{"categories":["Java"],"author_name":"Naotsugu","url":"https://blog1.mammb.com/entry/20090907/1252333228","blog_title":"A Memorandum","author_url":"https://blog.hatena.ne.jp/Naotsugu/","provider_name":"Hatena Blog","type":"rich","blog_url":"https://blog1.mammb.com/","published":"2009-09-07 23:20:28","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fblog1.mammb.com%2Fentry%2F20090907%2F1252333228\" title=\"enum \u306b\u3088\u308b\u3088\u308a\u826f\u3044 Singleton - A Memorandum\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","image_url":null,"version":"1.0","title":"enum \u306b\u3088\u308b\u3088\u308a\u826f\u3044 Singleton","width":"100%","provider_url":"https://hatena.blog","height":"190","description":"Java 1.5 \u304b\u3089\u5c0e\u5165\u3055\u308c\u305fenum\u306b\u3088\u308a\u5b89\u5168\u306aSingleton\u304c\u4f5c\u6210\u53ef\u80fd\u3002\u5143\u30cd\u30bf\u306fEffective Java\u3060\u3063\u3051\u304b\uff1f \u5b9f\u88c5\u306f\u3053\u3093\u306a\u611f\u3058\u3002 import java.util.concurrent.atomic.AtomicLong; public enum Singleton { INSTANCE; private AtomicLong counter = new AtomicLong(); public Long countUp() { return counter.incrementAndGet(); } public Long getCount() { return count\u2026"}