JSP script elements and instruction elements and action directives and built-in objects

Three scripting elements:

<%! int i=0> 声明变量
　<%=a+b%> 表达式
　<%
　　if(){

　　}else{

　　}

%> Script Segment

Three directive elements:

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
　<%@ include file="..."%>
　<%@ taglib uri=http://www.jspcentral.com/tags prefix="public"%>

8 Action Instructions:

Page Jump:

<jsp:forward page="">
　　　<jsp:param name="username" value="<%=username%>"/>
　　　<jsp:param name="password" value="<%=password%>"/>
　　</jsp:forward>
Page contains:

<jsp:include page="" flush="true">
　　<jsp:include page="" flush="true">
　　　<jsp:param name="username" vlaue="jsmith">
　　</jsp:include>

To create a bean:

<jsp:useBean id="" scope="session" class="session.Carts"/>
　　<jsp:getProperty name="cart" property="*"/>
　　<jsp:useBean id="checking" scope="" class="">
　　　　 <jsp:setProperty name="checking" property="balance" value="0.0">
　　</jsp:useBean>