java中整数常量池(-128~127)上限如何调整？

Integer a = 500, b = 500;
System.out.println(a == b);//false
a = 100;
b = 100;
System.out.println(a == b);//true

Integer a = 500, b = 500;
System.out.println(a == b);

    /**
     * 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.  The size of the cache
     * may be controlled by the {@code -XX:AutoBoxCacheMax=<size>} option.
     * During VM initialization, java.lang.Integer.IntegerCache.high property
     * may be set and saved in the private system properties in the
     * sun.misc.VM class.
     */

    private static class IntegerCache {
       // ...
    }