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Get the Report →Connect to Presto Data in JRuby
Create a simple JRuby app with access to live Presto data.
JRuby is a high-performance, stable, fully threaded Java implementation of the Ruby programming language. The CData JDBC Driver for Presto makes it easy to integrate connectivity to live Presto data in JRuby. This article shows how to create a simple JRuby app that connects to Presto data, executes a query, and displays the results.
Configure a JDBC Connection to Presto 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 Presto\lib).
JRuby natively supports JDBC, so you can easily connect to Presto and execute SQL queries. Initialize the JDBC connection with the getConnection function of the java.sql.DriverManager class.
Set the Server and Port connection properties to connect, in addition to any authentication properties that may be required.
To enable TLS/SSL, set UseSSL to true.
Authenticating with LDAP
In order to authenticate with LDAP, set the following connection properties:
- AuthScheme: Set this to LDAP.
- User: The username being authenticated with in LDAP.
- Password: The password associated with the User you are authenticating against LDAP with.
Authenticating with Kerberos
In order to authenticate with KERBEROS, set the following connection properties:
- AuthScheme: Set this to KERBEROS.
- KerberosKDC: The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
- KerberosRealm: The Kerberos Realm used to authenticate the user with.
- KerberosSPN: The Service Principal Name for the Kerberos Domain Controller.
- KerberosKeytabFile: The Keytab file containing your pairs of Kerberos principals and encrypted keys.
- User: The user who is authenticating to Kerberos.
- Password: The password used to authenticate to Kerberos.
Built-in Connection String Designer
For assistance in constructing the JDBC URL, use the connection string designer built into the Presto JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.
java -jar cdata.jdbc.presto.jar
Fill in the connection properties and copy the connection string to the clipboard.
Below is a typical JDBC connection string for Presto:
jdbc:presto:Server=127.0.0.1;Port=8080;
Create a JRuby App with Connectivity to Presto Data
Create a new Ruby file (for example: PrestoSelect.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 Presto 2018/lib/cdata.jdbc.presto.jar'
url = "jdbc:presto:Server=127.0.0.1;Port=8080;"
conn = java.sql.DriverManager.getConnection(url)
stmt = conn.createStatement
rs = stmt.executeQuery("SELECT FirstName, LastName FROM Customer")
while (rs.next) do
puts rs.getString(1) + ' ' + rs.getString(2)
end
With the file completed, you are ready to display your Presto data with JRuby. To do so, simply run your file from the command line:
jruby -S PrestoSelect.rb
Writing SQL-92 queries to Presto allows you to quickly and easily incorporate Presto data into your own JRuby applications. Download a free trial today!