23 Spring过滤器组件自动扫描

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 。

package com.gp6.scanning.filter;

public class CustomerDao {
    @Override
    public String toString() {
        return "Hello , This is CustomerDao";
    }   
}

package com.gp6.scanning.filter;

import org.springframework.beans.factory.annotation.Autowired;

public class CustomerService  {
    @Autowired
    CustomerDao customerDao;

    public CustomerDao getCustomerDao() {
        return customerDao;
    }

    public void setCustomerDao(CustomerDao customerDao) {
        this.customerDao = customerDao;
    }

    @Override
    public String toString() {
        return "CustomerService [customerDAO=" + customerDao + "]";
    }
        
}

<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.gp6.scanning.filter" >

        <context:include-filter type="regex" 
                       expression="com.gp6.scanning.filter.*Dao.*" />

        <context:include-filter type="regex" 
                       expression="com.gp6.scanning.filter.*Service.*" />

    </context:component-scan>

</beans>

package com.gp6.scanning.filter;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    public static void main( String[] args ) {
        ApplicationContext context =  new ClassPathXmlApplicationContext("com/gp6/scanning/filter/applicationContext.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.gp6.scanning.filter" >
    <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.gp6.scanning.filter.*DAO.*" />        
</context:component-scan>