Address Enis' review comments

Author: tedyu

hbase-server/src/main/java/org/apache/hadoop/hbase/mapreduce/WALPlayer.java

@@ -293,13 +293,11 @@ public Job createSubmittableJob(String[] args)
       // No reducers.
       job.setNumReduceTasks(0);
     }
-    String codecCls = WALCellCodec.getNonDefaultWALCellCodecClass(conf);
-    if (codecCls != null) {
-      try {
-        TableMapReduceUtil.addDependencyJars(conf, Class.forName(codecCls));
-      } catch (Exception e) {
-        throw new IOException("Cannot determine wal codec class " + codecCls, e);
-      }
+    String codecCls = WALCellCodec.getWALCellCodecClass(conf);
+    try {
+      TableMapReduceUtil.addDependencyJars(conf, Class.forName(codecCls));
+    } catch (Exception e) {
+      throw new IOException("Cannot determine wal codec class " + codecCls, e);
     }
     return job;
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/WALCellCodec.java

@@ -82,21 +82,10 @@ public WALCellCodec(Configuration conf, CompressionContext compression) {
     this.compression = compression;
   }
 
-  static String getWALCellCodecClass(Configuration conf) {
+  public static String getWALCellCodecClass(Configuration conf) {
     return conf.get(WAL_CELL_CODEC_CLASS_KEY, WALCellCodec.class.getName());
   }
 
-  /**
-   * Retrieves custom WAL codec class name
-   * @param conf the Configuration from which WAL codec class is to be retrieved
-   * @return name of custom WAL codec class. If default codec is specified, return null
-   */
-  public static String getNonDefaultWALCellCodecClass(Configuration conf) {
-    String defaultCodec = WALCellCodec.class.getName();
-    String codec = conf.get(WAL_CELL_CODEC_CLASS_KEY, defaultCodec);
-    return !defaultCodec.equals(codec) ? codec : null;
-  }
-
   /**
    * Create and setup a {@link WALCellCodec} from the {@code cellCodecClsName} and
    * CompressionContext, if {@code cellCodecClsName} is specified.