/**

 * <code>RecordWriter</code> writes the output &lt;key, value&gt; pairs

 * to an output file.

 * <p><code>RecordWriter</code> implementations write the job outputs to the

 * {@link FileSystem}.

 *

 * @see OutputFormat

 */

@InterfaceAudience.Public

@InterfaceStability.Stable

public abstract class RecordWriter<K, V> {

  /**

   * Writes a key/value pair.

   * 将Map/Reduce结果的key/value写到文件系统中去。

   * @param key the key to write.

   * @param value the value to write.

   * @throws IOException

   */

  public abstract void write(K key, V value) throws IOException, InterruptedException;

  /**

   * Close this <code>RecordWriter</code> to future operations.

   * 关闭输出操作

   * @param context the context of the task

   * @throws IOException

   */

  public abstract void close(TaskAttemptContext context)

          throws IOException, InterruptedException;

}