Updated: Apr 16
if you are german, you might know the book java ist auch eine insel or in english java is also an island. it is a book for learning java. the hint in the book title implies that java is not only a programming language, it is also an island and a coffee.
back in year1991 java initially was named greentalk of the green project. later it was renamed to oak after an oak tree outside the office of the founder james gosling. finally in 1995 it got the today known name java. sun microsystems had to change the name because another company already had oak reserved as an trademark 
the same goes for jakarta ee, the enterprise version of java. it was former known as java ee and has been renamed to the today known name early 2018. jakarta is the greatest city and the capitol of indonesia and also a coffee. 
to be more precise, java is an espsresso bean. in the enterprise edition of java there are there two manageable and instantiable objects called cdi and ejb. both are used in a way for dependency injection (simplified). fully pronounced one talks about context and dependency injection beans (cdi beans) and enterprise java beans (ejbs). as one can see the name bean, as in java bean is a really reserved name in the java eco system.
in java one can package all classes and resources in an archive. there are three known variants: jar, war and ear. all of them are simple tar archives. jar typically is used for packaging executable jars or as dependencies of a bigger project or container. pictured, it's a simple glass container where one can keep his/her beans - a jar.
other projects feel infected by the idea, so does project lombok and names the project after another island in indonesia. the same idea had the company jetbrains, it developed an own programming language called kotlin. kotlin is an island, but not in indonesia. kotlin is located in saint petersburg.