan=2>
<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>
<%String name=request.getParameter("username"); //与login.jsp中name="username"对应
String password=request.getParameter("password"); //与login.jsp中name="password"对应
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>
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