获取ioc容器中bean的三种方式

分手后的思念是犯贱 2023-07-02 15:24 8阅读 0赞

xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
        
        <bean id="person1" class="com.stone.dome.model.Person">
            
            <property name="name" value="zs"></property>
            <property name="sex" value="男"></property>
            <property name="age" value="23"></property>
        </bean>
    
        <bean id="person2" class="com.stone.dome.model.Person">
            
            <property name="name" value="ls"></property>
            <property name="sex" value="男"></property>
            <property name="age" value="24"></property>
        </bean>
    
    </beans>

1.  根据bean的id获取

//  1.获取容器
            ApplicationContext ioc= new ClassPathXmlApplicationContext("ioc.xml");
    
     @Test
        public void testIoc1(){
            //  2.获取bean
            Person person=(Person) ioc.getBean("person1");
            System.out.println(person);
        }

1.  根据类型获取 （注意点 ： 获取的类型在该benas只能存在一个，存在多个时会出错）

@Test
        public void testIoc2(){
            //  2.获取bean
            Person person= ioc.getBean(Person.class);
            System.out.println(person);
        }

> 错误提示 （预期匹配一个 ，但是发现二个）org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type ‘com.stone.dome.model.Person’ available: expected single matching bean but found 2: person1,person2

1.  根据bean的id和类型获取

@Test
        public void testIoc3(){
            //  2.获取bean
            Person person= ioc.getBean("person2",Person.class);
            System.out.println(person);
        }