HADOOP-11418. Property "io.compression.codec.lzo.class" does not work with other value besides default. (Yuanbo Liu via iwasakims)

(cherry picked from commit bec5b4cd8c)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/file/tfile/Compression.java

@@ -82,9 +82,9 @@ final class Compression {
       public synchronized boolean isSupported() {
         if (!checked) {
           checked = true;
-          String extClazz =
+          String extClazzConf = conf.get(CONF_LZO_CLASS);
-              (conf.get(CONF_LZO_CLASS) == null ? System
+          String extClazz = (extClazzConf != null) ?
-                  .getProperty(CONF_LZO_CLASS) : null);
+              extClazzConf : System.getProperty(CONF_LZO_CLASS);
           String clazz = (extClazz != null) ? extClazz : defaultClazz;
           try {
             LOG.info("Trying to load Lzo codec class: " + clazz);

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/file/tfile/TestCompression.java

@@ -0,0 +1,41 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.io.file.tfile;
+
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+
+public class TestCompression {
+
+  /**
+   * Regression test for HADOOP-11418.
+   * Verify we can set a LZO codec different from default LZO codec.
+   */
+  @Test
+  public void testConfigureLZOCodec() throws IOException {
+    // Dummy codec
+    String defaultCodec = "org.apache.hadoop.io.compress.DefaultCodec";
+    Compression.Algorithm.conf.set(
+        Compression.Algorithm.CONF_LZO_CLASS, defaultCodec);
+    assertEquals(defaultCodec,
+        Compression.Algorithm.LZO.getCodec().getClass().getName());
+  }
+}