JSP的param动作

一 语法 <jsp:param name="参数名" value="参数值"> 常常与<jsp:forward>一起使用，作为其子标签存在。   二 代码 1、login.jsp <%@ page language = "java" import = "java.util.*" contentType = "text/html; charset=utf-8" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+ "://" +request.getServerName()+ ":" +request.getServerPort()+path+ "/" ; %>   <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> < html >   < head >     < base href = " <%= basePath %> " >         < title > My JSP 'login.jsp' starting page </ title >              < meta http-equiv = "pragma" content = "no-cache" >          < meta http-equiv = "cache-control" content = "no-cache" >          < meta http-equiv = "expires" content = "0" >              < meta http-equiv = "keywords" content = "keyword1,keyword2,keyword3" >          < meta http-equiv = "description" content = "This is my page" >          <!--         <link rel =" stylesheet " type="text/ css " href ="styles.css">         -->     </ head >     < body >     < h1 > 系统登录 </ h1 >     < hr >     < form name = "loginForm" action = "dologin.jsp" method = "post" >       < table >         < tr >           < td > 用户名： </ td >           < td >< input type = "text" name = "username" /></ td >         </ tr >         < tr >           < td > 密码： </ td >           < td >< input type = "password" name = "password" /></ td >         </ tr >         < tr >           < td colspan = "2" >< input type = "submit" value = "登录" /></ td >         </ tr >       </ table >     </ form >   </ body > </ html > 2、dologin.jsp <%@ page language = "java" import = "java.util.*" contentType = "text/html; charset=utf-8" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+ "://" +request.getServerName()+ ":" +request.getServerPort()+path+ "/" ; %>   <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> < html >   < head >     < base href = " <%= basePath %> " >         < title > My JSP 'dologin.jsp' starting page </ title >              < meta http-equiv = "pragma" content = "no-cache" >          < meta http-equiv = "cache-control" content = "no-cache" >          < meta http-equiv = "expires" content = "0" >              < meta http-equiv = "keywords" content = "keyword1,keyword2,keyword3" >          < meta http-equiv = "description" content = "This is my page" >          <!--         <link rel =" stylesheet " type="text/ css " href ="styles.css">         -->     </ head >     < body >     < jsp:forward page = "user.jsp" >       < jsp:param value = " admin@123.net " name = "email" />       < jsp:param value = "888888" name = "password" />     </ jsp:forward >   </ body > </ html > 3、user.jsp <%@ page language = "java" import = "java.util.*" contentType = "text/html; charset=utf-8" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+ "://" +request.getServerName()+ ":" +request.getServerPort()+path+ "/" ; %>   <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> < html >   < head >     < base href = " <%= basePath %> " >         < title > My JSP 'user.jsp' starting page </ title >              < meta http-equiv = "pragma" content = "no-cache" >          < meta http-equiv = "cache-control" content = "no-cache" >          < meta http-equiv = "expires" content = "0" >              < meta http-equiv = "keywords" content = "keyword1,keyword2,keyword3" >          < meta http-equiv = "description" content = "This is my page" >          <!--         <link rel =" stylesheet " type="text/ css " href ="styles.css">         -->     </ head >     < body >     < h1 > 用户资料 </ h1 >     < hr >     <%        request.setCharacterEncoding( "utf-8" );        String username = "" ;        String password = "" ;        String email = "" ;        if (request.getParameter( "username" )!= null )        {           username = request.getParameter( "username" );        }        if (request.getParameter( "password" )!= null )        {           password = request.getParameter( "password" );        }        if (request.getParameter( "email" )!= null )        {           email = request.getParameter( "email" );        }            %>         用户名： <%= username %> < br >         密码： <%= password %> < br >         电子邮箱： <%= email %> < br >   </ body > </ html >   三 运行结果