创建Bean时,class属性必须指定,此时为静态工厂类. factory-method指定静态工厂方法名. 接口: public interface Being { public void testBeing(); } Dog类 public class Dog implements Being{ private String msg; public void setMsg(String msg) { this.msg = msg; } @Override public void testBe
public class Factory { public static Person staticCreate(){ Person p = new Person(); p.name="staticCreate"; return p; } public Person instanceCreate(){ Person p = new Person(); p.name="instanceCreate"; return p; } } public static void
7.7 创建Bean的3种方式 ① 调用构造器创建Bean. ② 调用静态工厂方法创建Bean. ③ 调用实例工厂方法创建Bean. 7.7.1 使用构造器创建Bean实例. 使用构造器来创建Bean实例是最常见的情况,如果不采用构造注入,Spring底层会调用Bean类的无参数构造器来创建实例,因此要求该Bean类提供无参数的构造器.在这种情况下,class元素是必须的(除非采用继承),class属性的值就是Bean实例的实现类. 如果不采用构造注入,Spring容器将使用默认的构造器来创建B
报错如下: Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not