Java利用SPI实现解耦的示例详解

/**
 * @author Huang gen(kenfeng)
 * @description 自定义的appender接口
 * @Since 2021/02/21
 **/

public interface MyLogAppender {

    /**
     * 获取实现的appender
     * @return  返回新建的appender对象
     * */
    Appender getAppender();
}

/**
 * @author Huang gen(kenfeng)
 * @description 自定义的appender
 * @Since 2021/02/21
 **/
@Component
public class MeshLogAppender extends UnsynchronizedAppenderBase<ILoggingEvent> implements MyLogAppender,ApplicationContextAware {

    private ApplicationContext applicationContext;

    public MeshLogAppender(){ }

    @Override
    public Appender getAppender() {
        MeshLogAppender meshLogAppender = new MeshLogAppender();
        return meshLogAppender;
    }

    @Override
    protected void append(ILoggingEvent iLoggingEvent) {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String std = simpleDateFormat.format(new Date(Long.parseLong(String.valueOf(iLoggingEvent.getTimeStamp()))));
        String log = std + "\t" + iLoggingEvent.getLevel() +"\t"+"--- ["+ iLoggingEvent.getThreadName()+"]\t"+iLoggingEvent.getCallerData()[0]+":\t "+iLoggingEvent.getMessage();
        FlowMessage input = new FlowMessage();
        MeshFlowService meshFlowService = SandboxSystemServiceFactory.getService(MeshFlowService.class);
        Map<String, Object> body = new HashMap<>(2);
        body.put("log",log);
        input.setTenantCode(DefaultTenant.get());
        input.setAppCode("epoch");
        input.setFlowCode("log_broadcast");
        input.setBody(body);
        FlowMessage output = meshFlowService.process(input);
        if(!StringUtils.isEmpty(output.getErrorMessage())){
            throw new RuntimeException("发布日志时，广播失败");
        }
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
}

				ServiceLoader<MyLogAppender> myLoaderInterfaceServiceLoader = ServiceLoader.load(MyLogAppender.class);
        Iterator<MyLogAppender> myLoaderInterfaceIterator = myLoaderInterfaceServiceLoader.iterator();
        while (myLoaderInterfaceIterator.hasNext()){
            MyLogAppender myLoaderInterface = myLoaderInterfaceIterator.next();

            Appender newAppender = myLoaderInterface.getAppender();
            newAppender.setName("application");
            newAppender.setContext(loggerContext);
            newAppender.start();
            rootLogger.addAppender(newAppender);
        }