Spring（四）注解

@Component     表示一个类是被Spring容器管理的一个Bean

@Value   表示给类的普通属性赋值

@Resource  给类的域属性赋值

@autoWire   给类的域属性赋值

后面两个的作用相同，但是他们来源的包不同

Resource是JDK提供的注解 import javax.annotation.Resource;

Spring提供的注解import org.springframework.beans.factory.annotation.Autowired；

import org.springframework.beans.factory.annotation.Qualifier;

那么怎么使用注解给类中的属性赋值呢

@Component("stu")
public class Student {
    @Value("wb")
    private String name;
    @Value("20")
    private String age;
    @Resource(name = "car")
    //@Autowired
    //@Qualifier(value = "car")
    private Car car;
    public Car getCar() {
        return car;
    } public void setCar(Car car) {
        this.car = car;
    }
    public String getName() {
        return name;
    }

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

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

@Component("car")
public class Car {
    @Value("black")
    private String color;

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }
}

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

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

<context:component-scan base-package="cn.Spring.t06annotationdi"></context:component-scan>

@Test
public void t2(){
    ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext05annotationdi.xml");
    Student stu= (Student) context.getBean("stu");
    System.out.println(stu.getName());
    System.out.println(stu.getAge());
    System.out.println(stu.getCar().getColor());

}