Java How to test Int, char, boolean the number of bytes?

C / C + + can be sizeof
Java, how to test. . .

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Reply:
Do not need to test it
And C / C + + different, java in the number of bytes int char boolean seemingly is fixed, independent of the hardware platform and system
int, 32-bit, 4-byte
char 16 bits, 2 bytes
boolen, 8 bit 1 byte
Reply:
It is not public API
Reply:
1L positive solution. Under JVM is fixed. JNI under reference C / C + + byte type.
Reply:
Thank you, I've found a way, JAVA there is a macro can be solved. .
Reply:

references, 4th Floor oldmtn reply:

thank you, I've found a way, JAVA there is a macro can be solved. .

very much like to know how will java inside macro?