ENG-3059: Keep java client API to pass in number of tablets for redis…

… table creation.

Summary:
To keep a backward compatible client app that can be called from newer YW on older versions of YB.

Test Plan:
Jenkins: java only

Created universe from UI/YW using this local java client with older "0.9.6.0-b8" YB, and redis got created correctly.

Reviewers: bogdan

Reviewed By: bogdan

Subscribers: ybase

Differential Revision: https://phabricator.dev.yugabyte.com/D4405

java/yb-client/src/main/java/org/yb/client/YBClient.java

@@ -95,6 +95,40 @@ public YBClient(AsyncYBClient asyncClient) {
     this.asyncClient = asyncClient;
   }
 
+  /**
+   * Create redis table options object.
+   * @param numTablets number of pre-split tablets.
+   * @return an options object to be used during table creation.
+   */
+  public static CreateTableOptions getRedisTableOptions(int numTablets) {
+    CreateTableOptions cto = new CreateTableOptions();
+    if (numTablets <= 0) {
+      String msg = "Number of tablets " + numTablets + " cannot be less than one.";
+      LOG.error(msg);
+      throw new RuntimeException(msg);
+    }
+
+    cto.setTableType(TableType.REDIS_TABLE_TYPE)
+       .setNumTablets(numTablets);
+    return cto;
+  }
+
+  /**
+   * Create a redis table on the cluster with the specified name and tablet count.
+   * @param name Tables name
+   * @param numTablets number of pre-split tablets
+   * @return an object to communicate with the created table.
+   */
+  public YBTable createRedisTable(String name, int numTablets) throws Exception {
+    CreateKeyspaceResponse resp = this.createKeyspace(REDIS_KEYSPACE_NAME);
+    if (resp.hasError()) {
+      throw new RuntimeException("Could not create keyspace " + REDIS_KEYSPACE_NAME +
+                                 ". Error :" + resp.errorMessage());
+    }
+    return createTable(REDIS_KEYSPACE_NAME, name, getRedisSchema(),
+                       getRedisTableOptions(numTablets));
+  }
+
   /**
    * Create a redis table on the cluster with the specified name.
    * @param name Table name
@@ -103,8 +137,8 @@ public YBClient(AsyncYBClient asyncClient) {
   public YBTable createRedisTable(String name) throws Exception {
     CreateKeyspaceResponse resp = this.createKeyspace(REDIS_KEYSPACE_NAME);
     if (resp.hasError()) {
-      throw new RuntimeException("Could not create keyspace " + REDIS_KEYSPACE_NAME + ". Error :" +
-                                resp.errorMessage());
+      throw new RuntimeException("Could not create keyspace " + REDIS_KEYSPACE_NAME +
+                                 ". Error :" + resp.errorMessage());
     }
     return createTable(REDIS_KEYSPACE_NAME, name, getRedisSchema(),
                        new CreateTableOptions().setTableType(TableType.REDIS_TABLE_TYPE));