1、对于Cookie的理解,在我看来其实就是存储客户端的一些个性化信息,简单一点的就是username、password之类的
2、在servlet中编程实现Cookie
code
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CookieServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doGet(req, resp);
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doPost(req, resp);
PrintWriter out=resp.getWriter();
Cookie ck=new Cookie("username","cjc");
//expired time 5 hours
ck.setMaxAge(3600*5);
resp.addCookie(ck);
Cookie[] cookies=req.getCookies();
out.println("<html>");
out.println("<head><title>Cookie</title></head>");
out.println("<body><font size=\"+4\"><b>");
if(cookies==null){
out.println("<hr><br>There is no cookie!");
}else{
out.println("<hr><br>");
for(int i=0;i<cookies.length;i++){
out.println("name:"+cookies[i].getName());
out.println("value:"+cookies[i].getValue());
}
}
out.println("</b></font></body>");
out.println("</html>");
}
}
第一次运行
第二次运行