As far as which specific character sets are available, your runtime determines the complete set. Every Java programming implementation, however, must support the following encodings.
至于哪些特定的字符集可用，您的运行时将确定整个字符集。
2
A 64-bit runtime USES 64-bit Pointers (native address references), so the same Java object on 64-bit takes up more space than an object containing the same data on 32-bit.
位运行时使用64位指针(本机地址引用)，因此64位运行时中的相同对象会占用更多的空间。
3
Reflection is commonly used by programs which require the ability to examine or modify the runtime behavior of applications running in the Java virtual machine.