[color=red]JSP动作元素：[/color]
<%@page contentType="text/html;charset=UTF-8"%><%request.setCharacterEncoding("GB2312");%><jsp:useBean id="student" class="ch04.Student" scope="session"/><jsp:setProperty name="student" property="*"/><jsp:setProperty name="student" property="age" value="30"/><html><head><title>Action动作示例</title><meta http-equiv="Content-Type" content="text/html;charset=UTF-8"></head><body><%if(student.isQuery()){ %><h2>查询结果:</h2><br> 姓名：<jsp:getProperty name="student" property="name"/><br> 学号：<jsp:getProperty name="student" property="stuId"/><br> 年龄：<jsp:getProperty name="student" property="age"/><br><%} %><hr><h2>学生</h2><form name="javabean" action="action.jsp" method="get"><input type=hidden name="query" value="true"><p>姓名<input type="text" name="name"><p>学号<input type="text" name="stuId"><p><input type="submit" value="提交"/><input type="reset" value="重置"/></p></form></body></html>
JSP内置对象：
response对象:
<%@page contentType="text/html;charset=UTF-8"%><% String str=request.getParameter("submit"); if(str==null){ str=""; } if(str.equals("yes")){ response.setContentType("application/msword;charset=UTF-8"); }%><html><head> <title>response对象示例</title></head><body> <p>我正在学习response对象 <p>将当前页面保存为word文档吗？ <form method="get" name="form"> <input type="submit" value="yes" name="submit"> </form></body> </html>
out对象：
getBufferSize()方法取得目前缓冲区的大小(KB),getRemaining()取得目前使用后还剩余的缓冲区的大小(KB);
<%@page contentType="text/html;charset=UTF-8"%><html> <head> <title>OUT示例</title> </head><body> <h2>javax.servlet.jsp.JspWriter-out对象</h2> <% out.println("学习使用out对象:<br>"); int Buffer=out.getBufferSize(); int Available=out.getRemaining(); %> BufferSize:<%=Buffer%><br> Available:<%=Available%><br></body></html>
session对象：
<%@page contentType="text/html;charset=UTF-8"%><%! int number=0; synchronized void countPeople(){ number++; }%><% if(session.isNew()){ countPeople(); String str=String.valueOf(number); session.setAttribute("count",str); } String sessionID=session.getId();%><html><head> <title>session对象示例</title></head><body><h2>session</h2><p>您的session对象的ID是：<%=sessionID%><p>您是第<%=(String)session.getAttribute("count")%>个访问本站的人</body></html>
application对象：
<%@page contentType="text/html;charset=UTF-8"%><% int Num=0; String activePage=application.getRealPath("header.jsp");%><html> <head> <title>application对象示例</title> </head> <body> <center> <font size=5>applicaion对象示例</font> </center> <hr> 本页面对应的实际路径是:<%=activePage%><br> <br> application对象中变量Num的值是：<%=Num%> </body></html>
exception对象：
error.jsp页面在运行中会抛出空指针导常，如：
<%@page contentType="text/html;charset=UTF-8"%><%@page import="java.util.*" errorPage="header.jsp"%><% Calendar rightNow=null; rightNow.getTime();%>
如果发生空指针异常，重定向到exception.jsp中，它使用exception对象报告发生异常的错误原因：
<%@page contentType="text/html;charset=UTF-8" isErrorPage="true"%><%@page import="java.io.*"%><html> <head> <title>exception对象示例</title> </head> <body> <p>exception对象示例 <hr size="0"> <font size="-1"> 下面有错误发生，请将错误报告到：liuyo@sei.buaa.eud.cn </font> <% exception.printStackTrace(); StringWriter sout=new StringWriter(); PrintWriter pout=new PrintWriter(sout); exception.printStackTrace(pout); %> <pre> <%=sout.toString()%> </pre> </body></html>
