cookie

1.什么是cookie?

保存到客户端的一个文本文件。  javax.servlet.http.Cookie;

2.写cookie

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;

public class A1Cookie extends HttpServlet
{
	protected void doGet(HttpServletRequest req,HttpServletResponse resp) throws ServletException,java.io.IOException
	{
		Cookie c1=new Cookie("username","zhangsan");
		resp.addCookie(c1);

		Cookie c2=new Cookie("password","123");
		c2.setMaxAge(3600);
		resp.addCookie(c2);
		resp.setContentType("text/html");
		resp.getWriter().println("成功");
	}
}

　

2.cookie分为两种，长期还是临时--硬盘，内存（浏览器会话结束时）

3读cookie

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;

public class A2ReadCookie extends HttpServlet
{
	protected void doGet(HttpServletRequest req,HttpServletResponse resp) throws ServletException,java.io.IOException
	{
		Cookie[] cookies=req.getCookies();
		for(int i=0;i<cookies.length;i++)
		{
			resp.getWriter().println(cookies[i].getName());
		}

	}
}