How to make a class’s constructor unit testable when its instantiating a Guice module in it?

I have the below mentioned class in a library module, which the clients will use to interact with database. I have a public constructor that takes a parameter from the user of this library, but the …

How to ensure thread safety of utility static method?

Is there any general way or rules exits by which we can ensure the thread safety of static methods specifically used in various Utility classes of any applications. Here I want to specifically point …