io.etcd.jetcd.Watch Java Examples

public static void main(String[] args) {
    Args cmd = new Args();

    JCommander.newBuilder().addObject(cmd).build().parse(args);

    CountDownLatch latch = new CountDownLatch(cmd.maxEvents);
    ByteSequence key = ByteSequence.from(cmd.key, StandardCharsets.UTF_8);
    Collection<URI> endpoints = Util.toURIs(cmd.endpoints);

    Watch.Listener listener = Watch.listener(response -> {
        LOGGER.info("Watching for key={}", cmd.key);

        for (WatchEvent event : response.getEvents()) {
            LOGGER.info("type={}, key={}, value={}", event.getEventType(),
                Optional.ofNullable(event.getKeyValue().getKey()).map(bs -> bs.toString(StandardCharsets.UTF_8)).orElse(""),
                Optional.ofNullable(event.getKeyValue().getValue()).map(bs -> bs.toString(StandardCharsets.UTF_8))
                    .orElse(""));
        }

        latch.countDown();
    });

    try (Client client = Client.builder().endpoints(endpoints).build();
        Watch watch = client.getWatchClient();
        Watch.Watcher watcher = watch.watch(key, listener)) {

        latch.await();
    } catch (Exception e) {
        LOGGER.error("Watching Error {}", e);
        System.exit(1);
    }
}
 

@Override
protected CompletableFuture<Void> doSubscribe(final ClusterBooking booking) {
    CompletableFuture<Void> future = new CompletableFuture<>();
    EtcdClusterBooking etcdBooking = (EtcdClusterBooking) booking;
    //先查询
    ByteSequence key = ByteSequence.from(etcdBooking.getPath(), UTF_8);
    //先查询，无异常后添加watcher，若结果不为空，通知FULL事件
    GetOption getOption = GetOption.newBuilder().withPrefix(key).build();
    client.getKVClient().get(key, getOption).whenComplete((res, err) -> {
        if (!isOpen()) {
            future.completeExceptionally(new IllegalStateException("controller is closed."));
        } else if (err != null) {
            logger.error(String.format("Error occurs while subscribe of %s, caused by %s. retry....", etcdBooking.getService(), err.getMessage()), err);
            future.completeExceptionally(err);
        } else {
            List<WatchEvent> events = new ArrayList<>();
            res.getKvs().forEach(kv -> events.add(new WatchEvent(kv, null, PUT)));
            etcdBooking.onUpdate(events, res.getHeader().getRevision(), FULL);
            //添加watch
            try {
                WatchOption watchOption = WatchOption.newBuilder().withPrefix(key).build();
                Watch.Watcher watcher = client.getWatchClient().watch(key, watchOption, etcdBooking);
                etcdBooking.setWatcher(watcher);
                future.complete(null);
            } catch (Exception e) {
                logger.error(String.format("Error occurs while subscribe of %s, caused by %s. retry....", etcdBooking.getService(), e.getMessage()), e);
                future.completeExceptionally(e);
            }
        }
    });
    return future;
}
 

@Override
protected CompletableFuture<Void> doUnsubscribe(final ClusterBooking booking) {
    EtcdClusterBooking etcdBooking = (EtcdClusterBooking) booking;
    Watch.Watcher watcher = etcdBooking.getWatcher();
    if (watcher != null) {
        watcher.close();
    }
    return CompletableFuture.completedFuture(null);
}
 

@Override
protected CompletableFuture<Void> doSubscribe(final ConfigBooking booking) {
    CompletableFuture<Void> future = new CompletableFuture<>();
    EtcdConfigBooking etcdBooking = (EtcdConfigBooking) booking;
    //先查询
    ByteSequence key = ByteSequence.from(etcdBooking.getPath(), UTF_8);
    //先查询，无异常后添加watcher，若结果不为空，通知FULL事件
    client.getKVClient().get(key).whenComplete((res, err) -> {
        if (!isOpen()) {
            future.completeExceptionally(new IllegalStateException("controller is closed."));
        } else if (err != null) {
            logger.error(String.format("Error occurs while subscribe of %s, caused by %s. retry....", etcdBooking.getInterface(), err.getMessage()), err);
            future.completeExceptionally(err);
        } else {
            List<WatchEvent> events = new ArrayList<>();
            res.getKvs().forEach(kv -> events.add(new WatchEvent(kv, null, PUT)));
            etcdBooking.onUpdate(events, res.getHeader().getRevision());
            //添加watch
            try {
                WatchOption watchOption = WatchOption.newBuilder().withPrefix(key).build();
                Watch.Watcher watcher = client.getWatchClient().watch(key, watchOption, etcdBooking);
                etcdBooking.setWatcher(watcher);
                future.complete(null);
            } catch (Exception e) {
                logger.error(String.format("Error occurs while subscribe of %s, caused by %s. retry....", etcdBooking.getInterface(), e.getMessage()), e);
                future.completeExceptionally(e);
            }
        }
    });
    return future;
}
 

@Override
protected CompletableFuture<Void> doUnsubscribe(final ConfigBooking booking) {
    EtcdConfigBooking etcdBooking = (EtcdConfigBooking) booking;
    Watch.Watcher watcher = etcdBooking.getWatcher();
    if (watcher != null) {
        watcher.close();
    }
    return CompletableFuture.completedFuture(null);
}
 

@Override
public void watch(final String key, final DataChangedEventListener dataChangedEventListener) {
    Watch.Listener listener = Watch.listener(response -> {
        for (WatchEvent each : response.getEvents()) {
            DataChangedEvent.ChangedType changedType = getEventChangedType(each);
            if (DataChangedEvent.ChangedType.IGNORED != changedType) {
                dataChangedEventListener.onChange(new DataChangedEvent(each.getKeyValue().getKey().toString(Charsets.UTF_8), each.getKeyValue().getValue().toString(Charsets.UTF_8), changedType));
            }
        }
    });
    client.getWatchClient().watch(ByteSequence.from(key, Charsets.UTF_8), listener);
}
 

@Test
public void assertWatchUpdate() {
    doAnswer(invocationOnMock -> {
        Watch.Listener listener = (Watch.Listener) invocationOnMock.getArguments()[1];
        listener.onNext(buildWatchResponse(WatchEvent.EventType.PUT));
        return mock(Watch.Watcher.class);
    }).when(watch).watch(any(ByteSequence.class), any(Watch.Listener.class));
    centerRepository.watch("key1", dataChangedEvent -> {
    });
    verify(watch).watch(any(ByteSequence.class), any(Watch.Listener.class));
}
 

@Test
public void assertWatchDelete() {
    doAnswer(invocationOnMock -> {
        Watch.Listener listener = (Watch.Listener) invocationOnMock.getArguments()[1];
        listener.onNext(buildWatchResponse(WatchEvent.EventType.DELETE));
        return mock(Watch.Watcher.class);
    }).when(watch).watch(any(ByteSequence.class), any(Watch.Listener.class));
    centerRepository.watch("key1", dataChangedEvent -> {
    });
    verify(watch).watch(any(ByteSequence.class), any(Watch.Listener.class));
}
 

@Test
public void assertWatchIgnored() {
    doAnswer(invocationOnMock -> {
        Watch.Listener listener = (Watch.Listener) invocationOnMock.getArguments()[1];
        listener.onNext(buildWatchResponse(WatchEvent.EventType.UNRECOGNIZED));
        return mock(Watch.Watcher.class);
    }).when(watch).watch(any(ByteSequence.class), any(Watch.Listener.class));
    centerRepository.watch("key1", dataChangedEvent -> {
    });
    verify(watch).watch(any(ByteSequence.class), any(Watch.Listener.class));
}
 

public Watch.Watcher getWatcher() {
    return watcher;
}
 

public void setWatcher(Watch.Watcher watcher) {
    this.watcher = watcher;
}
 

public Watch.Watcher getWatcher() {
    return watcher;
}
 

public void setWatcher(Watch.Watcher watcher) {
    this.watcher = watcher;
}
 

/**
 * 注册Client列表更新监听
 *
 * @param binaryLogConfig
 * @param opLogEventHandlerFactory
 */
private void registerMetaDataWatcher(BinaryLogConfig binaryLogConfig, OpLogEventHandlerFactory opLogEventHandlerFactory) {

    String namespace = binaryLogConfig.getNamespace();
    String binLogClientSet = binaryLogConfig.getBinLogClientSet();

    Watch watchClient = etcdClient.getWatchClient();
    watchClient.watch(
            ByteSequence.from(etcdKeyPrefixUtil.withPrefix(namespace).concat(Constants.PATH_SEPARATOR).concat(binLogClientSet), StandardCharsets.UTF_8),
            WatchOption.newBuilder().withNoDelete(true).build(),
            new Watch.Listener() {
                @Override
                public void onNext(WatchResponse response) {
                    List<WatchEvent> eventList = response.getEvents();
                    for (WatchEvent event : eventList) {
                        if (WatchEvent.EventType.PUT.equals(event.getEventType())) {

                            KeyValue currentKV = event.getKeyValue();
                            Set<ClientInfo> currentClientInfoSet = getClientInfos(currentKV);

                            currentClientInfoSet
                                    .stream()
                                    .collect(Collectors.groupingBy(ClientInfo::getDatabaseEvent))
                                    .forEach(opLogEventHandlerFactory::updateClientBatch);
                        }
                    }
                }

                @Override
                public void onError(Throwable throwable) {
                    log.error("Watch clientInfo list change error.", throwable);
                }

                @Override
                public void onCompleted() {
                    log.info("Watch clientInfo list change completed.");
                }
            }
    );

}