cookie应用

写Cookie

<%//从HTML表单中获取用户名

String username =request.getParameter(name);

Cookie user_name=new Cookie("cookie_name",username);//创建一个cookie

response.addCookie(user_name);

%>

读Cookie

<%

Cookie[]Cookies=request.getCookie();//创建一个Cookie对象数组

if(Cookie==null){

out.print("none any Cookie");

}

else{

for(int i=0;i<Cookies.length;i++){

//设立一个循环，来访问Cookie对象数组的每一个元素

if(Cookie[i].getName().equals("cookie_name") ) {

//判断元素的值是否为username中的值

out.print(Cookie[i].getValue()+"<br/>");

}

}

}

%>

<%

Cookie login=new Cookie("today","true");

login.setMaxAge(86400);//设置Cookie存在的时间

reponse.addCookie(login);

%>

inport javax.servlet.http.*;

public class LongLiveCookie extends Cookie{

public static final int SECONDS_PER_YEAR =60*60*24*365;

public LongLivedCookie(String name,String value){

super(name ,value);

setMaxAge(SECONDS_PER_YEAR);

}

}

<%

Cookie killMyCookie=new Cookie("mycookie",null);

killMyCookie.setMaxAge(0);

killMyCookie.setPath("/");

reponse.addCookie(killMyCookie);

%>

public static String getCookie Value(Cookie[]cookies, String cookieName,String defaultValue){

for(int i=0;i<cookies.length;i++){

Cookie cookie =cookies[i];

if(cookieName.equals(cookie.getName()))

return(cookie.getValue());

}

return(defaultValue);

}