Java SPI机制

public interface Calc {

    Logger logger = LoggerFactory.getLogger(Calc.class);

    Object calc(int calcType);

}

public class SinCalc implements Calc {

    @Override

    public Object calc(int calcType) {

        Object value = Math.sin(calcType);

        logger.info("sin result: {}", value);

        return value;

    }

}

计算开方：

public class SqrtCalc implements Calc {

    @Override

    public Object calc(int calcType) {

        Object value = Math.sqrt(calcType);

        logger.info("sqrt result: {}", value);

        return value;

    }

}

@Component

public class SpiService {

    public Object execCalc(int value){

        ServiceLoader<Calc> loader = ServiceLoader.load(Calc.class);

        Iterator<Calc> iterator = loader.iterator();

        while (iterator.hasNext()) {

            return iterator.next().calc(value);

        }

        return null;

    }

    public static void main(String[] args) {

        new SpiService().execCalc(100);

    }

}

#org.windwant.spring.core.spi.service.SinCalc
org.windwant.spring.core.spi.service.SqrtCalc
#org.windwant.spring.core.spi.service.LogCalc