刚刚看完尚学堂的spirng动态代理视频,有一个问题求教一下:
public class Client { public static void main(String[] args) {
BeanFactory factory = new ClassPathXmlApplicationContext("applicationContext.xml");
UserManager userManager = (UserManager)factory.getBean("userManager");
userManager.addUser("张三", "123");
userManager.deleteUser(1);
}
}
以上代码中UserManager userManager = (UserManager)factory.getBean("userManager");
为什么要强转为接口UserManager呢,转为UserManagerimpl行吗??
public class Client { public static void main(String[] args) {
BeanFactory factory = new ClassPathXmlApplicationContext("applicationContext.xml");
UserManager userManager = (UserManager)factory.getBean("userManager");
userManager.addUser("张三", "123");
userManager.deleteUser(1);
}
}
以上代码中UserManager userManager = (UserManager)factory.getBean("userManager");
为什么要强转为接口UserManager呢,转为UserManagerimpl行吗??
解决方案 »
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