Java
Types
| type | note |
|---|---|
| byte | 8-bit signed two's complement integer |
| short | 16-bit signed two's complement integer |
| int | 32-bit signed two's complement integer |
| long | 64-bit two's complement integer |
| float | single-precision 32-bit IEEE 754 floating point |
| double | double-precision 64-bit IEEE 754 floating point |
| boolean | the size isn't precisely defined |
Numeric literals
You can use underscore characters in SE7+
example: long hexBytes = 0xFF_CC_DA_B5;
AES intrinsics
Requires Java 8 and Intel 2010+ Westmere
-XX:+UseAES -XX:+UseAESIntrinsics
Zero copy
Avoid copying the file data across user/kernel boundary, instead have the kernel put the file in a buffer and use DMA to pass the data directly.
https://www.ibm.com/developerworks/linux/library/j-zerocopy/