RFR: 8314063 : The socket is not closed in Connection::createSocket when t…

[Weibing Xiao]

Please refer to JDK-8314063.

The failure scenario is due to the setting of connection timeout. It is either too small or not an optimal value for the system. When the client tries to connect to the server with LDAPs protocol. It requires the handshake after the socket is created and connected, but it fails due to connection timeout and leaves the socket open. It is not closed properly due to the exception handling in the JDK code.

The change is adding a try/catch block and closing the socket in the catch block,  and the format of the code got changed consequently.

-------------

Commit messages:
 - remove the unused import
 - 8314063 : The socket is not closed in Connection::createSocket when the handshake failed for LDAP connection

Changes: https://git.openjdk.org/jdk/pull/15294/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15294&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8314063
  Stats: 286 lines in 3 files changed: 229 ins; 15 del; 42 mod
  Patch: https://git.openjdk.org/jdk/pull/15294.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15294/head:pull/15294

PR: https://git.openjdk.org/jdk/pull/15294