sql and&or用法 实现jsp邮箱或者用户名登录

     try {
            //链接字符串
             String driver ="com.mysql.jdbc.Driver";
            //加载驱动
             Class.forName(driver);
             //建立数据库连接
             Connection   con = (Connection) DriverManager.getConnection(url,user, dbpassword);

            if(con==null){
                System.out.println("can't open JDBConnection");
            }
            //sql语句
            String sql = "select * from user.user where (username=? or email=? )and password=?";

            PreparedStatement pstmt=(PreparedStatement) con.prepareStatement(sql); 
            pstmt.setString(1,this.Name); //第1个？字符的替换
            pstmt.setString(2,this.Name); //第2个？字符的替换
            pstmt.setString(3,this.Password);//第3个？字符的替换
            //pstmt.setString(4,this.Password);//第4个？字符的替换
            System.out.println(sql);
            System.out.println(getName());
            System.out.println(getPassword());
            ResultSet rs=pstmt.executeQuery();//执行语句后，产生单个结果集的语句
            if(rs.next())
            {
                System.out.println(rs.getString("username"));
                System.out.println("PASS");
                result=true;
            }
            else
            {
                System.out.println("FALL");
                result=false;
            }
            pstmt.close();//3个关闭PreparedStatement，ResultSet，Connection
            rs.close();
            con.close();

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return result;

总结：测试的时候看看是不是测试的用户名写错了= =