枚举单例

package myproject.javatest;

public enum SingletonEnum {

	INSTANCE;
	
	public static SingletonEnum getInstance(){
		return INSTANCE;
	}
	
	private Object o;
	
	public Object testObject(){
		if(o == null){
			o = new Object();
		}
		return o;
	}
	
	public static void main(String[] args) {
		if(SingletonEnum.getInstance().testObject() == SingletonEnum.getInstance().testObject()){
			System.out.println("OK!");
		}
	}
	
}