Service 实现 |

Service 实现

WildFly MSC Service

Service 的两个方法 start() 和 stop() 在实现是不能够有阻塞操作，start() 和 stop() 中不能有以下操作

连接或等待网络连接
Sleep
Wait on a condition
Wait on a count down latch
等待线程池终止或等待其他 Service
等待其他 Service 的状态变化

TrackerService start(), stop() 实现分别为启动和停止 tracker 线程：

public class TrackerService implements Service<TrackerService> {
    ...
    @Override
    public void start(StartContext context) throws StartException {
        OUTPUT.start();
    }

    @Override
    public void stop(StopContext context) {
        OUTPUT.interrupt();
    }
}

TrackerDeploymentService start(), stop() 实现分别为初始化和销毁变量：

public class TrackerDeploymentService implements Service<TrackerDeploymentService> {
    ...
    @Override
    public void start(StartContext context) throws StartException {
        isShowCool = true;
        deployments = Collections.synchronizedSet(new HashSet<String>());
        coolDeployments = Collections.synchronizedSet(new HashSet<String>());
    }

    @Override
    public void stop(StopContext context) {
        isShowCool = false;
        deployments.clear();
        coolDeployments.clear();
    }
}

Service 之间依赖注入

TrackerService 依赖 TrackerDeploymentService，它们之间的依赖注入如下

TrackerService 中添加 InjectedValue 属性

private final InjectedValue<TrackerDeploymentService> deploymentService = new InjectedValue<TrackerDeploymentService>();

TrackerService 启动时添加依赖说明

context.getServiceTarget()
       .addService(name, service)
       .addDependency(TrackerDeploymentService.NAME, TrackerDeploymentService.class, service.getDeploymentService())
       .setInitialMode(Mode.ACTIVE)
       .install();

完整关于 TrackerService 启动的代码参照 TypeAddHandler performRuntime() 方法。