一、理論

類加載時，不進行實例化，調用時才進行類的實例化。

二、代碼實現

public class LazyManPattern {

//1.構造方法私有化

private LazyManPattern(){}

//2.類加載時，不進行實例化

private static LazyManPattern lazyManPattern;

//3.創建實例化方法

public static LazyManPattern getLazyManPattern(){

if(lazyManPattern != null){

lazyManPattern = new LazyManPattern();

}

return lazyManPattern;

}

}

測試

public class Test {

public static void main(String[] args) {

//----------懶漢設計模式------------

LazyManPattern l1 = LazyManPattern.getLazyManPattern();

LazyManPattern l2 = LazyManPattern.getLazyManPattern();

if(l1 == l2){

System.out.println("l1和l2是相同的。");

}else{

System.out.println("l1和l2不是相同的。");

}

}

}