import com.ctrip.framework.apollo.enums.PropertyChangeType;
import com.ctrip.framework.apollo.model.ConfigChange;
import com.ctrip.framework.apollo.model.ConfigChangeEvent;
import com.ctrip.framework.apollo.spring.annotation.ApolloConfigChangeListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
import org.springframework.cloud.gateway.config.GatewayProperties;
import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
import java.util.ArrayList;
/**
 * @author ksewen
 * @date 2019/5/175:24 PM
 */
@Configuration
public class GatewayPropertiesRefresher implements ApplicationContextAware,ApplicationEventPublisherAware {
    private static final Logger logger = LoggerFactory.getLogger(GatewayPropertiesRefresher.class);
    private static final String ID_PATTERN = "spring\\.cloud\\.gateway\\.routes\\[\\d+\\]\\.id";
    private static final String DEFAULT_FILTER_PATTERN = "spring\\.cloud\\.gateway\\.default-filters\\[\\d+\\]\\.name";
    private ApplicationContext applicationContext;
    private ApplicationEventPublisher publisher;
    @Autowired
    private GatewayProperties gatewayProperties;
    @Autowired
    private RouteDefinitionWriter routeDefinitionWriter;
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        this.publisher = applicationEventPublisher;
    }
    @ApolloConfigChangeListener(interestedKeyPrefixes = "spring.cloud.gateway.",value="recommend-facade.yml")
    public void onChange(ConfigChangeEvent changeEvent) {
        refreshGatewayProperties(changeEvent);
    }
    /***
     * 刷新org.springframework.cloud.gateway.config.PropertiesRouteDefinitionLocator中定義的routes
     *
     * @param changeEvent
     * @return void
     * @author ksewen
     * @date 2019/5/21 2:13 PM
     */
    private void refreshGatewayProperties(ConfigChangeEvent changeEvent) {
        logger.info("Refreshing GatewayProperties!");
        preDestroyGatewayProperties(changeEvent);
        this.applicationContext.publishEvent(new EnvironmentChangeEvent(changeEvent.changedKeys()));
        refreshGatewayRouteDefinition();
        logger.info("GatewayProperties refreshed!");
    }
    /***
     * GatewayProperties沒有@PreDestroy和destroy方法
     * org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder#rebind(java.lang.String)中destroyBean時(shí)不會(huì)銷毀當(dāng)前對(duì)象
     * 如果把spring.cloud.gateway.前綴的配置項(xiàng)全部刪除（例如需要?jiǎng)討B(tài)刪除最后一個(gè)路由的場(chǎng)景），initializeBean時(shí)也無法創(chuàng)建新的bean，則return當(dāng)前bean
     * 若仍保留有spring.cloud.gateway.routes[n]或spring.cloud.gateway.default-filters[n]等配置，initializeBean時(shí)會(huì)注入新的屬性替換已有的bean
     * 這個(gè)方法提供了類似@PreDestroy的操作，根據(jù)配置文件的實(shí)際情況把org.springframework.cloud.gateway.config.GatewayProperties#routes
     * 和org.springframework.cloud.gateway.config.GatewayProperties#defaultFilters兩個(gè)集合清空
     *
     * @param
     * @return void
     * @author ksewen
     * @date 2019/5/21 2:13 PM
     */
    private synchronized void preDestroyGatewayProperties(ConfigChangeEvent changeEvent) {
        logger.info("Pre Destroy GatewayProperties!");
        final boolean needClearRoutes = this.checkNeedClear(changeEvent, ID_PATTERN, this.gatewayProperties.getRoutes().size());
        if (needClearRoutes) {
            this.gatewayProperties.setRoutes(new ArrayList<>());
        }
        final boolean needClearDefaultFilters = this.checkNeedClear(changeEvent, DEFAULT_FILTER_PATTERN, this.gatewayProperties.getDefaultFilters().size());
        if (needClearDefaultFilters) {
            this.gatewayProperties.setRoutes(new ArrayList<>());
        }
        logger.info("Pre Destroy GatewayProperties finished!");
    }
    private void refreshGatewayRouteDefinition() {
        logger.info("Refreshing Gateway RouteDefinition!");
        this.publisher.publishEvent(new RefreshRoutesEvent(this));
        logger.info("Gateway RouteDefinition refreshed!");
    }
    /***
     * 根據(jù)changeEvent和定義的pattern匹配key，如果所有對(duì)應(yīng)PropertyChangeType為DELETED則需要清空GatewayProperties里相關(guān)集合
     *
     * @param changeEvent
     * @param pattern
     * @param existSize
     * @return boolean
     * @author ksewen
     * @date 2019/5/23 2:18 PM
     */
    private boolean checkNeedClear(ConfigChangeEvent changeEvent, String pattern, int existSize) {
        return changeEvent.changedKeys().stream().filter(key -> key.matches(pattern))
                .filter(key -> {
                    ConfigChange change = changeEvent.getChange(key);
                    return PropertyChangeType.DELETED.equals(change.getChangeType());
                }).count() == existSize;
    }
}

    @ApolloConfigChangeListener(interestedKeyPrefixes = "spring.cloud.gateway.",value="xxxx.yml")
    public void onChange(ConfigChangeEvent changeEvent) {
        refreshGatewayProperties(changeEvent);
    }

env=DEV

eureka.client.service-url.defaultZone	http://【apollo所在的ip】:8080/eureka