JAVAスレッド安全単例設計モードの怠け者式
class Bank{
private Bank(){}
private static Bank instance = null;
public static Bank getInstance(){
// :
// synchronized (Bank.class) {
// if(instance == null){
// instance = new Bank();
// }
// return instance;
// }
// :
if(instance == null){
synchronized (Bank.class) {
if(instance == null){
instance = new Bank();
}
}
}
return instance;
}
}
参考1尚シリコンバレー