Spring - JavaConfig @Import示例

原文地址：https://mkyong.com/spring3/spring-3-javaconfig-import-example

通常，您会将一个大型Spring XML bean文件分割成多个小文件(按模块或类别分组)，以使其更易于维护和模块化。例如,

在Spring Java Config中，等效功能是@Import。

package com.mkyong.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;

@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {
}

1. Spring Beans

File : CustomerBo.java

package com.mkyong.core;

public class CustomerBo {

    public void printMsg(String msg) {
        System.out.println("CustomerBo : " + msg);
    }

}

File : SchedulerBo.java

package com.mkyong.core;

public class SchedulerBo {

    public void printMsg(String msg) {
        System.out.println("SchedulerBo : " + msg);
    }

}

2. @Configuration示例

File : CustomerConfig.java

package com.mkyong.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.mkyong.core.CustomerBo;

@Configuration
public class CustomerConfig {
    
    @Bean(name="customer")
    public CustomerBo customerBo(){
        return new CustomerBo();
    }
}

File : SchedulerConfig.java

package com.mkyong.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.mkyong.core.SchedulerBo;

@Configuration
public class SchedulerConfig {
    
    @Bean(name="scheduler")
    public SchedulerBo suchedulerBo(){
        return new SchedulerBo();
    }
    
}

3. @Import示例

使用@Import加载多个配置文件。

File : AppConfig.java

package com.mkyong.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;

@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {
}

4. 运行

package com.mkyong.core;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import com.mkyong.config.AppConfig;

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

        ApplicationContext context = new AnnotationConfigApplicationContext(
                AppConfig.class);

        CustomerBo customer = (CustomerBo) context.getBean("customer");
        customer.printMsg("Hello 1");

        SchedulerBo scheduler = (SchedulerBo) context.getBean("scheduler");
        scheduler.printMsg("Hello 2");

    }
}