注解配置spring

清疚 2022-03-22 01:52 214阅读 0赞

> ### 1.将对象注册到容器中：（四个的作用一样，只是让人能区别） ###

@Component("user")
    @Service("user")	//service
    @Controller("user")	//web
    @Repository("user")	//dao

### User.java ###

@Component("user")
    public class User {
    	private String name;
    	private Integer age;
    	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 Integer getAge() {
    		return age;
    	}
    
    	public void setAge(Integer age) {
    		this.age = age;
    	}
    
    	@Override
    	public String toString() {
    		return "User [name=" + name + ", age=" + age + ", car=" + car + "]";
    	}
    
    	
    	
    	
    }

### applicationContext.xml ###

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd ">
    	
    	//填写包名
    	<context:component-scan base-package="cn.itcast.bean"></context:component-scan>
    	
    </beans>

### demo ###

@Test
    	public void fun1() {
    		ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
    		User user = (User) ac.getBean("user");
    		
    		System.out.println(user.toString());
    	}

效果：（控制台）

![20190125120110977.png][]

> ### 2.修改对象的作用范围 ###

(1)

User.java

![20190125120541794.png][]

Demo

@Test
    	public void fun1() {
    		ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
    		User user1 = (User) ac.getBean("user");
    		User user2 = (User) ac.getBean("user");
    		User user3 = (User) ac.getBean("user");
    		System.out.println(user1==user3);
    		System.out.println(user1.toString());
    	}

效果：（控制台）

![2019012512064985.png][]

(2)

User.java

![20190125120738322.png][]

效果：（控制台）

![20190125120808417.png][]

> ###  3.值类型注入 ###

（1）通过反射的Field赋值

![20190125121049411.png][]

效果：（控制台）

![20190125121109553.png][]

（2）通过set方法赋值

![20190125121226916.png][]

效果：（控制台）

![20190125121240170.png][]

> ### 4.引用类型注入 ###

(1)

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd ">
    	
    	
    	<context:component-scan base-package="cn.itcast.bean"></context:component-scan>
    	
    	<bean name="car2" class="cn.itcast.bean.Car">
    		<property name="name" value="大奔"></property>
    	</bean>
    </beans>

Car.java

![20190125122059984.png][]

User.java（自动装配 ，使用@Qualifier注解告诉spring容器自动装配哪个）

![20190125121747227.png][]

效果：（控制台）

![20190125122130318.png][]

![20190125122201118.png][]

效果：（控制台）

![20190125122222629.png][]

(2)手动注入，指定哪个注入对象

![2019012512234638.png][]

效果：（控制台）

![20190125122431259.png][]

[20190125120110977.png]: /images/20220322/a2e8a5f850044537b0b8e3396bdd4d06.png
[20190125120541794.png]: /images/20220322/14c05a2383f74ea780e74ff01d10df78.png
[2019012512064985.png]: /images/20220322/04fc792d4fde4fc4892949d64cbc4b33.png
[20190125120738322.png]: /images/20220322/bb042a2312eb4aa882b2670c7b8dac87.png
[20190125120808417.png]: /images/20220322/ca80d0540aff4b21ad6d997345b5c7c2.png
[20190125121049411.png]: /images/20220322/72acfd219d9c49e4adc8283dc0be6517.png
[20190125121109553.png]: /images/20220322/20672e181cce4a908f44e98c09b4629f.png
[20190125121226916.png]: /images/20220322/88220a8136574cc3a437faf71b8ab1dd.png
[20190125121240170.png]: /images/20220322/5235e6bdcf954664a062bcf79fe47f4b.png
[20190125122059984.png]: /images/20220322/6082da2868e3471e99e8b28d42d0317f.png
[20190125121747227.png]: /images/20220322/c53cc51de353461c8314bc643d6e2bb4.png
[20190125122130318.png]: /images/20220322/579545141cb54fef9ce5614506c97c9e.png
[20190125122201118.png]: /images/20220322/8884158d943846a6a96fc911494d0fac.png
[20190125122222629.png]: /images/20220322/54d09afa5932408f8cf073adce552d27.png
[2019012512234638.png]: /images/20220322/42974b841978420694f8e6d0b00e8840.png
[20190125122431259.png]: /images/20220322/de2e330f83a74875ad2bd7f00fbca7c3.png