How to fix error when connecting SQL Developer to Oracle xe 11.2?

Question

linux

Good day to all! I took up the study of servlets, they need an oracle database (this is important) and for several days now I have been trying to move from fighting it to sql itself. So you need to connect the database to sql developer, I get this

This

.

Status : Failure -Test failed: IO Error: The Network Adapter could not establish the connection

.
At what yesterday I did it, the database was connected, and today I stumbled over another rake, I decided to check whether what I did yesterday works, but it does not work.

Tell me what is the error or in which direction to dig?
Thanks in advance!

p.s. OS Fedora 21.

Answer 1

The problem was in the Oracle listener, which for some reason did not start with standard settings (which is strange because it started once), so the solution is described here . If in Russian then

So

by the address

/u01/app/oracle/product/11.2.0/xe/network/admin/listener.ora

лежит файл listener.ora внутри него нужно изменить строку KEY=EXTPROC_FOR_XE на строку KEY=EXTPROC0

Answer 2

There was the same error.
Treatment:
1) open the file C:\app\Computer\product\18.0.0\dbhomeXE\NETWORK\ADMIN\tnsnames.ora (this is the path for the "default" installation)
2) find the line with the value HOST = 192.168.0.73 ( I have this)
3) return to the error page and at the bottom of the Hostname field, replace the localhost value with 192.168.0.73 (you may have something else)
That's it!
All the best in your studies and work!

Answer 3

add the line AddVMOption -Duser.region=US to ~/.sqldeveloper/bin/sqldeveloper.conf