Spring Bean自动装配入门到精通

public class Cat {
    public void shout(){
        System.out.println("喵喵叫...");
    }
}
public class Dog {
    public void shout()
    {
        System.out.println("汪汪叫...");
    }
}

public class People {
    @Resource
    private Cat cat;
    //如果显示的定义了Autowired的required为false
//    @Autowired(required = false)
//    @Qualifier(value = "dog222")
    @Resource
    private Dog dog;
    private String name;
    public String getName() {
        return name;
    }
    public void setName(@Nullable String name) {
        this.name = name;
    }
    public Cat getCat() {
        return cat;
    }
    public void setCat(Cat cat) {
        this.cat = cat;
    }
    public Dog getDog() {
        return dog;
    }
    public void setDog(Dog dog) {
        this.dog = dog;
    }
    @Override
    public String toString() {
        return "People{" +
                "cat=" + cat +
                ", dog=" + dog +
                ", name='" + name + '\'' +
                '}';
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="Http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    https://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<!--       http://www.springframework.org/schema/aop-->
<!--        http://www.springframework.org/schema/context/spring-aop-3.0.xsd">-->
    <context:annotation-config/>
    <bean id="cat" class="com.hc.pojo.Cat"/>
    <bean id="dog222" class="com.hc.pojo.Dog"/>
<!--    <bean id="dog111" class="com.hc.pojo.Dog"/>-->
<!--    //byName自动装配-->
<!--<bean id="people" class="com.hc.pojo.People" autowire="byName">-->
    <bean id="people" class="com.hc.pojo.People" >
<!--    <property name="name" value="小狂神呀"/>-->
<!--    <property name="dog" value="dog"/>-->
<!--    <property name="cat" value="cat"/>-->
</bean>
</beans>

public class MyTest {
    @Test
    public void test1()
    {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        People people = context.getBean("people", People.class);
        people.getDog().shout();
        people.getCat().shout();
    }
}

<!--<bean id="people" class="com.hc.pojo.People" autowire="byName">-->
<!--    <property name="name" value="小狂神呀"/>-->
<!--    <property name="dog" value="dog"/>-->
<!--    <property name="cat" value="cat"/>-->
</bean>

<bean id="dog" class="com.kuang.pojo.Dog"/>
<bean id="cat" class="com.kuang.pojo.Cat"/>
<bean id="cat2" class="com.kuang.pojo.Cat"/>
<bean id="user" class="com.kuang.pojo.User" autowire="byType">
   <property name="str" value="qinjiang"/>
</bean>

<context:annotation-config/>

public class User {
   @Autowired
   private Cat cat;
   @Autowired
   private Dog dog;
   private String str;
   public Cat getCat() {
       return cat;
  }
   public Dog getDog() {
       return dog;
  }
   public String getStr() {
       return str;
  }
}

<context:annotation-config/>
<bean id="dog" class="com.kuang.pojo.Dog"/>
<bean id="cat" class="com.kuang.pojo.Cat"/>
<bean id="user" class="com.kuang.pojo.User"/>

//如果允许对象为null，设置required = false,默认为true
@Autowired(required = false)
private Cat cat;
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<context:annotation-config/>
    <bean id="cat" class="com.hc.pojo.Cat"/>
    <bean id="dog222" class="com.hc.pojo.Dog"/>
<!--    <bean id="dog111" class="com.hc.pojo.Dog"/>-->

@Autowired
@Qualifier(value = "cat2")
private Cat cat;
@Autowired
@Qualifier(value = "dog2")
private Dog dog;
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public class People {
    @Resource
    private Cat cat;
    //如果显示的定义了Autowired的required为false
//    @Autowired(required = false)
//    @Qualifier(value = "dog222")
    @Resource
    private Dog dog;
    private String name;

 <bean id="cat" class="com.hc.pojo.Cat"/>
    <bean id="dog222" class="com.hc.pojo.Dog"/>
<!--    <bean id="dog111" class="com.hc.pojo.Dog"/>-->

<bean id="cat" class="com.hc.pojo.Cat"/>
    <bean id="dog222" class="com.hc.pojo.Dog"/>

@Resource
private Cat cat;
@Resource
private Dog dog;
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