class Single {
private Single() {};//私有构造方法
private static Single s = new Single();
public static Single get() {
if(s == null) {
s = new Single();
}
return s;
}//懒汉式*/
/*
public static Single get() {
return s;
}//饿汉式*/
}
class hello {
public static void main(String[] args) throws IOException {
Single s = Single.get();
Single s2 = Single.get();
System.out.println(s == s2);
}
}