Connect to Managed ClickHouse® with Java

Learn how to connect to your Managed ClickHouse® service with Java using the ClickHouse JDBC driver and the HTTPS port.

Prerequisites

• Java 8 or later
• ClickHouse JDBC driver

Identify connection information

To run the code for connecting to your service, first identify values of the following variables:

Read the host and the port from the clickhouse_https entry of the service components. Ports are assigned per service, so read them from your own service rather than reusing a value from an example:

exo x get-dbaas-service-clickhouse my-clickhouse -z ch-gva-2 \
  -q "components[?component=='clickhouse_https']"

Rather than hard-coding the password in your source, read it into an environment variable. The --raw flag returns the bare value, without JSON quotes or a trailing newline:

export CH_PASS=$(exo x reveal-dbaas-clickhouse-user-password my-clickhouse avnadmin \
  -z ch-gva-2 -q 'password' --raw)

Connect to the service

1. Add the ClickHouse JDBC driver to your Maven dependencies.

   <dependency>
       <groupId>com.clickhouse</groupId>
       <artifactId>clickhouse-jdbc</artifactId>
       <version>0.3.2-patch11</version>
       <classifier>all</classifier>
       <exclusions>
           <exclusion>
               <groupId>*</groupId>
               <artifactId>*</artifactId>
           </exclusion>
       </exclusions>
   </dependency>

2. Build the JDBC connection string, replacing CLICKHOUSE_HTTPS_HOST and CLICKHOUSE_HTTPS_PORT with the host and port of the clickhouse_https component of your service. You use this string in the code below.

   jdbc:ch://CLICKHOUSE_HTTPS_HOST:CLICKHOUSE_HTTPS_PORT?ssl=true

3. Replace CLICKHOUSE_USER in the code with the user of your service, then run the code. The password is read from the CH_PASS environment variable exported above, so it stays out of your source and out of your shell history.

   import com.clickhouse.jdbc.ClickHouseConnection;
   import com.clickhouse.jdbc.ClickHouseDataSource;
   
   import java.sql.ResultSet;
   import java.sql.SQLException;
   import java.sql.Statement;
   
   public class Main {
       public static void main(String[] args) throws SQLException {
           String connString = "jdbc:ch://CLICKHOUSE_HTTPS_HOST:CLICKHOUSE_HTTPS_PORT?ssl=true&sslmode=STRICT";
           ClickHouseDataSource database = new ClickHouseDataSource(connString);
           ClickHouseConnection connection = database.getConnection("CLICKHOUSE_USER", System.getenv("CH_PASS"));
           Statement statement = connection.createStatement();
           ResultSet result_set = statement.executeQuery("SELECT 1 AS one");
           while (result_set.next()) {
               System.out.println(result_set.getInt("one"));
           }
       }
   }

Now you have your service connection set up and you can proceed to uploading data into your database.

For information on how to connect to the Managed ClickHouse service with the ClickHouse client, see Connect with the ClickHouse client.