import com.netflix.config.PolledConfigurationSource; //导入依赖的package包/类
@Override
	public PropertySource<?> locate(Environment environment) {
		
		try {
			// configuration from local properties file
			ConcurrentMapConfiguration configFromPropertiesFile = new ConcurrentMapConfiguration(new PropertiesConfiguration("application.yml"));
			
			// configuration from system properties
			ConcurrentMapConfiguration configFromSystemProperties = new ConcurrentMapConfiguration(new SystemConfiguration());
			
			// configuration from a dynamic source
//			PolledConfigurationSource source = new NetflixUrlPolledConfigurationSource();
			PolledConfigurationSource source = new NetflixEurekaPolledConfigurationSource();
			AbstractPollingScheduler scheduler = new FixedDelayPollingScheduler();
			DynamicConfiguration dynamicConfiguration = new DynamicConfiguration(source, scheduler);
			
			// create a hierarchy of configuration that makes
			// 1) dynamic configuration source override system properties
			// 2) system properties override properties file
			ConcurrentCompositeConfiguration finalConfig = new ConcurrentCompositeConfiguration();
			finalConfig.addConfiguration(dynamicConfiguration, "dynamicConfig");
			finalConfig.addConfiguration(configFromSystemProperties, "systemConfig");
			finalConfig.addConfiguration(configFromPropertiesFile, "fileConfig");
			
			// install with ConfigurationManager so that finalConfig
			// becomes the source of dynamic properties
			ConfigurationManager.install(finalConfig);
		} catch(Exception e) {
			logger.error(e.getMessage());
		}
		
		return null;
	}
 

import com.netflix.config.PolledConfigurationSource; //导入依赖的package包/类
@Override
protected synchronized void initialLoad(PolledConfigurationSource source, Configuration config) {
    try {
        super.initialLoad(source, config);
    } catch (Exception err) {
        LOGGER.warn("Initial dynamic configuration load failed", err);
    }
}
 

import com.netflix.config.PolledConfigurationSource; //导入依赖的package包/类
public NamedDynamicConfiguration(PolledConfigurationSource source, AbstractPollingScheduler scheduler, String sourceName) {
    super(source, scheduler);
    this.sourceName = sourceName;
}
 

import com.netflix.config.PolledConfigurationSource; //导入依赖的package包/类
public NamedDynamicConfiguration(PolledConfigurationSource source, AbstractPollingScheduler scheduler) {
    super(source, scheduler);
}