1.構造器實例化（默認無參構造）

2.靜態工廠方法實例化

3.實例工廠方法實例化

2.靜態工廠方法實例化

因為

Calendar calendar = Calendar.getInstance();
所有在sPRing中可以這樣創建對象
<bean id="cal" class="java.util.Calendar", factory-method="getInstance"></bean>
String str="applicationContext.xml";ApplicationContext context = new ClassPathXmlApplicationContext(str);Calendar caleandar = context.getBean("cal",Calendar.class);
3.實例工廠方法實例化
String str="ApplicationContext.xml";ApplicationContext context = new ClassPathXmlApplicationContext(str);Calendar caleandar = context.getBean("cal",Calendar.class);