携程 Apollo 配置中心：Example

    <dependency>
        <groupId>com.ctrip.framework.apollo</groupId>
        <artifactId>apollo-client</artifactId>
        <version>1.3.0</version>
    </dependency>

# appid 是应用的身份信息，需后台设定
app:
  id: 2019
# 一般指向 config service 服务地址
apollo:
  meta: http://localhost:8080

@EnableApolloConfig
@SpringBootApplication
public class ApolloApplication {

    public static void main(String[] args) {
        SpringApplication.run(ApolloApplication.class, args);
        System.out.println("ApolloApplication started...");

        // 监听配置变化事件
        Config config = ConfigService.getAppConfig();
        config.addChangeListener(changeEvent -> {
            log.debug("Changes for namespace {}", changeEvent.getNamespace());
            for (String key : changeEvent.changedKeys()) {
                ConfigChange change = changeEvent.getChange(key);
                System.out.println(String.format("Found change - key: %s, oldValue: %s, newValue: %s, changeType: %s",
                        change.getPropertyName(), change.getOldValue(), change.getNewValue(), change.getChangeType()));
            }
        });
    }

}

logging:
  level:
    cn.mariojd.config.apollo: info

@Slf4j
@Configuration
public class DynamicLogLevelConfig {

    @Resource
    private LoggingSystem loggingSystem;

    private static final String LOG_KEY = "logging.level";

    @ApolloConfigChangeListener
    private void configChangeListener(ConfigChangeEvent e) {
        e.changedKeys().stream().filter(key -> StringUtils.startsWithIgnoreCase(LOG_KEY, key)).forEach(key -> {
            ConfigChange change = e.getChange(key);
            String oleLevel = change.getOldValue();
            String newLevel = change.getNewValue();

            // 只有合法的日志等级配置才会生效，常见的如 DEBUG, INFO, WARN, ERROR
            Arrays.stream(LogLevel.values()).filter(logLevel ->
                    StringUtils.startsWithIgnoreCase(newLevel, logLevel.toString())).findFirst()
                    .ifPresent(logLevel -> loggingSystem.setLogLevel("cn.mariojd.config.apollo", logLevel));

            System.out.println(String.format("动态调整日志级别：Key -> %s ; OldLevel -> %s ; NewLevel -> %s",
                    key, oleLevel, newLevel));
        });
    }

}

@Slf4j
@EnableApolloConfig
@SpringBootApplication
public class ApolloApplication implements InitializingBean {

    private ExecutorService executorService = Executors.newFixedThreadPool(1);

    public static void main(String[] args) {
        SpringApplication.run(ApolloApplication.class, args);
        log.info("ApolloApplication started...");
    }

    @Override
    public void afterPropertiesSet() {
        executorService.submit(this::testDynamicLogLevelConfig);
    }

    public void testDynamicLogLevelConfig() {
        // 默认 INFO 级别下程序不输出 DEBUG 日志
        for (; ; ) {
            log.debug("Debug log...");
            log.info("Info log...");
            log.warn("Warn log...");
            log.error("Error log...");
            try {
                TimeUnit.SECONDS.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }