结论

@Order注解不能指定 bean 的加载顺序，它适用于 AOP 的优先级，以及将多个 Bean 注入到集合时，这些 bean 在集合中的顺序。

Order注解控制Component加载顺序

注意：组件类必须实现接口

package com.wenxiaowu.springboot.order.component;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * 测试组件order加载顺序(未实现接口，不能正确加载顺序)
 */
@SpringBootApplication(scanBasePackages = {"com.wenxiaowu.springboot.order.component"})
public class ComponentOrderTest {
    public static void main(String[] args) {
        System.out.println("ComponentOrderTest start.");
        SpringApplication.run(ComponentOrderTest.class, args);
        System.out.println("ComponentOrderTest end.");
    }
}

@Component
class Runner implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        System.out.println("The Runner start to initialize ...");
    }
}

@Component
@Order(2)
class OrderRunner1 implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        System.out.println("The OrderRunner1 start to initialize ...");
    }
}

@Component
@Order(1)
class OrderRunner2 implements CommandLineRunner {
    @Override
    public void run(String... args) throws Exception {
        System.out.println("The OrderRunner2 start to initialize ...");
    }
}

Order注解控制Service类加载顺序

package com.wenxiaowu.springboot.order.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.List;

/**
 * 测试组件order加载顺序
 */
@SpringBootApplication(scanBasePackages = {"com.wenxiaowu.springboot.order.service"})
public class ServiceOrderTest {
    public static void main(String[] args) {
        System.out.println("ServiceOrderTest start.");
        SpringApplication.run(ServiceOrderTest.class, args);
        System.out.println("ServiceOrderTest end.");
    }
}

@Component
class AfterRepairConsumer {
    @Autowired
    private List<RepairCreatePostConsumer> postConsumers;

    @PostConstruct
    public void run() {
        final String repairId = "1";
        if (postConsumers != null && postConsumers.size() > 0) {
            postConsumers.forEach(e -> e.postHandler(repairId));
        }
    }
}

interface RepairCreatePostConsumer {
    /**
     * 创建报修单后做什么
     */
    void postHandler(String repairId);
}

@Service
@Order(value = 3)
class SendEmail implements RepairCreatePostConsumer {
    @Override
    public void postHandler(String repairId) {
        System.out.println("为报修单" + repairId + "发送邮件");
    }
}

@Service
@Order(value = 2)
class SendInvoice implements RepairCreatePostConsumer {
    @Override
    public void postHandler(String repairId) {
        System.out.println("为报修单" + repairId + "发送发票");
    }
}

@Service
@Order(value = 1)
class SendMessage implements RepairCreatePostConsumer {
    @Override
    public void postHandler(String repairId) {
        System.out.println("为报修单" + repairId + "发送消息");
    }
}