Spring 注解

使用注解实现IOC

注解的方式将bean 的定义信息和bean实现类结合在一起

@Component：实现bean组件的定义

@Repository：标注dao类

@Service：标注Service 业务类

@Controller：标注控制类

使用@Autowired注解 实现bean的自动装备，默认按类型匹配，可以使用@Qualifier指定bean的名称

    1 可以对类的成员变量进行标注

    2 也可以对方法的入参进行标注

使用注解的配置信息启动Spring容器

<context:component-scan base-package="cn.kitty.bean"></context:component-scan>

context：命名空间下的    component-scan ：扫描注解标注的类    base-package：指定需要的扫描的包 （包与包之间用逗号隔开）

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

    public Car() {
    }

    @Override
    public String toString() {
        return "Car{" +
                "color='" + color + '\'' +
                '}';
    }

    public Car(String color) {
        this.color = color;
    }

    public String getColor() {
        return color;
    }

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

 

@Component("student")
public class Student {
    @Value("12")
    private int age;
    @Value("kitty")
    private String name;
 /* @Resource(name="car")*///byname
    /*@Autowired
    @Qualifier("car")*/
 @Resource//bytype
    private Car car;

    public Car getCar() {
        return car;
    }

    public void setCar(Car car) {
        this.car = car;
    }

    public Student() {
    }

    public Student(int age, String name , Car car) {
        this.age = age;
        this.name = name;
        this.car = car;
    }

    @Override
    public String toString() {
        return "Student{" +
                "age=" + age +
                ", name='" + name + '\'' +
                ", car=" + car +
                '}';
    }



    public int getAge() {
        return age;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.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"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd">
    <!--配置包扫描器-->
          <context:component-scan base-package="cn.kitty.bean"></context:component-scan>
</beans>

test

public class TestZHUJIE {
    @Test
    public void TestZHUJIE(){
        ApplicationContext context=new ClassPathXmlApplicationContext("ApplicationContext.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student);
    }
}

使用注解来定义切面
使用注解来实现日志切面
使用注解定义前置增强和后置增强 
@Aspect
@Before
@AfterReturning
编写配置文件完成切面织入
<aop:aspectj -autoproxy />  启动对于@Aspectj注解的支持


接口

public interface UserService {

    public void select();
    public void update();
    public void insert();
    public  void delete();
}

实现类

public class UserServiceImpl implements UserService {
    public void select() {
       /* int result=5/0;*/
        System.out.println("select- ");
    }

    public void update() {
        System.out.println("update--- ");
    }

    public void insert() {
        System.out.println("insert-- ");
    }

    public void delete() {
        System.out.println("delete-- ");
    }
}

增强类Aspectj

@Aspect//打上@Aspect的类就是增强类  不用再实现 xxxxx
public class Aspectj {
 @Before("execution(* zhujie.*.select(..))")
public void beforeAdvice(){
    System.out.println("------before----");
}
    @AfterReturning("execution(public void zhujie.UserServiceImpl.select(..))")
    public void afterAdvice(){
        System.out.println("------after----");
    } 

ApplicationContest.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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <!--目标对象-->
    <bean id ="userservice" class="zhujie.UserServiceImpl"></bean>
    <!--增强，通知Advice-->
    <bean  class="zhujie.Aspectj"></bean>
    <!--aspectj 自动代理-->
    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>
</beans>

 

    test类

public class AspectjTest {
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("aspectj.xml");
        UserService service= (UserService) context.getBean("userservice");
      service.delete();
      service.insert();
      service.update();
      service.select();
    }
}