guava servicemanager 集成guice 使用
实例代码
- servicemanager
public class MyServiceManagerProvider implements Provider<ServiceManager> {
// 此处初始化一个AbstractService 实际上是多余的， ServiceManager 自带一个NoOpService
@Inject
Set<Service> services = Sets.<Service>newHashSet(new AbstractService() {
@Override
protected void doStart() {
}
@Override
protected void doStop() {
}
});
@Override
public ServiceManager get() {
return new ServiceManager(services);
}
}
- 注册
public class BootstrapModule extends AbstractModule {
@Override
protected void configure() {
Multibinder<Service> serviceMultibinderBinder = Multibinder.newSetBinder(binder(), Service.class);
serviceMultibinderBinder.addBinding().to(ServiceA.class);
serviceMultibinderBinder.addBinding().to(ServiceB.class);
bind(ServiceManager.class).toProvider(MyServiceManagerProvider.class).asEagerSingleton();;
}
}
- 使用
@Singleton
public class Init {
@Inject
private ServiceManager serviceManager;
public ServiceManager start(){
return serviceManager.startAsync();
}
}
- 启动
public static void main(String[] args) throws InterruptedException {
Injector injector = Guice.createInjector(new BootstrapModule());
Init init= injector.getInstance(Init.class);
ServiceManager serviceManager = init.start();
serviceManager.servicesByState().get(Service.State.RUNNING).stream().forEach(service -> System.out.println(service.isRunning()));
Thread.sleep(10000);
serviceManager.stopAsync();
Runtime.getRuntime().addShutdownHook(new Thread(() -> {
try {
serviceManager.awaitStopped(10, TimeUnit.SECONDS);
} catch (TimeoutException e) {
throw new RuntimeException(e);
}
}));
}
service 类型
使用中的一些问题
一般我们实现AbstractIdleService，对于定时任务实现AbstractScheduledService以及AbstractExecutionThreadService(单线程模式)
对于直接实现AbstractService的服务，需要自定编写线程管理服务，否则运行效果会不符合实际预期
参考实现
public class ServiceC extends AbstractService {
@Override
protected void doStart() {
MoreExecutors.directExecutor().execute(new Runnable() {
@Override
public void run() {
try {
System.out.println("servicec do starting");
notifyStarted();
} catch (Throwable t) {
notifyFailed(t);
}
}
});
}
@Override
protected void doStop() {
MoreExecutors.directExecutor().execute(new Runnable() {
@Override
public void run() {
try {
System.out.println("serviceb do stoping");
notifyStopped();
} catch (Throwable t) {
notifyFailed(t);
}
}
});
}
AbstractExecutionThreadService实际上的效果是执行之后如果状态是runing 的可以自己处理，比如循环数据处理，如果running 部分很快结束了，然后执行也就执行了
private final Service delegate =
new AbstractService() {
@Override
protected final void doStart() {
Executor executor =
MoreExecutors.renamingDecorator(
executor(),
new Supplier<String>() {
@Override
public String get() {
return serviceName();
}
});
executor.execute(
new Runnable() {
@Override
public void run() {
try {
startUp();
notifyStarted();
// If stopAsync() is called while starting we may be in the STOPPING state in
// which case we should skip right down to shutdown.
if (isRunning()) {
// 一般我们都是在isRunning 中进行业务处理
try {
AbstractExecutionThreadService.this.run();
} catch (Throwable t) {
try {
shutDown();
} catch (Exception ignored) {
// TODO(lukes): if guava ever moves to java7, this would be a good
// candidate for a suppressed exception, or maybe we could generalize
// Closer.Suppressor
logger.log(
Level.WARNING,
"Error while attempting to shut down the service after failure.",
ignored);
}
notifyFailed(t);
return;
}
}
shutDown();
notifyStopped();
} catch (Throwable t) {
notifyFailed(t);
}
}
});
}
参考使用
public class ServiceD extends AbstractExecutionThreadService {
@Override
protected void run() throws Exception {
System.out.println("ServiceD waitting to running");
// 此处也可能是一个循环，或者基于信号量
if(isRunning()){
System.out.println("ServiceD running");
}
}
@Override
protected void shutDown() throws Exception {
super.shutDown();
System.out.println("ServiceD shutdown");
}
@Override
protected void startUp() throws Exception {
super.startUp();
System.out.println("ServiceD startUp");
}
@Override
protected void triggerShutdown() {
super.triggerShutdown();
System.out.println("ServiceD triggerShutdown");
}
}
graylog 的实现 
说明
对于复杂服务状态管理我们基于guava servicemanager 是一个不错的选择，比如graylog 的service 就比较依赖servicemanager，对于我们进行服务管理是一个很不错的选择，值得使用
