实例化bean的四种方法

标签：return 构造方法 class bean 实例 public 四种

方法一：用构造方法实例化bean

提供可靠的构造方法，不写默认调用无参构造方法

//配置
<bean id="bookDao" class="org.wcx.dao.impl.BookDaoImpl"/>

 

方法二：用静态工厂实例化bean

1 public class OrderDaoFactory {
2     public static OrderDao getOrderDao(){
3         return new OrderDaoImpl();
4     }
5 }

静态工厂

//配置
<bean id="orderDao" class="org.wcx.dao.factory.OrderDaoFactory" factory-method="getOrderDao"/>

 

方法三：用实例工厂实例化bean

public class UserDaoFactory {
    public UserDao getUserOrder(){
        return new UserDaoImpl();
    }

}

实例工厂

//配置
<bean id="userDaoFactory" class="org.wcx.dao.factory.UserDaoFactory" />
<bean id="userDao" factory-bean="userDaoFactory" factory-method="getUserOrder"/>

 

方法四：FactoryBean

 1 public class UserDaoFactoryBean implements FactoryBean<UserDao> {
 2 
 3     @Override
 4     public UserDao getObject() throws Exception {
 5         return new UserDaoImpl();
 6     }
 7 
 8     @Override
 9     public Class<?> getObjectType() {
10         return UserDao.class;
11     }

FactoryBean

//配置
<bean id="userDao" class="org.wcx.dao.factory.UserDaoFactoryBean"/>

 

标签：return,构造方法,class,bean,实例,public,四种
From： https://www.cnblogs.com/wahahahhh/p/17081535.html