Run with Java 17

[iluwatar]

This is part of the transition plan at https://github.com/iluwatar/java-design-patterns/wiki/19.-Java-17-transition. In this issue, we build the project using JDK 11 and try to run it with Java 17 runtime.

Acceptance criteria

• The project is built with JDK 11
• The pattern examples are executed with Java 17 runtime e.g. java -jar proxy.jar
• The errors that come up in the testing are fixed

[ArinCodes]

I want to help in this issue

[iluwatar]

Ok @ArinCodes

[rohitgautam16]

Can I help in this isssue ..?

[shubhig226]

I want to help in this issue

[robertvolkmann]

@iluwatar Could I work on this?

[iluwatar]

@ArinCodes I'll assign this issue to @robertvolkmann as well since this is high priority.