Java哈希表问题与对象参考 [英] Java Hash Table Issue with Object Reference

问题描述

我有一个哈希表，

HashTable ht = { (1, 1), (2, 1), (3, 1) }

现在，我像Integer foo = Integer(1)那样实现它，并像这样声明哈希表，

Now, I implement it like, Integer foo = Integer(1) and declare hash table like,

HashTable ht = { (foo, foo), (2, foo), (3, foo) }

现在，据我从此了解，这将减少JVM使用的堆空间.这是正确的吗?另一点是，在C语言中，我通常使用类似这样的结构，

Now, as per I understood from this, it will reduce heap space used by JVM. Is this correct ? Another point is that, in C, I usually use structure like,

HashTable ht = { (1, mem), (2, mem), (3, mem) } 
{ where mem is memory location (say 10) of 1 }

然后使用该位置访问值.现在，如果mem值小于Int(例如Byte)，则可以节省空间.但是，我不明白如何在Java中实现这一点. 或者还有其他减少哈希表空间的方法吗? (通过减少以Java的方式重复存储同一对象的方法).

And then use the location to access the value. Now, if mem value is less than Int (say Byte), I can save space. However, I don't understand how to implement this in Java. Or is there any other way to reduce space of the hash table ? (means by reducing repeatedly storing same object in Java's way).

推荐答案

使用Integer.valueOf()的最节省空间的方法是使用Integer.valueOf()，它使用flyweight设计模式来减少较小值的内存使用量.介于-128和(通常)127之间的值不需要额外的内存.

The most space-efficient way with Integers is to use Integer.valueOf(), which uses the flyweight design pattern to reduce the memory usage for small values. Values between -128 and (usually) 127 need no additional memory.

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