Springboot自动获取接口实现

ServiceLoader加载接口实现步骤

1.编写接口

public interface CommunicationAdapterFactory {
    void setKernel(LocalKernel kernel);
    boolean providesAdapterFor(Vehicle vehicle);
    BasicCommunicationAdapter getAdapterFor(Vehicle vehicle);
}

2.编写实现

// 实现类 1
public final class LoopbackCommunicationAdapterFactory implements CommunicationAdapterFactory {
    @Override
    public void setKernel(LocalKernel kernel) {}

    @Override
    public boolean providesAdapterFor(Vehicle vehicle) {
        return true;
    }

    @Override
    public BasicCommunicationAdapter getAdapterFor(Vehicle vehicle) {
        return null;
    }
}

// 实现类 2
public final class MqttCommunicationAdapterFactory implements CommunicationAdapterFactory {

    @Override
    public void setKernel(LocalKernel kernel) {}
    
    @Override
    public boolean providesAdapterFor(Vehicle vehicle) {
        return true;
    }
    
    @Override
    public BasicCommunicationAdapter getAdapterFor(Vehicle vehicle) {
        return null;
    }
}

3.要在resources文件夹下创建文件夹 “META-INF/services”

在创建的文件夹下，将接口文件的引用作为文件名创建文件

4.将实现的接口文件引用作为文件内容放到文件中

com.mj.tcs.adapter.mqtt.MqttCommunicationAdapterFactory

5.实现加载

    public static void main(String[] args) {
        ServiceLoader<CommunicationAdapterFactory> factoryLoader = ServiceLoader.load(CommunicationAdapterFactory.class);
        for (CommunicationAdapterFactory factory : factoryLoader) {
            System.out.println(factory);
        }
    }