聊聊dubbo的SpringContainer

序

本文主要研究一下dubbo的SpringContainer

Container

dubbo-2.7.2/dubbo-container/dubbo-container-api/src/main/java/org/apache/dubbo/container/Container.java

@SPI("spring")
public interface Container {

    /**
     * start method to load the container.
     */
    void start();

    /**
     * stop method to unload the container.
     */
    void stop();

}

• Container接口定义了start、stop方法

SpringContainer

dubbo-2.7.2/dubbo-container/dubbo-container-spring/src/main/java/org/apache/dubbo/container/spring/SpringContainer.java

public class SpringContainer implements Container {

    public static final String SPRING_CONFIG = "dubbo.spring.config";
    public static final String DEFAULT_SPRING_CONFIG = "classpath*:META-INF/spring/*.xml";
    private static final Logger logger = LoggerFactory.getLogger(SpringContainer.class);
    static ClassPathXmlApplicationContext context;

    public static ClassPathXmlApplicationContext getContext() {
        return context;
    }

    @Override
    public void start() {
        String configPath = ConfigUtils.getProperty(SPRING_CONFIG);
        if (StringUtils.isEmpty(configPath)) {
            configPath = DEFAULT_SPRING_CONFIG;
        }
        context = new ClassPathXmlApplicationContext(configPath.split("[,\\s]+"), false);
        context.refresh();
        context.start();
    }

    @Override
    public void stop() {
        try {
            if (context != null) {
                context.stop();
                context.close();
                context = null;
            }
        } catch (Throwable e) {
            logger.error(e.getMessage(), e);
        }
    }

}

• SpringContainer实现了Container接口，其start方法会创建ClassPathXmlApplicationContext，然后执行refresh及start方法；其stop方法执行ClassPathXmlApplicationContext的stop及close方法

Main

dubbo-2.7.2/dubbo-container/dubbo-container-api/src/main/java/org/apache/dubbo/container/Main.java

public class Main {

    public static final String CONTAINER_KEY = "dubbo.container";

    public static final String SHUTDOWN_HOOK_KEY = "dubbo.shutdown.hook";

    private static final Logger logger = LoggerFactory.getLogger(Main.class);

    private static final ExtensionLoader<Container> loader = ExtensionLoader.getExtensionLoader(Container.class);

    private static final ReentrantLock LOCK = new ReentrantLock();

    private static final Condition STOP = LOCK.newCondition();

    public static void main(String[] args) {
        try {
            if (ArrayUtils.isEmpty(args)) {
                String config = ConfigUtils.getProperty(CONTAINER_KEY, loader.getDefaultExtensionName());
                args = COMMA_SPLIT_PATTERN.split(config);
            }

            final List<Container> containers = new ArrayList<Container>();
            for (int i = 0; i < args.length; i++) {
                containers.add(loader.getExtension(args[i]));
            }
            logger.info("Use container type(" + Arrays.toString(args) + ") to run dubbo serivce.");

            if ("true".equals(System.getProperty(SHUTDOWN_HOOK_KEY))) {
                Runtime.getRuntime().addShutdownHook(new Thread("dubbo-container-shutdown-hook") {
                    @Override
                    public void run() {
                        for (Container container : containers) {
                            try {
                                container.stop();
                                logger.info("Dubbo " + container.getClass().getSimpleName() + " stopped!");
                            } catch (Throwable t) {
                                logger.error(t.getMessage(), t);
                            }
                            try {
                                LOCK.lock();
                                STOP.signal();
                            } finally {
                                LOCK.unlock();
                            }
                        }
                    }
                });
            }

            for (Container container : containers) {
                container.start();
                logger.info("Dubbo " + container.getClass().getSimpleName() + " started!");
            }
            System.out.println(new SimpleDateFormat("[yyyy-MM-dd HH:mm:ss]").format(new Date()) + " Dubbo service server started!");
        } catch (RuntimeException e) {
            logger.error(e.getMessage(), e);
            System.exit(1);
        }
        try {
            LOCK.lock();
            STOP.await();
        } catch (InterruptedException e) {
            logger.warn("Dubbo service server stopped, interrupted by other thread!", e);
        } finally {
            LOCK.unlock();
        }
    }

}

• Main的main方法首先加载配置的containers，然后挨个执行start方法；如果配置了shutdownHook则注册dubbo-container-shutdown-hook，挨个调用container的stop方法

小结

SpringContainer实现了Container接口，其start方法会创建ClassPathXmlApplicationContext，然后执行refresh及start方法；其stop方法执行ClassPathXmlApplicationContext的stop及close方法

doc

• SpringContainer