Use tnsnames.ora in Oracle SQL Developer

Question

I am evaluating Oracle SQL Developer.

My tnsnames.ora is populated, and a tnsping to a connection defined in tnsnames.ora work

Answer 1

I had the same problem, tnsnames.ora worked fine for all other tools but SQL Developer would not use it. I tried all the suggestions on the web I could find, including the solutions on the link provided here.
Nothing worked.

It turns out that the database was caching backup copies of tnsnames.ora like tnsnames.ora.bk2, tnsnames09042811AM4501.bak, tnsnames.ora.bk etc. These files were not readable by the average user.

I suspect sqldeveloper is pattern matching for the name and it was trying to read one of these backup copies and couldn't. So it just fails gracefully and shows nothing in drop down list.

The solution is to make all the files readable or delete or move the backup copies out of the Admin directory.