[Troubleshooting] SQLException: IO 異常: The Network Adapter could not establish the connection

錯誤訊息
SQLException: IO 異常: The Network Adapter could not establish the connection

成因
1. 資料庫沒有開啟, 所以無法連接上
2. 因為防火牆的原因, 該台連不上DBMS Server, 可先ping看看可否ping的到, ex. ping xxx.xxx.xxx.xxx 1521