apollo-core/src/main/java/com/ctrip/framework/foundation/internals/NetworkInterfaceManager.java/NetworkInterfaceManager/getProperty
class NetworkInterfaceManager:  private String getProperty(String name) {
    String value = null;

    value = System.getProperty(name);

    if (value == null) {
      value = System.getenv(name);
    }

    return value;
  }