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第3章 JSP 内置对象
例子1(如图3.1所示)
Example3_1.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=green><FONT size=1>
<FORM action="tree.jsp" method=post name=form>
<INPUT type="text" name="boy">
<INPUT TYPE="submit" value="Enter" name="submit">
</FORM>
</FONT>
</BODY>
</HTML>
tree.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=green><FONT size=1>
<P>获取文本框提交的信息:
<%String textContent=request.getParameter("boy");
%>
<BR>
<%=textContent%>
<P> 获取按钮的名字:
<%String buttonName=request.getParameter("submit");
%>
<BR>
<%=buttonName%>
</FONT>
</BODY>
</HTML>
例子2(如图3.2所示)
Example3_2.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=cyan><FONT size=1>
<FORM action="Example3_2.jsp" method=post name=form>
<INPUT type="text" name="girl">
<INPUT TYPE="submit" value="Enter" name="submit">
</FORM>
<%String textContent=request.getParameter("girl");
double number=0,r=0;
if(textContent==null)
{textContent="";
}
try{ number=Double.parseDouble(textContent);
if(number>=0)
{r=Math.sqrt(number) ;
out.print("<BR>"+String.valueOf(number)+"的平方根:");
out.print("<BR>"+String.valueOf(r));
}
else
{out.print("<BR>"+"请输入一个正数");
}
}
catch(NumberFormatException e)
{out.print("<BR>"+"请输入数字字符");
}
%>
</FONT>
</BODY>
</HTML>
例子3 (如图3.3所示)
Example3_3.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=green><FONT size=1>
<FORM action="tree.jsp" method=post name=form>
<INPUT type="text" name="boy">
<INPUT TYPE="submit" value="提交" name="submit">
</FORM>
</FONT>
</BODY>
</HTML>
tree.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<MHML>
<BODY>
<P>获取文本框提交的信息:
<%String textContent=request.getParameter("boy");
byte b[]=textContent.getBytes("ISO-8859-1");
textContent=new String(b);
%>
<BR>
<%=textContent%>
<P> 获取按钮的名字:
<%String buttonName=request.getParameter("submit");
byte c[]=buttonName.getBytes("ISO-8859-1");
buttonName=new String(c);
%>
<BR>
<%=buttonName%>
</BODY>
</HTML>
例子4(如图3.4、3.5所示)
Example3_4.jsp:
<HTML>
<BODY bgcolor=cyan><FONT size=1>
<%@ page contentType="text/html;charset=GB2312" %>
<FORM action="tree2.jsp" method=post name=form>
<INPUT type="text" name="boy">
<INPUT TYPE="submit" value="enter" name="submit">
</FORM>
</FONT>
</BODY>
</HTML>
tree2.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="java.util.*" %>
<MHML>
<BODY bgcolor=cyan>
<Font size=1 >
<BR>客户使用的协议是:
<% String protocol=request.getProtocol();
out.println(protocol);
%>
<BR>获取接受客户提交信息的页面:
<% String path=request.getServletPath();
out.println(path);
%>
<BR>接受客户提交信息的长度:
<% int length=request.getContentLength();
out.println(length);
%>
<BR>客户提交信息的方式:
<% String method=request.getMethod();
out.println(method);
%>
<BR>获取HTTP头文件中User-Agent的值::
<% String header1=request.getHeader("User-Agent");
out.println(header1);
%>
<BR>获取HTTP头文件中accept的值:
<% String header2=request.getHeader("accept");
out.println(header2);
%>
<BR>获取HTTP头文件中Host的值:
<% String header3=request.getHeader("Host");
out.println(header3);
%>
<BR>获取HTTP头文件中accept-encoding的值:
<% String header4=request.getHeader("accept-encoding");
out.println(header4);
%>
<BR>获取客户的IP地址:
<% String IP=request.getRemoteAddr();
out.println(IP);
%>
<BR>获取客户机的名称:
<% String clientName=request.getRemoteHost();
out.println(clientName);
%>
<BR>获取服务器的名称:
<% String serverName=request.getServerName();
out.println(serverName);
%>
<BR>获取服务器的端口号:
<% int serverPort=request.getServerPort();
out.println(serverPort);
%>
<BR>获取客户端提交的所有参数的名字:
<% Enumeration enum=request.getParameterNames();
while(enum.hasMoreElements())
{String s=(String)enum.nextElement();
out.println(s);
}
%>
<BR>获取头名字的一个枚举:
<% Enumeration enum_headed=request.getHeaderNames();
while(enum_headed.hasMoreElements())
{String s=(String)enum_headed.nextElement();
out.println(s);
}
%>
<BR>获取头文件中指定头名字的全部值的一个枚举:
<% Enumeration enum_headedValues=request.getHeaders("cookie");
while(enum_headedValues.hasMoreElements())
{String s=(String)enum_headedValues.nextElement();
out.println(s);
}
%>
<BR>
<P> 文本框text提交的信息:
<%String str=request.getParameter("boy");
byte b[]=str.getBytes("ISO-8859-1");
str=new String(b);
%>
<BR>
<%=str%>
<BR> 按钮的名字:
<%String buttonName=request.getParameter("submit");
byte c[]=buttonName.getBytes("ISO-8859-1");
buttonName=new String(c);
%>
<BR>
<%=buttonName%>
</Font>
</BODY>
</HTML>
例子5(如图3.6所示)
Login1.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=cyan><Font size=1 >
<FORM action="login2.jsp" method=post >
<P>输入你的姓名:
<INPUT type="text" name="name" value="abc">
<BR>
<P>输入你的e-mail地址:
<INPUT type="text" name="address" value="ookk@sina.com">
<P>点击送出按钮:
<BR>
<INPUT TYPE="submit" value="送出" name=submit>
</FORM>
</FONT>
</BODY>
</HTML>
login2.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="java.util.*" %>
<HTML>
<BODY bgcolor=cyan><Font size=1 >
<%!Hashtable hashtable=new Hashtable();
public synchronized void putString(String s)
{ hashtable.put(s,s);
}
%>
<% String person_name=request.getParameter("name"),
name_found=null;
if(person_name==null)
{person_name="";
}
byte b[]=person_name.getBytes("ISO-8859-1");
person_name=new String(b);
name_found=(String)hashtable.get(person_name);
if(name_found==null)
{ String person_email=request.getParameter("address");
if(person_email==null)
{person_email="";
}
StringTokenizer fenxi=new StringTokenizer(person_email," @");
int n=fenxi.countTokens();
if(n>=3)
{out.print("<BR>"+"你输入的Email有不合法字符");
}
else
{ putString(person_name);
out.print("<BR>"+"您已经注册成功");
out.print("<BR>"+"您注册的名字是"+person_name);
}
}
else
{out.print("<BR>"+"该名字已经存在,请您换个名字");
}
%>
</FONT>
</BODY>
</HTML>
例子6(如图3.7所示)
radio.jsp:
<HTML>
<%@ page contentType="text/html;charset=GB2312" %>
<BODY bgcolor=cyan><Font size=1 >
<P>诗人李白是中国历史上哪个朝代的人:
<FORM action="answer.jsp" method=post name=form>
<INPUT type="radio" name="R" value="a">宋朝
<INPUT type="radio" name="R" value="b">唐朝
<INPUT type="radio" name="R" value="c">明朝
<INPUT type="radio" name="R" value="d" checked="ok">元朝
<BR>
<P>小说红楼梦的作者是:
<BR>
<INPUT type="radio" name="P" value="a">曹雪芹
<INPUT type="radio" name="P" value="b">罗贯中
<INPUT type="radio" name="P" value="c">李白
<INPUT type="radio" name="P" value="d">司马迁
<BR>
<INPUT TYPE="submit" value="提交答案" name="submit">
</FORM>
</FONT>
</BODY>
</HTML>
answer.jsp:
<HTML>
<%@ page contentType="text/html;charset=GB2312" %>
<BODY bgcolor=cyan><Font size=1 >
<% int n=0;
String s1=request.getParameter("R");
String s2=request.getParameter("P");
if(s1==null)
{s1="";}
if(s2==null)
{s2="";}
if(s1.equals("b"))
{ n++;}
if(s2.equals("a"))
{ n++;}
%>
<P>您得了<%=n%>分
</FONT>
</BODY>
</HTML>
例子7(如图3.8所示)
select.jsp:
<HTML>
<%@ page contentType="text/html;charset=GB2312" %>
<BODY bgcolor=cyan><Font size=1 >
<P>选择计算和的方式
<FORM action="sum.jsp" method=post name=form>
<Select name="sum" size=2>
<Option Selected value="1">计算1到n的连续和
<Option value="2">计算1到n的平方和
<Option value="3">计算1到n的立方和
</Select>
<P>选择n的值:<BR>
<Select name="n" >
<Option value="10">n=10
<Option value="20">n=20
<Option value="30">n=30
<Option value="40">n=40
<Option value="50">n=50
<Option value="100">n=100
</Select>
<BR><BR>
<INPUT TYPE="submit" value="提交你的选择" name="submit">
</FORM>
</FONT>
</BODY>
</HTML>
sum.jsp:
<HTML>
<%@ page contentType="text/html;charset=GB2312" %>
<BODY bgcolor=cyan><Font size=1 >
<% long sum=0;
String s1=request.getParameter("sum");
String s2=request.getParameter("n");
if(s1==null)
{s1="";}
if(s2==null)
{s2="0";}
if(s1.equals("1"))
{int n=Integer.parseInt(s2);
for(int i=1;i<=n;i++)
{sum=sum+i;
}
}
else if(s1.equals("2"))
{int n=Integer.parseInt(s2);
for(int i=1;i<=n;i++)
{sum=sum+i*i;
}
}
else if(s1.equals("3"))
{int n=Integer.parseInt(s2);
for(int i=1;i<=n;i++)
{sum=sum+i*i*i;
}
}
%>
<P>您的求和结果是<%=sum%>
</FONT>
</BODY>
</HTML>
例子8(如图3.9所示)
table.jsp:
<HTML>
<%@ page contentType="text/html;charset=GB2312" %>
<BODY>
<Table align="Center" Border>
<TR width=400>
<TH Align="Center">中间</TH>
<TH Align="Right">右</TH>
<TH Align="LEFT">左</TH>
<TD></TD>
<TD></TD>
</TR>
<TR >
<TH Valign="Top">数据靠向上沿</TH>
<TD Valign="Bottom">数据靠向下沿</TD>
<TD Valign="Bottom" Align="Center" >数据居中靠向下沿</TD>
</TR>
<TR >
<TD Valign="Top"> 你好</TD>
<TD Valign="Bottom">hello</TD>
<TD Valign="Bottom" Aligin="Center" >112334</TD>
</TR>
</Table>
</BODY>
</HTML>
例子9(如图3.10所示)
tableform.jsp:
<HTML>
<%@ page contentType="text/html;charset=GB2312" %>
<BODY bgcolor=cyan>
<Table align="left" Border>
<TR>
<TH width=250><FONT size=1>李白是哪个朝代的人?:</TH>
<TD width=220>
<FORM action="answer.jsp" method=post name=form>
<INPUT type="radio" name="R" value="a" ><FONT size=1>宋朝
<INPUT type="radio" name="R" value="b" ><FONT size=1>唐朝
<INPUT type="submit" name="g" value="送出">
</FORM>
</TD>
</TR>
<TR >
<TH><FONT size=1>输入数据:</TH>
<FORM action="answer.jsp" method=post name=form>
<TD> <INPUT type="text" name="R" value="a" size=20 >
</TD>
<TD> <INPUT type="submit" name="f" value="送出" >
</TD>
</Form>
</TR>
</Table>
</BODY>
</HTML>
例子10(如图3.12所示)
Example3_10.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=cyan><Font size=1 >
<P>我正在学习response对象的
<BR>setContentType方法
<P>将当前页面保存为word文档吗?
<FORM action="" method="get" name=form>
<INPUT TYPE="submit" value="yes" name="submit">
</FORM>
<% String str=request.getParameter("submit");
if(str==null)
{str="";
}
if(str.equals("yes"))
{response.setContentType("application/msword;charset=GB2312");
}
%>
</FONT>
</BODY>
</HTML>
例子11(如图3.13所示)
Example3_11.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY bgcolor=cyan><Font size=1 >
<P>您想使用什么方式查看文本文件A.txt?
<FORM action="tree3.jsp" method="post" name=form>
<INPUT TYPE="submit" value="word" name="submit1">
<INPUT TYPE="submit" value="excel" name="submit2">
</FORM>
</FONT>
</BODY>
</HTML>
tree3.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY>
<% String str1=request.getParameter("submit1");
String str2=request.getParameter("submit2");
if(str1==null)
{str1="";
}
if(str2==null)
{str2="";
}
if(str1.startsWith("word"))
{response.setContentType("application/msword;charset=GB2312");
out.print(str1);
}
if(str2.startsWith("excel"))
{response.setContentType("application/x-msexcel;charset=GB2312");
}
%>
<jsp:include page="A.txt">
</jsp:include>
</BODY>
</HTML>
例子12(如图3.14所示)
Example3_12.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="java.util.*" %>
<HTML>
<BODY bgcolor=cyan><Font size=1 >
<P>现在的时间是:<BR>
<% out.println(""+new Date());
response.setHeader("Refresh","5");
%>
</FONT>
</BODY>
</HTML>
例子13
Example3_13.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY>
<P>填写姓名:<BR>
<FORM action="tree4.jsp" method="get" name=form>
<INPUT TYPE="text" name="boy">
<INPUT TYPE="submit" value="Enter">
</FORM>
</BODY>
</HTML>
tree4.jsp:
<%@ page contentType="text/html;charset=GB2312" %>
<HTML>
<BODY>
<% String str=null;
str=request.getParameter("boy");
if(str==null)
{str="";
}
byte b[]=str.getBytes("ISO-8859-1");
str=new String(b);
if(str.equals(""))
{response.sendRedirect("Example3_13.jsp");
}
else
{out.print("欢迎您来到本网页!");
out.print(str);
}
%>
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