[ZEPPELIN-6451] Add default NotebookRepo settings methods to remove duplicated placeholder implementations

zeppelin-plugins/notebookrepo/azure/src/main/java/org/apache/zeppelin/notebook/repo/AzureNotebookRepo.java

@@ -28,9 +28,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URISyntaxException;
-import java.util.Collections;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
@@ -175,15 +173,4 @@ public void remove(String folderPath, AuthenticationInfo subject) {
   public void close() {
   }
 
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-  }
-
 }

zeppelin-plugins/notebookrepo/filesystem/src/main/java/org/apache/zeppelin/notebook/repo/FileSystemNotebookRepo.java

@@ -28,7 +28,6 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -132,15 +131,4 @@ public void close() {
     LOGGER.warn("close is not implemented for FileSystemNotebookRepo");
   }
 
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    LOGGER.warn("getSettings is not implemented for FileSystemNotebookRepo");
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-    LOGGER.warn("updateSettings is not implemented for FileSystemNotebookRepo");
-  }
-
 }

zeppelin-plugins/notebookrepo/gcs/src/main/java/org/apache/zeppelin/notebook/repo/GCSNotebookRepo.java

@@ -34,7 +34,6 @@
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -304,14 +303,4 @@ public void close() {
     //no-op
   }
 
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    LOGGER.warn("getSettings is not implemented for GCSNotebookRepo");
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-    LOGGER.warn("updateSettings is not implemented for GCSNotebookRepo");
-  }
 }

zeppelin-plugins/notebookrepo/mongo/src/main/java/org/apache/zeppelin/notebook/repo/MongoNotebookRepo.java

@@ -332,17 +332,6 @@ public void close() {
     client.close();
   }
 
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-  }
-
   /**
    * create until parent folder if not exists.
    *

zeppelin-plugins/notebookrepo/oss/src/main/java/org/apache/zeppelin/notebook/repo/OSSNotebookRepo.java

@@ -184,18 +184,6 @@ public void close() {
     ossOperator.shutdown();
   }
 
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-  }
-
-
   private static String buildRevisionsDirName(String noteId, String notePath) throws IOException {
     if (!notePath.startsWith("/")) {
       throw new IOException("Invalid notePath: " + notePath);

zeppelin-plugins/notebookrepo/s3/src/main/java/org/apache/zeppelin/notebook/repo/S3NotebookRepo.java

@@ -23,9 +23,7 @@
 import java.io.InputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
-import java.util.Collections;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 import org.apache.commons.io.FileUtils;
@@ -324,15 +322,4 @@ public void close() {
       s3client.shutdown();
     }
   }
-
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-    LOGGER.warn("Method not implemented");
-  }
 }

zeppelin-server/src/main/java/org/apache/zeppelin/notebook/repo/InMemoryNotebookRepo.java

@@ -25,9 +25,7 @@
 import org.apache.zeppelin.user.AuthenticationInfo;
 
 import java.io.IOException;
-import java.util.Collections;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 public class InMemoryNotebookRepo extends AbstractNotebookRepo {
@@ -107,16 +105,6 @@ public void close() {
 
   }
 
-  @Override
-  public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-    return Collections.emptyList();
-  }
-
-  @Override
-  public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-
-  }
-
   public void reset() {
     this.notes.clear();
   }

zeppelin-server/src/main/java/org/apache/zeppelin/notebook/repo/NotebookRepo.java

@@ -23,9 +23,11 @@
 import org.apache.zeppelin.notebook.NoteParser;
 import org.apache.zeppelin.notebook.NoteInfo;
 import org.apache.zeppelin.user.AuthenticationInfo;
+import org.slf4j.LoggerFactory;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
@@ -125,20 +127,33 @@ void move(String folderPath, String newFolderPath,
   /**
    * Get NotebookRepo settings got the given user.
    *
+   * Implementations that don't expose any configurable setting can rely on this default,
+   * which reports that the repo has no settings.
+   *
    * @param subject
    * @return
    */
   @ZeppelinApi
-  List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject);
+  default List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
+    LoggerFactory.getLogger(getClass())
+        .debug("getSettings is not implemented for {}", getClass().getSimpleName());
+    return Collections.emptyList();
+  }
 
   /**
    * update notebook repo settings.
    *
+   * Implementations that don't expose any configurable setting can rely on this default,
+   * which ignores the update and warns about it.
+   *
    * @param settings
    * @param subject
    */
   @ZeppelinApi
-  void updateSettings(Map<String, String> settings, AuthenticationInfo subject);
+  default void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
+    LoggerFactory.getLogger(getClass())
+        .warn("updateSettings is not implemented for {}", getClass().getSimpleName());
+  }
 
   NoteParser getNoteParser();
 

zeppelin-server/src/test/java/org/apache/zeppelin/notebook/NotebookTest.java

@@ -31,7 +31,6 @@
 import org.apache.zeppelin.interpreter.InterpreterSetting;
 import org.apache.zeppelin.interpreter.remote.RemoteInterpreter;
 import org.apache.zeppelin.notebook.repo.NotebookRepo;
-import org.apache.zeppelin.notebook.repo.NotebookRepoSettingsInfo;
 import org.apache.zeppelin.notebook.repo.NotebookRepoWithVersionControl;
 import org.apache.zeppelin.notebook.repo.VFSNotebookRepo;
 import org.apache.zeppelin.notebook.scheduler.QuartzSchedulerService;
@@ -61,7 +60,6 @@
 import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -190,16 +188,6 @@ public void close() {
 
     }
 
-    @Override
-    public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-      return Collections.emptyList();
-    }
-
-    @Override
-    public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-
-    }
-
     @Override
     public NoteParser getNoteParser() {
       return null;
@@ -276,16 +264,6 @@ public void close() {
 
     }
 
-    @Override
-    public List<NotebookRepoSettingsInfo> getSettings(AuthenticationInfo subject) {
-      return Collections.emptyList();
-    }
-
-    @Override
-    public void updateSettings(Map<String, String> settings, AuthenticationInfo subject) {
-
-    }
-
     @Override
     public NoteParser getNoteParser() {
       return null;