如何写代码

1.方法嵌套实现方法的重载：

public class EventBuilder {

  /**
   * Instantiate an Event instance based on the provided body and headers.
   * If <code>headers</code> is <code>null</code>, then it is ignored.
   * @param body
   * @param headers
   * @return
   */
  public static Event withBody(byte[] body, Map<String, String> headers) {
    Event event = new SimpleEvent();

    if(body == null) {
      body = new byte[0];
    }
    event.setBody(body);

    if (headers != null) {
      event.setHeaders(new HashMap<String, String>(headers));
    }

    return event;
  }

  public static Event withBody(byte[] body) {
    return withBody(body, null);
  }

  public static Event withBody(String body, Charset charset,
      Map<String, String> headers) {

    return withBody(body.getBytes(charset), headers);
  }

  public static Event withBody(String body, Charset charset) {
    return withBody(body, charset, null);
  }

}

2.序列器这种适合作为成员变量存在在读写类中，并不适合根据序列器定义不同读写类。

   这样reader、writer这种类的基本信息不至于反复定义，序列器只需要做序列文本的工作就可以了。

public class ReliableSpoolingFileEventReader implements ReliableEventReader {

  private static final Logger logger = LoggerFactory
      .getLogger(ReliableSpoolingFileEventReader.class);

  static final String metaFileName = ".flumespool-main.meta";

  private final File spoolDirectory;
  private final String completedSuffix;
  private final String deserializerType;
  private final Context deserializerContext;
  private final Pattern ignorePattern;
  private final File metaFile;
  private final boolean annotateFileName;
  private final boolean annotateBaseName;
  private final String fileNameHeader;
  private final String baseNameHeader;
  private final String deletePolicy;
  private final Charset inputCharset;
  private final DecodeErrorPolicy decodeErrorPolicy;
  private final ConsumeOrder consumeOrder; 
  private EventDeserializer des = currentFile.get().getDeserializer();
}

3.