设计模式-单例模式

常见的单例模式-几种实现方法

注意构造函数，要用private加以修饰

恶汉-静态变量-线程安全

public class StaticSingleton {
    private static StaticSingleton staticSingleton = new StaticSingleton();
    private StaticSingleton() {}

    public static StaticSingleton getSingleton() {
        return staticSingleton;
    }
}

恶汉-静态代码块-线程安全

public class EHanSingleStatic {

    private static EHanSingleStatic singleton;
    private EHanSingleStatic(){}

    static {
        singleton = new EHanSingleton();
    }

    public static getInstance() {
        return singleton;
    }
}

懒汉-synchronized-现成安全

public class Singleton {

    pr