Connect to Redis Data in JRuby

JRuby is a high-performance, stable, fully threaded Java implementation of the Ruby programming language. The CData JDBC Driver for Redis makes it easy to integrate connectivity to live Redis data in JRuby. This article shows how to create a simple JRuby app that connects to Redis data, executes a query, and displays the results.

Configure a JDBC Connection to Redis Data

Before creating the app, note the installation location for the JAR file for the JDBC Driver (typically C:\Program Files\CData\CData JDBC Driver for Redis\lib).

JRuby natively supports JDBC, so you can easily connect to Redis and execute SQL queries. Initialize the JDBC connection with the getConnection function of the java.sql.DriverManager class.

Set the following connection properties to connect to a Redis instance:

• : Set this to the name or address of the server your Redis instance is running on. You can specify the port in .
• : Set this to the password used to authenticate with a password-protected Redis instance , using the Redis AUTH command.

Set to negotiate SSL/TLS encryption when you connect.

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the Redis JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

java -jar cdata.jdbc.redis.jar

Fill in the connection properties and copy the connection string to the clipboard.

Below is a typical JDBC connection string for Redis:

jdbc:redis:Server=127.0.0.1;Port=6379;Password=myPassword;

Create a JRuby App with Connectivity to Redis Data

Create a new Ruby file (for example: RedisSelect.rb) and open it in a text editor. Copy the following code into your file:

require 'java'
require 'rubygems'
require 'C:/Program Files/CData/CData JDBC Driver for Redis 2018/lib/cdata.jdbc.redis.jar'

url = "jdbc:redis:Server=127.0.0.1;Port=6379;Password=myPassword;"
conn = java.sql.DriverManager.getConnection(url)
stmt = conn.createStatement
rs = stmt.executeQuery("SELECT City, CompanyName FROM Customers")
while (rs.next) do
 puts rs.getString(1) + ' ' + rs.getString(2)
end

With the file completed, you are ready to display your Redis data with JRuby. To do so, simply run your file from the command line:

jruby -S RedisSelect.rb

Writing SQL-92 queries to Redis allows you to quickly and easily incorporate Redis data into your own JRuby applications. Download a free trial today!