Username & Password in JDBC Connection URL

Won't it take it from the connection URL?

I think No

You need to enter usrename & password.

Check: http://squirrel-sql.sourceforge.net/user-manual/quick_start.html#howtoconnect

section Connecting

From what I have seen, support for passing the username/password in the JDBC URL is inconsistent across Oracle JDBC Drivers.

Refer to this link, it will help you.

https://jdbc.postgresql.org/documentation/80/connect.html

For example, if you want to include username & password in the Postgres connection string.

jdbc:postgresql://postgres-10.4.cluster:5432/default?user=postgres&password=postgres

Thin driver Oracle's JDBC Thin driver uses Java sockets to connect directly to Oracle. It provides its own TCP/IP version of Oracle's SQL*Net protocol. Because it is 100% Java, this driver is platform independent and can also run from a Web Browser (applets). There are 2 URL syntax, old syntax which will only work with SID and the new one with Oracle service name.

Old syntax

jdbc:oracle:thin:@[HOST][:PORT]:SID

New syntax

jdbc:oracle:thin:@//[HOST][:PORT]/SERVICE

On new syntax SERVICE may be a oracle service name or a SID.

There are also some drivers that support a URL syntax which allow to put Oracle user id and password in URL.

jdbc:oracle:thin:[USER/PASSWORD]@[HOST][:PORT]:SID

jdbc:oracle:thin:[USER/PASSWORD]@//[HOST][:PORT]/SERVICE

source: http://www.orafaq.com/wiki/JDBC