上一節(jié)講了從我們SpringBoot項(xiàng)目同步數(shù)據(jù)到SoulAdmin并將數(shù)據(jù)持久化到數(shù)據(jù)庫中，這一節(jié)

在數(shù)據(jù)持久化到數(shù)據(jù)庫中之后，SoulAdmin會(huì)通過Spring的ApplicationEventPublisher發(fā)送一個(gè)事件變更事件，繼承自org.springframework.context.ApplicationEvent

//org.dromara.soul.admin.listener.DataChangedEvent#DataChangedEvent
public class DataChangedEvent extends ApplicationEvent {

    private DataEventTypeEnum eventType;

    private ConfigGroupEnum groupKey;

    /**
     * Instantiates a new Data changed event.
     *
     * @param groupKey the group key
     * @param type     the type
     * @param source   the source
     */
    public DataChangedEvent(final ConfigGroupEnum groupKey, final DataEventTypeEnum type, final List<?> source) {
        super(source);
        this.eventType = type;
        this.groupKey = groupKey;
    }

    /**
     * Gets event type.
     *
     * @return the event type
     */
    DataEventTypeEnum getEventType() {
        return eventType;
    }

    @Override
    public List<?> getSource() {
        return (List<?>) super.getSource();
    }

    /**
     * Gets group key.
     *
     * @return the group key
     */
    public ConfigGroupEnum getGroupKey() {
        return this.groupKey;
    }

}

DataChangedEvent存在兩個(gè)屬性，eventType

//org.dromara.soul.common.enums.DataEventTypeEnum
//對(duì)應(yīng)著事件的類型
public enum DataEventTypeEnum {

    /**
     * delete event.
     */
    DELETE,

    /**
     * insert event.
     */
    CREATE,

    /**
     * update event.
     */
    UPDATE,

    /**
     * REFRESH data event type enum.
     */
    REFRESH,

    /**
     * Myself data event type enum.
     */
    MYSELF;
}

//org.dromara.soul.common.enums.ConfigGroupEnum
//對(duì)應(yīng)著配置分組，現(xiàn)在總共支持 APP_AUTH：配置，PLUGIN：插件，RULE：規(guī)則，SELECTOR：選擇器，META_DATA：元數(shù)據(jù) 
public enum ConfigGroupEnum {

    /**
     * App auth config group enum.
     */
    APP_AUTH,

    /**
     * Plugin config group enum.
     */
    PLUGIN,

    /**
     * Rule config group enum.
     */
    RULE,

    /**
     * Selector config group enum.
     */
    SELECTOR,

    /**
     * Meta data config group enum.
     */
    META_DATA;
}

接下來通過查詢org.dromara.soul.admin.listener.DataChangedEvent調(diào)用他的地方。定位到DataChangedEventDispatcher

DataChangedEventDispatcher 實(shí)現(xiàn)了ApplicationListener并且接收DataChangedEvent事件，通過GroupKey的類型做不同處理

//org.dromara.soul.admin.listener.DataChangedEventDispatcher
public class DataChangedEventDispatcher implements ApplicationListener<DataChangedEvent>, InitializingBean {
    private ApplicationContext applicationContext;

    private List<DataChangedListener> listeners;

    public DataChangedEventDispatcher(final ApplicationContext applicationContext) {
        this.applicationContext = applicationContext;
    }

  // 監(jiān)聽DataChangedEvent，并根據(jù)ConfigGroupEnum類型進(jìn)行不同的處理
    @Override
    @SuppressWarnings("unchecked")
    public void onApplicationEvent(final DataChangedEvent event) {
        for (DataChangedListener listener : listeners) {
            switch (event.getGroupKey()) {
                case APP_AUTH:
                    listener.onAppAuthChanged((List<AppAuthData>) event.getSource(), event.getEventType());
                    break;
                case PLUGIN:
                    listener.onPluginChanged((List<PluginData>) event.getSource(), event.getEventType());
                    break;
                case RULE:
                    listener.onRuleChanged((List<RuleData>) event.getSource(), event.getEventType());
                    break;
                case SELECTOR:
                    listener.onSelectorChanged((List<SelectorData>) event.getSource(), event.getEventType());
                    break;
                case META_DATA:
                    listener.onMetaDataChanged((List<MetaData>) event.getSource(), event.getEventType());
                    break;
                default:
                    throw new IllegalStateException("Unexpected value: " + event.getGroupKey());
            }
        }
    }

  // 將Spring代理的DataChangedListener注入到當(dāng)前類的listeners
    @Override
    public void afterPropertiesSet() {
        Collection<DataChangedListener> listenerBeans = applicationContext.getBeansOfType(DataChangedListener.class).values();
        this.listeners = Collections.unmodifiableList(new ArrayList<>(listenerBeans));
    }
}

接口DataChangedListener不同實(shí)現(xiàn)類有如下：

image.png

即對(duì)應(yīng)了現(xiàn)在Soul的四種數(shù)據(jù)同步方式：http長(zhǎng)輪訓(xùn)，Websocket，Nacos，Zookeeper

1.Zookeeper方式很簡(jiǎn)單，就是依賴Zookeeper的watch機(jī)制，SoulAdmin在啟動(dòng)的時(shí)候?qū)?shù)據(jù)全量同步到Zookeeper，之后變化增量更新數(shù)據(jù)。

image.png

2. Websocket和Zookeeper機(jī)制有點(diǎn)類似，將網(wǎng)關(guān)與admin建立好websocket連接時(shí)，admin會(huì)推送一次全量數(shù)據(jù)，后續(xù)如果配置數(shù)據(jù)發(fā)生變更，則將增量數(shù)據(jù)通過websocket主動(dòng)推送給soul-web。