[HUDI-708] Add temps show and unit test for TempViewCommand (#1770)

hudi-cli/src/main/java/org/apache/hudi/cli/HoodieCLI.java

@@ -115,4 +115,16 @@ public class HoodieCLI {
     return tempViewProvider;
   }
 
+  /**
+   * Close tempViewProvider.
+   * <p/>
+   * For test, avoid multiple SparkContexts.
+   */
+  public static synchronized void closeTempViewProvider() {
+    if (tempViewProvider != null) {
+      tempViewProvider.close();
+      tempViewProvider = null;
+    }
+  }
+
 }

hudi-cli/src/main/java/org/apache/hudi/cli/commands/TempViewCommand.java

@@ -20,36 +20,55 @@ package org.apache.hudi.cli.commands;
 
 import org.apache.hudi.cli.HoodieCLI;
 
+import org.apache.hudi.exception.HoodieException;
 import org.springframework.shell.core.CommandMarker;
 import org.springframework.shell.core.annotation.CliCommand;
 import org.springframework.shell.core.annotation.CliOption;
 import org.springframework.stereotype.Component;
 
-import java.io.IOException;
-
 /**
  * CLI command to query/delete temp views.
  */
 @Component
 public class TempViewCommand implements CommandMarker {
 
-  private static final String EMPTY_STRING = "";
+  public static final String QUERY_SUCCESS = "Query ran successfully!";
+  public static final String QUERY_FAIL = "Query ran failed!";
+  public static final String SHOW_SUCCESS = "Show all views name successfully!";
 
-  @CliCommand(value = "temp_query", help = "query against created temp view")
+  @CliCommand(value = {"temp_query", "temp query"}, help = "query against created temp view")
   public String query(
-          @CliOption(key = {"sql"}, mandatory = true, help = "select query to run against view") final String sql)
-          throws IOException {
+          @CliOption(key = {"sql"}, mandatory = true, help = "select query to run against view") final String sql) {
+
+    try {
+      HoodieCLI.getTempViewProvider().runQuery(sql);
+      return QUERY_SUCCESS;
+    } catch (HoodieException ex) {
+      return QUERY_FAIL;
+    }
 
-    HoodieCLI.getTempViewProvider().runQuery(sql);
-    return EMPTY_STRING;
   }
 
-  @CliCommand(value = "temp_delete", help = "Delete view name")
-  public String delete(
-          @CliOption(key = {"view"}, mandatory = true, help = "view name") final String tableName)
-          throws IOException {
+  @CliCommand(value = {"temps_show", "temps show"}, help = "Show all views name")
+  public String showAll() {
 
-    HoodieCLI.getTempViewProvider().deleteTable(tableName);
-    return EMPTY_STRING;
+    try {
+      HoodieCLI.getTempViewProvider().showAllViews();
+      return SHOW_SUCCESS;
+    } catch (HoodieException ex) {
+      return "Show all views name failed!";
+    }
+  }
+
+  @CliCommand(value = {"temp_delete", "temp delete"}, help = "Delete view name")
+  public String delete(
+          @CliOption(key = {"view"}, mandatory = true, help = "view name") final String tableName) {
+
+    try {
+      HoodieCLI.getTempViewProvider().deleteTable(tableName);
+      return String.format("Delete view %s successfully!", tableName);
+    } catch (HoodieException ex) {
+      return String.format("Delete view %s failed!", tableName);
+    }
   }
 }

hudi-cli/src/main/java/org/apache/hudi/cli/utils/SparkTempViewProvider.java

@@ -101,6 +101,17 @@ public class SparkTempViewProvider implements TempViewProvider {
     }
   }
 
+  @Override
+  public void showAllViews() {
+    try {
+      sqlContext.sql("SHOW TABLES").show(Integer.MAX_VALUE, false);
+    } catch (Throwable ex) {
+      // log full stack trace and rethrow. Without this its difficult to debug failures, if any
+      LOG.error("unable to get all views ", ex);
+      throw new HoodieException(ex);
+    }
+  }
+
   @Override
   public void deleteTable(String tableName) {
     try {
@@ -112,6 +123,13 @@ public class SparkTempViewProvider implements TempViewProvider {
     }
   }
 
+  @Override
+  public void close() {
+    if (sqlContext != null) {
+      sqlContext.sparkSession().stop();
+    }
+  }
+
   private DataType getDataType(Comparable comparable) {
     if (comparable instanceof Integer) {
       return DataTypes.IntegerType;

hudi-cli/src/main/java/org/apache/hudi/cli/utils/TempViewProvider.java

@@ -18,12 +18,17 @@
 
 package org.apache.hudi.cli.utils;
 
+import java.io.Closeable;
 import java.util.List;
 
-public interface TempViewProvider {
+public interface TempViewProvider extends Closeable {
   void createOrReplace(String tableName, List<String> headers, List<List<Comparable>> rows);
 
   void runQuery(String sqlText);
 
+  void showAllViews();
+
   void deleteTable(String tableName);
+
+  void close();
 }