查看端口是否被占用，然后就可以kill掉这个进程
lsof -i tcp:8000
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
nc 96989 dcq 3u IPv4 0x8e23b71a14e7df21 0t0 TCP localhost:irdmi (LISTEN)查看端口是否被占用，然后就可以kill掉这个进程
lsof -i tcp:8000
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
nc 96989 dcq 3u IPv4 0x8e23b71a14e7df21 0t0 TCP localhost:irdmi (LISTEN)