using java as a programming language gets the job done, I know maybe some of you loathe java because of its slowness or its recent debacle due to oracle’s policy. but nonetheless I still love java because of its slogan “write once, run everywhere”.
and also Java IDEs like Eclipse are leading the way for programmers in making great apps. hence make java as the most commonly used programming language.
for the second rank there is C language, the reason why C is commonly used because C still sells lots of OS and devices. it works in hardware programming, because of its direct memory access using pointers. C is still the de facto language for embedded systems programming, as well as many performance critical applications. Many applications have chunks of C for optimized control over low level operations, while the majority of the logic is written in Java or something else. C is not a rare skill, it is just a rare skill in web programmers.