java - 如何增加 Integer 对象的缓存大小

Question

阅读本文时 question

通过这条评论我知道我们可以增加缓存的大小

The recent version of Java 6 support changing the maximum cache value to greater than 127

我用谷歌搜索但没有找到相同的方法。

请帮忙。

Answer 1

例如 IntegerCache是这样说的:

/**
 * Cache to support the object identity semantics of autoboxing for values between 
 * -128 and 127 (inclusive) as required by JLS.
 *
 * The cache is initialized on first usage. During VM initialization the
 * getAndRemoveCacheProperties method may be used to get and remove any system
 * properites that configure the cache size. At this time, the size of the
 * cache may be controlled by the vm option -XX:AutoBoxCacheMax=<size>.

因此，要么使用 VM 参数，要么使用系统属性，例如:

-Djava.lang.Integer.IntegerCache.high=256

启动 JVM 时。