jsp內置9個對象和4個作用域（一）

2019-11-06 06:24:21

字體：大中小

來源：轉載

供稿：網友

備注： jsp的forward跳轉界面指令，地址不變

target.jsp的文件

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><h1>服務器跳轉到targe.jsp界面</h1>java=<%=request.getParameter("java")%><br/>secret=<%=request.getParameter("secret") %><br/></body></html>pageContext對象，用的方法是：pageContext.setAttribute(“關鍵字”,”值”);和pageContext.getAttribute(“關鍵字”);<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><%//設置兩個page范圍的數據（key，value） pageContext.setAttribute("name","rocky"); pageContext.setAttribute("age", 10);%><%//取值 String name=(String)pageContext.getAttribute("name");int age=(Integer)pageContext.getAttribute("age");%><p>姓名：<%= name %></p><p>年齡：<%= age %></p></body></html>

2.request對象。常調用的方法是request.setAttribute(“key”,”value”);

3.response對象的方法用于客戶端跳轉界面。地址改變response.sendRedirect(“index.html”);

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import="java.util.* " %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><%//客戶端跳轉界面，地址改變為index.html，重定向response.sendRedirect("index.html");%></body></html><!DOCTYPE html><html><head><meta charset="UTF-8"><title>Insert title here</title></head><body><h1>hello.i miss you</h1></body></html>

4.session對象

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><%//設置兩個值，格式分別是key----value;session.setAttribute("Hero", "諸葛亮");session.setAttribute("skill","wisdom");session.setAttribute("position",1);%><h1>session設置完畢</h1></body></html><%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><%//取值String hero=(String)session.getAttribute("Hero");String skill=(String)session.getAttribute("skill");int position=(Integer)session.getAttribute("position");%><h1>hero是：<%=hero %></h1><h1>他的技能是：<%=skill %></h1><h1>他的風云榜單是：<%=position%></h1></body></html>

5.application對象：

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><%application.setAttribute("dream","enabled");application.setAttribute("action","ing...");%><p>application 設置完畢</p></body></html><%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><%//取值String dream=(String)application.getAttribute("dream");String action=(String)application.getAttribute("action");%><p>我的夢想是：<%=dream %></p><br/><p>我的行動是：<%=action%></p></body></html>

Cookie內容

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%@ page import="java.util.*"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><script type="text/Javascript"> function resetValue(){ document.getElementById("userName").value=""; document.getElementById("pwd").value=""; }</script><% String userName=null; String pwd=null; Cookie[] cookies=request.getCookies();//瀏覽器自帶的cookie for(int i=0;cookies!=null &&i<cookies.length;i++){ if(cookies[i].getName().equals("userNameAndPwd")){ userName=cookies[i].getValue().split("-")[0]; pwd=cookies[i].getValue().split("-")[1]; } } if(userName==null){ userName=""; } if(pwd==null){ pwd=""; }%></head><body><form action="userLogin.jsp" method="post"> <table> <tr> <td>用戶名：</td> <td><input type="text" id="userName" name="userName" value="<%=userName%>"/></td> </tr> <tr> <td>密碼：</td> <td><input type="passWord" id="pwd" name="pwd" value="<%=pwd %>" /></td> </tr> <tr> <td>記住密碼：</td> <td><input type="checkbox" id="remember" name="remember" value="remember-me"/></td> </tr> <tr> <td><input type="submit" value="登錄"/></td> <td><input type="button" value="重置" onclick="resetValue()"/></td> </tr> </table></form></body></html><%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%@ page import="javax.servlet.http.*"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title></head><body><% String userName=request.getParameter("userName"); // 獲取用戶名 String pwd=request.getParameter("pwd"); // 獲取密碼 String remember=request.getParameter("remember"); // 獲取記住密碼 if("remember-me".equals(remember)){ Cookie userNameAndPwd=new Cookie("userNameAndPwd",userName+"-"+pwd); userNameAndPwd.setMaxAge(1*60*60*24*7); // cookie記錄一個星期 response.addCookie(userNameAndPwd); // 保存cookie System.out.程序猿的記錄。。。