Cookie的使用

一、成果

二、代码

package cookie;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class LoginCookie
 */
@WebServlet("/LoginCookie")
public class LoginCookie extends HttpServlet {
	private static final long serialVersionUID = 1L;

    /**
     * Default constructor. 
     */
    public LoginCookie() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset =utf-8" );
		PrintWriter out = response.getWriter();//创建输出流
		String UersName = request.getParameter("UersName");//获取输入的信息
		String Pswd = request.getParameter("PassWrd");
		String getNull = request.getParameter("checkBox");
		Cookie[] cookies = request.getCookies();
		if(cookies!=null)
		{
			for (Cookie cookie : cookies) {//遍历cookie
				String cookname = cookie.getName();
				if(cookname.equals("UersName"))
				{
					UersName = cookie.getValue();
					
				}
				if(cookname.equals("Pswd"))
				{
					Pswd = cookie.getValue();
				}
				
			}
			//response.sendRedirect("NewFile1.html");
		}
		
		if(UersName.equals("tom")&&Pswd.equals("123")&&getNull!=null)//判断是否正确和是否勾选自动登陆
		{
			Cookie cookie= new Cookie("UersName", UersName);//建立cookie
			Cookie cookie2 = new  Cookie("Pswd",Pswd);
			cookie.setMaxAge(2592000);//设置cookie的生存时间
			cookie2.setMaxAge(2592000);
			response.addCookie(cookie);
			response.addCookie(cookie2);//将建立的cookie存入
			response.sendRedirect("NewFile1.html");
		}
		else if(UersName.equals("tom")&&Pswd.equals("123")){
			//out.println("Weclome:"+ UersName);
			response.sendRedirect("NewFile1.html");
		}
		else {
			out.println("用户名或者密码错误");
			response.sendRedirect("NewFile.html");
		}
		
	} 

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

　　

package cookie;

import java.io.IOException;
import java.net.URLDecoder;

import javax.activation.URLDataSource;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Servlet Filter implementation class Fiter
 */
@WebFilter("/*")
public class Fiter implements Filter {

    /**
     * Default constructor. 
     */
    public Fiter() {
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see Filter#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
	}

	/**
	 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
	 */
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		// place your code here

		// pass the request along the filter chain
		//将请求转化为httpservletRequest请求
		HttpServletRequest  httpServletRequest = (HttpServletRequest) request;
		//将请求转化为httpservletResponse请求
		HttpServletResponse httpServletResponse  =( HttpServletResponse) response;
		//截获用户请求的地址
		String from = httpServletRequest.getServletPath();
		
		 if(from.equals("/NewFile.html"))
		{
			Cookie[] cookies = httpServletRequest.getCookies();
			//String uersname= null;
		//	String pswd = null;
			if(cookies!=null)
			{
				/*for (Cookie cookie : cookies) {//遍历cookie
					if(cookie.getName().equals("UersName"))
					{
						uersname =URLDecoder.decode(cookie.getValue(),"UTF-8");
					}
					else if (cookie.getName().equals("Pswd"))
					{
						pswd =URLDecoder.decode(cookie.getValue(),"utf-8") ;
					}
				}*/
				httpServletResponse.sendRedirect("LoginCookie");
			}
			//httpServletRequest.setAttribute("uersName", uersname);
			//httpServletRequest.setAttribute("password", pswd);
			chain.doFilter(request, response);//放行
		}
		 else {
			chain.doFilter(request, response);	
			}
		
	}

	/**
	 * @see Filter#init(FilterConfig)
	 */
	public void init(FilterConfig fConfig) throws ServletException {
		// TODO Auto-generated method stub
	}

}

　三、链接

链接：https://pan.baidu.com/s/1k54NTH7AG-QpvCZcug6HTg
提取码：rg50