Listener refused the connection with the following error

发生错误情况：登陆死活登陆不上，说密码错误，可是密码又没错
tomcat下log日志报错如下：

Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found
The Connection descriptor used by the client was:
192.168.10.4:1521:orcl

上网搜索了下，解决方法如下：

select count(*) from v$process;--当前连接数
select value from v$parameter where name = 'processes' --数据库允许的最大连接数
--修改最大连接数:
alter system set processes = 500 scope = spfile;

修改最大的进程数后重启oracle数据库服务
可再查看下是否修改成功：

select value from v$parameter where name = 'processes'