flume-event类
/*Basic representation of a data object in Flume.
Provides access to data as it flows through the system.
Flume中数据对象的基本表示。
提供对数据流经系统的访问
*/
public interface Event {
/**
* Returns a map of name-value pairs describing the data stored in the body.
返回描述存储在正文中的数据的名称 - 值对的映射
*/
public Map<String, String> getHeaders();