SQL Workbench/J is a free, DBMS-independent, cross-platform SQL query tool.
Add the Elasticsearch JDBC driver to SQL Workbench/J through Manage Drivers either from the main windows in the File menu or from the Connect window:
Add a new entry to the list through the blank page button in the upper left corner. Add the JDBC jar, provide a name and click on the magnifier button to have the driver Classname picked-up automatically:
With the driver configured, create a new connection profile through File > Connect Window (or Alt+C shortcut):
Select the previously configured driver and set the URL of your cluster using the JDBC syntax. Verify the connection through the Test button - a confirmation window should appear that everything is properly configured.
The setup is complete.
SQL Workbench/J is ready to talk to Elasticsearch through SQL: click on the profile created to execute statements or explore the data: