Dear Experts,
I need your help.
oracle cloud is not connecting.
the following error pop...
java.sql.SQLRecoverableException: IO Error: could not resolve the connect identifier
Caused by: oracle.net.ns.NetException: could not resolve the connect identifier

I think it's hard to see it as a simple connection error
in SQLplus(sqlDeveloper), I confirmed that the connection is fine.
Also, if I run the same code on another laptop, the connection works fine.
and, if I run the same code on another idle(eclipse, intelliJ), same errors is occured.
what am i missing?