Java单例模式 - joyocaowei/joyocaowei.github.io GitHub Wiki

Code

// 饿汉模式
public class SingleTon {
	private static SingleTon INSTANCE = new SingleTon();

	private SingleTon() {
	}

	public static SingleTon getInstance() {
		return INSTANCE;
	}
}

// 延迟初始化占位(Holder)类模式
public class Resource {
	private Resource() {
	}

	private static class ResourceHolder {
		private static Resource INSTANCE = new Resource();
	}

	public static Resource getInstance() {
		return ResourceHolder.INSTANCE;
	}
}

Reference

深入理解单例模式