基于注解的方式配置bean（基于注解配置Bean，基于注解来装配Bean的属性）
在classpath中扫描组件
组件扫描（component scanning）：Spring能够从classpath下自动扫描，侦测和实例化具有特定注解的组件。
特定组件包括：
[email protected]：基本注解，表示了一个受Spring管理的组件
[email protected]:标识持久层组件
[email protected]：标识服务层组（业务层）件
[email protected]:标识表现层组件
对于扫描到的组件，Spring有默认的命名策略：使用非限定类名，第一个字母小写，也可以在注解中通过value属性值标识组件的名称。
当在组件类上使用了特定的注解之后，还需要在Spring的配置文件中声明<context:component-scan>:
-base-package属性指定一个需要扫描的基类包，Spring容器将会扫描这个基类包里面及其子包中的所有类。
-当需要扫描多个包时，可以使用逗号分隔。
-如果仅希望扫描特定的类而不非基包下的所有类，可以使用resource-pattern属性过滤特定的类，示例：
<context:component-scan
base-package="com.logan.spring.beans"
resource-pattern="autowire/*.class"/>
-<context:include-filter>子节点表示要包含的目标类
-<context:exclude-filter>子节点表示要排除在外的目标
-<context:component-scan>下可以拥有若干个<context:include-filter>和<context:exclude-filter>子节点。
看代码
package logan.spring.study.annotation;
import org.springframework.stereotype.Component;
@Component
public class TestObject {
}
package logan.spring.study.annotation.repository;
import org.springframework.stereotype.Repository;
@Repository("userRepository")
public class UserRepositoryImpl implements UserRepository {
@Override
public void save() {
// TODO Auto-generated method stub
System.out.println("UserRepository Save...");
}
}
package logan.spring.study.annotation.service;
import org.springframework.stereotype.Service;
@Service
public class UserService {
public void add(){
System.out.println("UserService add...");
}
}
package logan.spring.study.annotation.controller;
import org.springframework.stereotype.Controller;
@Controller
public class UserController {
public void execute(){
System.out.println("UserController execute...");
}
}
配置文件
<?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-4.3.xsd">
<context:component-scan base-package="logan.spring.study.annotation"></context:component-scan>
</beans>
package logan.spring.study.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import logan.spring.study.annotation.controller.UserController;
import logan.spring.study.annotation.repository.UserRepository;
import logan.spring.study.annotation.service.UserService;
public class Main {
public static void main(String[] args) {
System.out.println(1);
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");
System.out.println(2);
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);
}
}
package logan.spring.study.annotation.repository;
public interface UserRepository {
void save();
}
返回的结果为
五月 24, 2017 10:25:12 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh 信息: Refreshing org[email protected]42110406: startup date [Wed May 24 22:25:11 CST 2017]; root of context hierarchy 五月 24, 2017 10:25:12 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions 信息: Loading XML bean definitions from class path resource [beans-annotation.xml] [email protected] [email protected] [email protected] [email protected]68d
这里使用的jar包有：
可以如下改规则：（通过resource-pattern指定扫描资源）
<?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-4.3.xsd">
<context:component-scan
base-package="logan.spring.study.annotation"
resource-pattern="repository/*.class" ></context:component-scan>
</beans>
package logan.spring.study.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import logan.spring.study.annotation.controller.UserController;
import logan.spring.study.annotation.repository.UserRepository;
import logan.spring.study.annotation.service.UserService;
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);
}
}
输出的结果为：
五月 24, 2017 10:30:25 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh 信息: Refreshing org[email protected]42110406: startup date [Wed May 24 22:30:25 CST 2017]; root of context hierarchy 五月 24, 2017 10:30:25 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions 信息: Loading XML bean definitions from class path resource [beans-annotation.xml] [email protected]bfca
<context:include-filter>和<context:exclude-filter>子节点支持多种类型的过滤表达式：
| 类别 | 示例 | 说明 |
| annotation | ||
| assinable | ||
| aspecct | ||
| regex | ||
| custom |
时间： 2024-10-24 02:59:10