Java SPI mechanism

Service Provider Interfaces Services provides discovery, dynamic replacement of discovery mechanisms

Example:

An interface:

 Public Interface Calc {
    Logger Logger = Loggerfactory.getlogger (Calc.class);
    Object Calc (int calctype);
}

Two implementations:

To calculate the sin value:

 Public class Implements Calc {
    @Override
     Public Object Calc (int calctype) {
        Object value = Math.sin (Calctype);
        Logger.info ("sin Result: {}", value);
        return value;
    }
}

Calculate the root:

 Public class Implements Calc {
    @Override
     Public Object Calc (int calctype) {
        Object value = math.sqrt (Calctype);
        Logger.info ("sqrt result: {}", value);
        return value;
    }
}

A Service load class:

@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);
    }
}

A configuration file: classpath:meta-inf/services/xxx.xxx.Calc

Content: Feature classes that need to be loaded

such as:Xxx.xxx.SqrtCalc

The service load class executes, and the output calculates the root.

sample Application project: https://github.com/windwant/spring-boot-test

Official documents: https://docs.oracle.com/javase/tutorial/sound/SPI-intro.html

Java SPI mechanism