Memory usage of Java

用JDK自带的api计算size，每次都会有个多余的12，看了这些文档终于知道了

 

1：Memory usage of Java Strings and string-related objects

http://www.javamex.com/tutorials/memory/string_memory_usage.shtml

 

 

2：Memory usage of Java objects: general guide

http://www.javamex.com/tutorials/memory/object_memory_usage.shtml

 

 

3 How to calculate the memory usage of a Java array

http://www.javamex.com/tutorials/memory/array_memory_usage.shtml

 

 

4：Memory usage of Java Strings and string-related objects

http://www.javamex.com/tutorials/memory/string_buffer_memory_usage.shtml

评论

2 楼 vavi 2012-10-08  

啊 明白我错在哪里了 

1 楼 vavi 2012-10-07  

请教个问题,String内存大小是如何计算的?
multiply the number of characters of the String by two;
add 38;
if the result is not a multiple of 8, round up to the next multiple of 8;
the result is generally the minimum number of bytes taken up on the heap by the String.
我只能这样算: ojbect head  为 8 bytes
            3个 int       为 3*4 = 12 bytes
            1个char[]     为 12
不考虑char[]大小的话,为 8+12+12=32 bytes(不是38个字节), 还有6个字节那里去了??