java分配的默认堆和栈各有多大？
------解决方案--------------------
不同的版本有不同的数字。拿 5.0来说：
-Xmsn
Specify the initial size, in bytes, of the memory allocation pool. This value must be a multiple of 1024 greater than 1MB. Append the letter k or K to indicate kilobytes, or m or M to indicate megabytes. The default value is 2MB. Examples:
-Xms6291456
-Xms6144k
-Xms6m
-Xmxn
Specify the maximum size, in bytes, of the memory allocation pool. This value must a multiple of 1024 greater than 2MB. Append the letter k or K to indicate kilobytes, or m or M to indicate megabytes. The default value is 64MB. Examples:
-Xmx83886080
-Xmx81920k
-Xmx80m