Spring使用注解实现Bean的自动装配

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">

    <context:annotation-config/>

</beans>

xmlns:context="http://www.springframework.org/schema/context"
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd

<context:annotation-config/>

public class People {
@Autowired
private Cat cat;
@Autowired
private Dog dog;
private String 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;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

<context:annotation-config/>
<bean id="cat" class="com.lding.pojo.Cat"></bean>
<bean id="dog" class="com.lding.pojo.Dog"></bean>
<bean id="people" class="com.lding.pojo.People"></bean>

//如果允许对象为null，设置required = false,默认为true
@Autowired(required = false)
private Cat cat;

	<bean id="dog1" class="com.lding.pojo.Dog"/>
	<bean id="dog2" class="com.lding.pojo.Dog"/>
	<bean id="cat1" class="com.lding.pojo.Cat"/>
	<bean id="cat2" class="com.lding.pojo.Cat"/>

@Autowired
@Qualifier(value = "cat2")
private Cat cat;
@Autowired
@Qualifier(value = "dog2")
private Dog dog;

public class User {
//如果允许对象为null，设置required = false,默认为true
@Resource(name = "cat2")
private Cat cat;
@Resource
private Dog dog;
private String str;
}

<bean id="dog" class="com.lding.pojo.Dog"/>
<bean id="cat1" class="com.lding.pojo.Cat"/>
<bean id="cat2" class="com.lding.pojo.Cat"/>
<bean id="user" class="com.lding.pojo.User"/>

<bean id="dog" class="com.lding.pojo.Dog"/>
<bean id="cat1" class="com.lding.pojo.Cat"/>

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