单例模式
饿汉式(由于调用时 对象已经在构造方法之前加载 耗资源)
class SignleTon{
private static SignleTon s1=new SignleTon();
private SignleTon() {
System.out.println("SignleTon");
}
public static SignleTon getSignleTon() {
return s1;
}
}
懒汉式
class SignleTon{
private static SignleTon s1=null;
private SignleTon() {
System.out.println("SignleTon");
}
public static SignleTon getSignleTon() {
if (s1==null) {
s1=new SignleTon();
}
return s1;
}
}
原文：https://www.cnblogs.com/tanlei-sxs/p/9932767.html