servlet二次登陆

电玩女神 2023-06-20 12:56 19阅读 0赞

## servlet二次登陆 ##

package login;
    
    import java.io.IOException;
    import java.sql.SQLException;
    
    import javax.servlet.ServletContext;
    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 org.apache.commons.dbutils.QueryRunner;
    import org.apache.commons.dbutils.handlers.BeanHandler;
    
    import domain.User;
    import utils.JdbcUtils;
    
    /**
     * Servlet implementation class LoginServlet
     */
    @WebServlet("/login")
    public class LoginServlet extends HttpServlet {
        
    	private static final long serialVersionUID = 1L;
           @Override
        public void init() throws ServletException {
        
              int count = 0;
              this.getServletContext().setAttribute("count", count);
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
    		//1.获得用户名和密码
    		String uname = request.getParameter("uname");
    		String pwd = request.getParameter("pwd");
    		
    		//2.验证数据库总用户名和密码是否正确
    		 QueryRunner runner = new QueryRunner();
    		
    		User user =null;
    		try {
        
    		// runner=new QueryRunner JdbcUtils.getConnection();
    			user = runner.query(JdbcUtils.getConnection(),
    					"select * from user where uname=? and pwd=?", new BeanHandler<>(User.class),uname,pwd);
    		} catch (SQLException e) {
        
    			// TODO 自动生成的 catch 块
    			e.printStackTrace();
    		}
    		//根据返回的结果，判断
    		if(user!=null) {
        
    			//从servletcontext中取出count进行++运算
    			ServletContext countext = this.getServletContext();
    			Integer count =(Integer)countext .getAttribute("count");
    			count++;
    			//用户登录成功
    			response.getWriter().write(user.toString()+count);
    			countext.setAttribute("count", count);
    		}else {
        
    			//用户登录失败
    			response.getWriter().write("sorry");
    		}
    	}
    
    	/**
    	 * @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);
    	}
    
    }