Servlet Session Filter ajax 登录功能

1、login.html

    
    
    





    

        

            
登录
        
        

            

                
                
            
            

                
                
            
            

            
            

                登 入
            
        
    

2、LoginServlet

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "LoginServlet",value = "/LoginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        HttpSession session = request.getSession();
        if(username!=null&&password!=null&&username.equals("admin")&&password.equals("123456")){
            session.setAttribute("username",username);
            session.setAttribute("password",password);
            response.getWriter().print("1");
        }else {
            response.getWriter().print("0");
        }
    }
}

3、closeLogin()

退了


    function closeLogin() {
    $.ajax({
        type:"post",
        url:"CloseLoginServlet",
        data:{
            "close":"close"
        }
    });
    window.location.href="http://localhost:8080/pages/login.html";
}

4、CloseLoginServlet

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "CloseLoginServlet",value = "/CloseLoginServlet")
public class CloseLoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        HttpSession session = request.getSession();
        session.setAttribute("username","");
        session.setAttribute("password","");
    }
}

5、successFilter(可以定义多个Filter，在web.xml里定义再创建Filter类，比如完成统一设置编码的功能等)

import java.io.IOException;
 
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.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
 
public class successFilter implements Filter{
//建立一个过滤器对象用于实现对success.jsp页面当中的请求信息进行过滤操作
	@Override
	public void destroy() {
		System.out.println("进行过滤器对象的销毁操作");
	}
 
	@Override
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {
		System.out.println("执行过滤操作");
		HttpServletRequest request=(HttpServletRequest)req;//进行request对象的强制转化
		HttpServletResponse response = (HttpServletResponse)res;
		HttpSession session=request.getSession();//通过Httprequest对象来进行session对象的获取操作
		if(session.getAttribute("username")==null ||
				!session.getAttribute("username").equals("admin")) {
			response.sendRedirect("http://localhost:8080/pages/login.html");
		}
		System.out.println("过滤权限转交之前");
		chain.doFilter(req, res);//进行控制权限的转交操作
		System.out.println("过滤权限转交之后");
	}
 
	@Override
	public void init(FilterConfig arg0) throws ServletException {
		System.out.println("进行过滤器对象的初始化操作:");
	}
	
}

web.xml

  Archetype Created Web Application
  
    successFilter
    filter.successFilter
  
  
    successFilter
    /index.html