[docs] Clean up completeness checker for configuration docs.

flink-core/src/main/java/org/apache/flink/configuration/ConfigConstants.java

@@ -18,13 +18,6 @@
 
 package org.apache.flink.configuration;
 
-import org.apache.commons.io.FileUtils;
-import org.apache.flink.util.StringUtils;
-
-import java.io.File;
-import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
-
 /**
  * This class contains all constants for the configuration. That includes the configuration keys and
  * the default values.
@@ -751,25 +744,4 @@ public final class ConfigConstants {
 	 * Not instantiable.
 	 */
 	private ConfigConstants() {}
-
-
-	/**
-	 * Config constants completeness checker utility
-	 */
-	public static void main(String[] args) throws Exception {
-		String configFileContents = FileUtils.readFileToString(new File("docs/setup/config.md"));
-		Field[] fields = ConfigConstants.class.getFields();
-		for(Field field : fields) {
-			if(Modifier.isStatic(field.getModifiers()) && field.getType().equals(String.class) && !field.getName().startsWith("DEFAULT")) {
-
-
-				Object val = field.get(ConfigConstants.class);
-
-				System.out.println("Found static field "+field+" = "+val);
-				if(!configFileContents.contains((String)val)) {
-					System.out.println("++++ "+val+" is not mentioned in the configuration file!!!");
-				}
-			}
-		}
-	}
 }

flink-core/src/test/java/org/apache/flink/configuration/ConfigDocsCompletenessChecker.java

@@ -0,0 +1,49 @@
+/*
+ * 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.flink.configuration;
+
+import org.apache.commons.io.FileUtils;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+/**
+ * A small utility that collects all config keys that are not described in
+ * the configuration reference documentation.
+ */
+public class ConfigDocsCompletenessChecker {
+
+	public static void main(String[] args) throws Exception {
+
+		String configFileContents = FileUtils.readFileToString(new File("docs/setup/config.md"));
+		Field[] fields = ConfigConstants.class.getFields();
+
+		for (Field field : fields) {
+			if (Modifier.isStatic(field.getModifiers()) && field.getType().equals(String.class) &&
+					!field.getName().startsWith("DEFAULT"))
+			{
+				Object val = field.get(null);
+				if (!configFileContents.contains((String)val)) {
+					System.out.println("++++ "+val+" is not mentioned in the configuration file!!!");
+				}
+			}
+		}
+	}
+}