java - How does it possible that each jar works on linux and windows? -


i know java give powerful advantagte: java code compiled bytecode , bytecode executed jvm, hence java portability. however, there exists functions such implementation depends on operating system.

https://speakerdeck.com/raboof/jvm-hacking (4-th slide)
can see there system-depended c code. how work ? mean same jar using bind method can executed on windows , linux. after all, bind method on linux , windows can different (number of paramers, name , more).

can explain me?

it's jvm , runtime library magic.

pure java programs consist of bytecode, , jvm interprets or compiles bytecode, local cpu / os can execute it.

then there methods declared "native", , specific java runtime library windows x86 has implementation, x64 version has implementation, linux xyz has yet implementation , on. signature (number , type of parameters) of these native methods same on implementations, buildung common abstraction on windows/linux/macos functionalities wrap.

if need use native methods in code, must supply necessary implementations program (.dll, .so or whatever targetted systems need). luckily, that's necessary java library complete...


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