《JavaWeb项目开发教程》第二章代码 博客分类： 周国烛 jsp
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2024-03-21 12:28:04
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//使用JSP的脚本和指令
//chap02.sample2-1.jsp
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%!
//声明一个变量
String str = "Object-oriented programming";
//声明一个字符串截取的方法
public String subStr(String str){
if(str == null || "".equals(str))
return "";
if(str.length() > 20)
return str.substring(0, 20) + "...";
else
return str;
}
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>JSP中声明的使用</title>
</head>
<body>
<h3>原字符串是:<%=str %>></h3>
<h3>截取后字符串是:<%=subStr(str)%>></h3>
</body>
</html>
//chap02.sample2-2.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>JSP中表达式的使用</title>
</head>
<body>
今天是:<%=new Date() %>
</body>
</html>
//chap02.sample2-3.jsp
<%@ page language="java" import="java.util.*,java.text.*" pageEncoding="utf-8"%>
<html>
<head>
<title>输出当前时间</title>
</head>
<body>
欢迎光临! <br>今天是<br>
<%
SimpleDateFormat formater = new SimpleDateFormat("yyyy年MM月dd日");
String strCurrentTime = formater.format(new Date());
out.print(strCurrentTime);
%>
</body>
</html>
//chap02.sample2-4.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ include file = "/logo.html" %>
<html>
<body>
<br>
<CENTER><%@ include file = "/sample2_3.jsp" %></CENTER>
<hr/>
<CENTER><%@ include file = "/sample2_1.jsp" %></CENTER>
</body>
</html>
//chap02.asmple2_5.jsp
<%@ page language="java" import="java.util.*" errorPage = "sample2_6.jsp" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
大家都知道，零不能做除数<br>
在程序设计时，如果出现零作除数的现象，程序将产生异常<br>
我们可以指定一个JSP页面，由该页面来处理当前页面中抛出但没有捕获的任何异常<br>
下面我们在程序中设置一个除法异常，大家观察页面运行效果，提货errorPage属性的作用<br>
<%=100/0 %>
</body>
</html>
//chap02.asmple2_6.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<body>
您所看到的是sample2_6.jsp页面的处理页面!<br>
</body>
</html>
//chap02.asmple2_7.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
</head>
<body>
<jsp:include page = "/sample2_6.jsp"/>
<br/>
<CENTER><jsp:include page = "/sample2_3.jsp"/> </CENTER>
<hr/>
<CENTER><jsp:include page = "/sample2_1.jsp"/> </CENTER>
</body>
</html>
//chap02.asmple2_8.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>jsp:forward测试</title>
</head>
<body>
<h3><font color = "red">jsp:forward动作标签测试</font></h3>
<%
int i = (int)(Math.random() * 10);
if(i >= 5){
%>
<jsp:forward page = "sample2_1.jsp"></jsp:forward>
<%
}else
{
%>
<jsp:forward page = "sample2_3.jsp"></jsp:forward>
<%} %>
</body>
</html>
//chap02.asmple2_9.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head>
<title>注释测试</title>
</head>
<body>
<h2>注释测试</h2>
<!-- 在页面源代码中，这个HTML注释是看得见的 ！-->
<!-- 在页面源代码中，这个值为"hello"的表达式的HTML注释是看得见的! <%= new String("hello")%>
-->
<%--在页面源代码中，这个隐藏注释是看不见的! --%>
<%--在页面源代码中，隐藏注释即使包含了jsp表达式，在客户端也是看不到的!
<% = new String("hello")%> --%>
</body>
</html>