1、Out對(duì)象
主要用來向客戶端輸出各種格式的數(shù)據(jù),并且管理應(yīng)用服務(wù)器上的輸出緩沖區(qū),Out對(duì)象的基類是javax.servlet.jsp.JspWriter類。
Out的主要方法:
out.println(DataType);或out.print(DataType);
實(shí)例:
<%@page language="java"
contentType="text/html;charset=gb2312"
import="java.util.*"
%>
<HTML>
<HEAD>
<TITLE> out對(duì)象使用實(shí)例</TITLE>
</HEAD>
<BODY>
<%
out.println(new Date().toLocaleString());
out.print("<BR>");
out.print("測試成功");
%>
</BODY>
</HTML>
2、Request對(duì)象
Request.setAttribute()與Request.getAttribute()方法實(shí)例(也可以使用forward建立請(qǐng)求關(guān)系):
主頁面:
<%@page language="java" contentType="text/html;charset=gb2312" %>
<%@ include file="1.jsp" %>
你剛才輸入的內(nèi)容是:
<%=request.getAttribute("gr")%>
引入頁面:
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
<HTML>
<HEAD>
<TITLE> request對(duì)象使用實(shí)例</TITLE>
</HEAD>
<BODY>
<% request.setAttribute("gr","123333");%>
</FORM>
</BODY>
</HTML>
Request.getParameter()方法實(shí)例
主頁面
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
<HTML>
<HEAD>
<TITLE> request.getParameter()方法使用實(shí)例</TITLE>
</HEAD>
<BODY>
<FORM METHOD=POST ACTION="2.jsp">
<INPUT TYPE="text" NAME="gr1"><BR>
<INPUT TYPE="text" NAME="gr2"><BR>
<INPUT TYPE="text" NAME="gr3"><BR>
<INPUT TYPE="submit" NAME="submit" value="提交">
<INPUT TYPE="reset" NAME="reset" value="清除">
</FORM>
</FORM>
</BODY>
</HTML>
引入頁面
<%@page language="java" contentType="text/html;charset=gb2312" %>
你剛才輸入的內(nèi)容是:<BR>
<%=request.getParameter("gr1")%><BR>
<%=request.getParameter("gr2")%><BR>
<%=request.getParameter("gr3")%><BR>
Request.getParameterName()方法實(shí)例
主頁面
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> request.getParameterName()方法使用實(shí)例</TITLE>
</HEAD>
<BODY>
<FORM METHOD=post ACTION="2.jsp">
<INPUT TYPE="text" NAME="gr1"><BR>
<INPUT TYPE="text" NAME="gr2"><BR>
<INPUT TYPE="text" NAME="gr3"><BR>
<INPUT TYPE="submit" value="提交">
<INPUT TYPE="reset" value="清除">
</FORM>
</FORM>
</BODY>
</HTML>
指向頁面
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
你剛才輸入的內(nèi)容是:<BR>
<%
Enumeration e=request.getParameterNames();
while(e.hasMoreElements()){
String parameterName=(String)e.nextElement();
String parameterValue=(String)request.getParameter(parameterName);
out.print("參數(shù)名稱:"+parameterName+"<BR>");
out.print("參數(shù)內(nèi)容:"+parameterValue+"<BR>");
}
%>
Request.getAttributeName()方法實(shí)例
主頁面:
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
<HTML>
<HEAD>
<TITLE> request.getAttributeName()方法使用實(shí)例</TITLE>
</HEAD>
<BODY>
<jsp:include page="2.jsp" flush="true"/>
<%
Enumeration e=request.getAttributeNames();
while(e.hasMoreElements()){
String attributeName=(String)e.nextElement();
String attributeValue=(String)request.getAttribute(attributeName);
out.print("變量名稱:"+attributeName);
out.print("變量內(nèi)容:"+attributeValue+"<BR>");
}
%>
</FORM>
</FORM>
</BODY>
</HTML>
轉(zhuǎn)向頁面
<%@page language="java" contentType="text/html;charset=gb2312" %>
<%
request.setAttribute("gr1","111");
request.setAttribute("gr2","222");
request.setAttribute("gr3","333");
%>
request.getRemoteAddr()方法實(shí)例:
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> request.getRemoteAddr()方法使用實(shí)例</TITLE>
</HEAD>
<BODY>
<B>你的IP地址:</B>
<B><%=request.getRemoteAddr()%></B>
</FORM>
</FORM>
</BODY>
</HTML>
3、Response對(duì)象
response.setHeader()方法網(wǎng)頁自動(dòng)刷新實(shí)例:
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
<HTML>
<HEAD>
<TITLE> response刷新頁面實(shí)例</TITLE>
</HEAD>
<BODY>
<%
response.setHeader("refresh","3");
out.println(new Date().toLocaleString());
%>
</BODY>
</HTML>
4、Application對(duì)象
在JSP服務(wù)器運(yùn)行時(shí)刻,僅有一個(gè)Application對(duì)象,它由服務(wù)器創(chuàng)建,也由服務(wù)器自動(dòng)清除,
不能被用戶創(chuàng)建和清除。我們只能創(chuàng)建這個(gè)Appliation對(duì)象的同步拷貝。
setAttribute(),getAttribute()和removeAttribute()方法實(shí)例:
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> Application對(duì)象方法實(shí)例</TITLE>
</HEAD>
<BODY>
<%
String username="rossini";
String password="126263";
application.setAttribute("username",username);
application.setAttribute("password",password);
out.println(application.getAttribute("username")+"<BR>");
out.println(application.getAttribute("password")+"<BR>");
application.removeAttribute("password");
out.println(application.getAttribute("password")+"<BR>");
%>
</BODY>
</HTML>
getAttributeNames()方法實(shí)例:
<%@page language="java" contentType="text/html;charset=gb2312" import="java.util.*" %>
<HTML>
<HEAD>
<TITLE> Application對(duì)象方法實(shí)例</TITLE>
</HEAD>
<BODY>
<%
String username="rossini";
String password="126263";
application.setAttribute("username",username);
application.setAttribute("password",password);
Enumeration enum=application.getAttributeNames();
while(enum.hasMoreElements()){
String attrName=(String)enum.nextElement();
out.println(attrName+"----"+application.getAttribute(attrName)+"<BR>");
}
%>
</BODY>
</HTML>
5、Session對(duì)象
當(dāng)用戶登陸網(wǎng)站,系統(tǒng)將為他生成一個(gè)獨(dú)一無二的Session對(duì)象,用以記錄改用戶的個(gè)人信息
,一旦改用戶退出網(wǎng)站,那么該Session對(duì)象將會(huì)注銷。Session對(duì)象可以綁定若干個(gè)人信息或
者Java對(duì)象,不同Session對(duì)象的同名變量是不會(huì)相互干擾的。
getValue(String name)、
putValue(String name)、
removeValue(String name)、
getValueNames() 、
getCreationTime()、
getId()、
getLastAccessedTime()、
getMaxInactiveInterval()、
setMaxInactiveInterval()方法:
主文件:
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> Session主頁面</TITLE>
</HEAD>
<BODY>
<%
String username="rossini";
String password="126263";
session.putValue("username",username);
session.putValue("password",password);
%>
<A HREF="2.jsp">指向第二頁</A>
</BODY>
</HTML>
轉(zhuǎn)向頁面1
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> Session轉(zhuǎn)向頁面1</TITLE>
</HEAD>
<BODY>
<%
String usr=(String)session.getValue("username");
String pwd=(String)session.getValue("password");
%>
<%=usr%><BR>
<%=pwd%><BR>
<%out.println("session create:"+session.getCreationTime());%><BR>
<%out.println("session id:"+session.getId());%><BR>
<%out.println("session last access:"+session.getLastAccessedTime());%><BR>
<%out.println("session 原來最大休眠時(shí)間:"+session.getMaxInactiveInterval());%><BR>
<%session.setMaxInactiveInterval(session.getMaxInactiveInterval()+1);%><BR>
<%out.println("session 最新最大休眠時(shí)間:"+session.getMaxInactiveInterval());%><BR
<%
String []name=session.getValueNames();
out.println("--------------"+"<BR>");
for(int i=0;i<name.length;i++)
{
out.println(session.getValue(name[i])+"<BR>");
}
%>
<%
session.removeValue("username");
%>
<A HREF="3.jsp">指向第三頁</A>
</BODY>
</HTML>
轉(zhuǎn)向頁面2
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> Session轉(zhuǎn)向頁面2</TITLE>
</HEAD>
<BODY>
<%
String usr=(String)session.getValue("username");
String pwd=(String)session.getValue("password");
%>
<%=usr%><BR>
<%=pwd%>
</BODY>
</HTML>
invalidate()方法將會(huì)將會(huì)清除當(dāng)前的session對(duì)象解除它和任何參數(shù)或者JAVA對(duì)象的綁定關(guān)系
簡單的JSP計(jì)數(shù)器
實(shí)例:
主頁面
<%@page language="java" contentType="text/html;charset=gb2312" %>
<HTML>
<HEAD>
<TITLE> JSP計(jì)數(shù)器 </TITLE>
</HEAD>
<BODY>
<div align="center"><font face="黑體" size="10">你是第<jsp:include page="11.jsp" flush="true"/> 位訪客</font> </div>
</BODY>
</HTML>
引入頁面
<%!protected int count=0;%>
<%=++count%>
JavaBean設(shè)計(jì)規(guī)范及實(shí)例
javaBean的設(shè)計(jì)規(guī)范:
一個(gè)javaBean類必須是一個(gè)公共類
一個(gè)javaBean類必須有一個(gè)空的構(gòu)造函數(shù)
一個(gè)javaBean類不應(yīng)有公共實(shí)例變量
持有值應(yīng)該通過一組存取方法(getXxx和setXxx)來訪問
實(shí)例:
package Show;
import java.sql.*;
public class DBconn{
private String sDBDriver="org.gjt.mm.mysql.Driver";
private String sConnStr="jdbc:mysql://10.1.1.79:3306/web?user=root&password=2676141";
private Connection conn=null;
private ResultSet rs=null;
public DBconn(){
try{
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e){
System.out.println("DBconn():"+e.getMessage());
}
}
public String getsConnStr(){
return sConnStr;
}
public void setsConnStr(String sConnStr){
this.sConnStr=sConnStr;
}
public void executeUpdate(String sql)throws Exception{
sql=new String(sql.getBytes("GBK"),"ISO8859_1");
try{
conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
stmt.executeUpdate(sql);
conn.close();
stmt.close();
}
catch(SQLException ex){
System.out.println("sql.executeUpdate:"+ex.getMessage());
}
}
public ResultSet executeQuery(String sql)throws Exception{
rs=null;
try{
sql=new String(sql.getBytes("GBK"),"ISO8859_1");
conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
conn.close();
stmt.close();
}
catch(SQLException ex){
System.out.println("sql.executeQuery:"+ex.getMessage());
}
return rs;
}
}
posted on 2005-10-24 22:10
zjw_albert 閱讀(131)
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