Spring过滤器组件自动扫描 - Spring教程
在这个Spring自动组件扫描的教程,您已经了解如何使Spring自动扫描您的组件。在这篇文章中,我们将展示如何使用组件过滤器自动扫描过程。
1.过滤组件 - 包含
参见下面的例子中使用Spring “过滤” 扫描并注册匹配定义“regex”,即使该类组件的名称未标注 @Component 。
DAO 层
package com.yiibai.customer.dao;
public class CustomerDAO
{
@Override
public String toString() {
return "Hello , This is CustomerDAO";
}
}
Service 层
package com.yiibai.customer.services;
import org.springframework.beans.factory.annotation.Autowired;
import com.yiibai.customer.dao.CustomerDAO;
public class CustomerService
{
@Autowired
CustomerDAO customerDAO;
@Override
public String toString() {
return "CustomerService [customerDAO=" + customerDAO + "]";
}
}
Spring 过滤
<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-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<context:component-scan base-package="com.yiibai" >
<context:include-filter type="regex"
expression="com.yiibai.customer.dao.*DAO.*" />
<context:include-filter type="regex"
expression="com.yiibai.customer.services.*Service.*" />
</context:component-scan>
</beans>
执行
package com.yiibai.common;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.yiibai.customer.services.CustomerService;
public class App
{
public static void main( String[] args )
{
ApplicationContext context =
new ClassPathXmlApplicationContext(new String[] {"Spring-AutoScan.xml"});
CustomerService cust = (CustomerService)context.getBean("customerService");
System.out.println(cust);
}
}
输出
CustomerService [customerDAO=Hello , This is CustomerDAO]
在这个XML过滤中,所有文件的名称中包含 DAO 或 Service(DAO., Services.) 单词将被检测并在 Spring 容器中注册。
2.过滤组件 - 不包含
另外,您还可以排除指定组件,以避免 Spring 检测和 Spring 容器注册。不包括在这些文件中标注有 @Service 。
<context:component-scan base-package="com.yiibai.customer" >
<context:exclude-filter type="annotation"
expression="org.springframework.stereotype.Service" />
</context:component-scan>
不包括那些包含DAO这个词组文件名。
<context:component-scan base-package="com.yiibai" >
<context:exclude-filter type="regex"
expression="com.yiibai.customer.dao.*DAO.*" />
</context:component-scan>