【Spring】11 Bean 的配置方法(通过注释的方式)

特定组件：

@Component

基本注释，标识了一个受 Spring 管理的组件

@Respository

标识持久层组件

@Service

标识服务层(业务层)组件

@Controller

标识表现层组件

情况一：指定 Spring IOC 容器扫描的包

beans-annotation.xml

<beans>
	<!-- 指定 Spring IOC 容器扫描的包 -->
	<context:component-scan
            base-package="com.test.sping.beans.annotation">
    </context:component-scan>
</beans>

Main.java(com.test.sping.beans.annotation.Main)

public class Main {
    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");

        TestObject to = (TestObject) ctx.getBean("testObject");
        System.out.println(to);

        UserController userController = (UserController) ctx.getBean("userController");
        System.out.println(userController);

        UserService userService = (UserService) ctx.getBean("userService");
        System.out.println(userService);

        UserRepository userRepository = (UserRepository) ctx.getBean("userRepository");
        System.out.println(userRepository);

    }
}

情况二：通过 resource-pattern 指定扫描的资源

beans-annotation.xml

<beans>
	<!-- 指定 Spring IOC 容器扫描的包 -->
    <!-- 可以通过 resource-pattern 指定扫描的资源 -->
    <context:component-scan
            base-package="com.test.sping.beans.annotation"
            resource-pattern="repository/*.class">
    </context:component-scan>
</beans>

Main.java(com.test.sping.beans.annotation.Main)

public class Main {
    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");

        UserRepository userRepository = (UserRepository) ctx.getBean("userRepository");
        System.out.println(userRepository);

    }
}

情况三： 子节点指定排除哪些指定表达式的组件

beans-annotation.xml

<beans>
	<!-- context:exclude-filter 子节点指定排除哪些指定表达式的组件 -->
	<context:component-scan base-package="com.test.sping.beans.annotation">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository" />
    </context:component-scan>
</beans>

Main.java(com.test.sping.beans.annotation.Main)

public class Main {
    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");

        TestObject to = (TestObject) ctx.getBean("testObject");
        System.out.println(to);

        UserController userController = (UserController) ctx.getBean("userController");
        System.out.println(userController);

        UserService userService = (UserService) ctx.getBean("userService");
        System.out.println(userService);
    }
}

情况四：子节点指定包含哪些表达式的组件

beans-annotation.xml

<beans>
    <!-- context:include-filter 子节点指定包含哪些表达式的组件，该子节点需要 use-default-filters 配合使用 -->
    <context:component-scan
            base-package="com.test.sping.beans.annotation"
            use-default-filters="false">
    </context:component-scan>
</beans>

Main.java(com.test.sping.beans.annotation.Main)

public class Main {
    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");

        UserRepository userRepository = (UserRepository) ctx.getBean("userRepository");
        System.out.println(userRepository);

    }
}

情况五：子节点指定排除哪些指定表达式的组件 使用assignable（不包括什么）

beans-annotation.xml

<beans>
	<context:component-scan base-package="com.test.sping.beans.annotation">
        <context:exclude-filter type="assignable" expression="com.test.sping.beans.annotation.repository.UserRepository" />
    </context:component-scan>
</beans>

Main.java(com.test.sping.beans.annotation.Main)

public class Main {
    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");

        TestObject to = (TestObject) ctx.getBean("testObject");
        System.out.println(to);

        UserController userController = (UserController) ctx.getBean("userController");
        System.out.println(userController);

        UserService userService = (UserService) ctx.getBean("userService");
        System.out.println(userService);
    }
}

情况六：子节点指定包含哪些表达式的组件 使用assignable（只包括什么）

beans-annotation.xml

<beans>
	<context:component-scan
            base-package="com.test.sping.beans.annotation"
            use-default-filters="false">
        <context:include-filter type="assignable" expression="com.test.sping.beans.annotation.repository.UserRepository" />
    </context:component-scan>
</beans>

Main.java(com.test.sping.beans.annotation.Main)

public class Main {
    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");
        
        UserRepository userRepository = (UserRepository) ctx.getBean("userRepository");
        System.out.println(userRepository);
    }
}

其他文件

TestObject.java(com.test.sping.beans.annotation.TestObject)

package com.test.sping.beans.annotation;

import org.springframework.stereotype.Component;

@Component
public class TestObject {

}

UserController.java(com.test.sping.beans.annotation.controller.UserController)

package com.test.sping.beans.annotation.controller;

import org.springframework.stereotype.Controller;

@Controller
public class UserController {

    public void execute(){
        System.out.println("UserController execute...");
    }
}

UserRepository.java(com.test.sping.beans.annotation.repository.UserRepository)

package com.test.sping.beans.annotation.repository;

public interface UserRepository {

    void save();
}

UserRepositoryImpl.java(com.test.sping.beans.annotation.repository.UserRepositoryImpl)

package com.test.sping.beans.annotation.repository;

import org.springframework.stereotype.Repository;

@Repository("userRepository")
public class UserRepositoryImpl implements UserRepository {

    @Override
    public void save() {
        System.out.println("UserRepository Save...");
    }

}

UserService.java(com.test.sping.beans.annotation.Service.UserService)

package com.test.sping.beans.annotation.Service;

import org.springframework.stereotype.Service;

@Service
public class UserService {

    public void add(){
        System.out.println("UserService add...");
    }
}