Connect an application

YugabyteDB JDBC Smart Driver is a JDBC driver for YSQL built on the PostgreSQL JDBC driver, with additional connection load balancing features.

For Java applications, the JDBC driver provides database connectivity through the standard JDBC application program interface (APIs) available on the Java platform.

YugabyteDB Managed

To use smart driver load balancing features when connecting to clusters in YugabyteDB Managed, applications must be deployed in a VPC that has been peered with the cluster VPC. For applications that access the cluster from outside the VPC network, use the upstream PostgreSQL driver instead; in this case, the cluster performs the load balancing. Applications that use smart drivers from outside the VPC network fall back to the upstream driver behaviour automatically. For more information, refer to Using smart drivers with YugabyteDB Managed.

CRUD operations

The following sections demonstrate how to perform common tasks required for Java application development.

To start building your application, make sure you have met the prerequisites.

Step 1: Set up the client dependencies

Maven dependency

If you are using Maven, add the following to your pom.xml of your project.

<dependency>
  <groupId>com.yugabyte</groupId>
  <artifactId>jdbc-yugabytedb</artifactId>
  <version>42.3.0</version>
</dependency>

<!-- https://mvnrepository.com/artifact/com.zaxxer/HikariCP -->
<dependency>
  <groupId>com.zaxxer</groupId>
  <artifactId>HikariCP</artifactId>
  <version>4.0.3</version>
</dependency>

Install the added dependency using mvn install.

Gradle dependency

If you are using Gradle, add the following dependencies to your build.gradle file:

implementation 'com.yugabyte:jdbc-yugabytedb:42.3.0'
implementation 'com.zaxxer:HikariCP:4.0.3'

Step 2: Set up the database connection

After setting up the dependencies, implement the Java client application using the YugabyteDB JDBC driver to connect to your YugabyteDB cluster and run queries on the sample data.

Set up the driver properties to configure the credentials and SSL certificates for connecting to your cluster. Java applications can connect to and query the YugabyteDB database using the java.sql.DriverManager class. All the JDBC interfaces required for working with YugabyteDB database are part of the java.sql.* package.

Use the DriverManager.getConnection method to obtain the connection object for the YugabyteDB database, which can then be used to perform DDL and DML operations against the database.

The following table describes the connection parameters required to connect, including smart driver parameters for uniform and topology load balancing.

JDBC Parameter Description Default
hostname Host name of the YugabyteDB instance. You can also enter multiple addresses. localhost
port Listen port for YSQL 5433
database Database name yugabyte
user User connecting to the database yugabyte
password User password yugabyte
load-balance Uniform load balancing Defaults to upstream driver behavior unless set to 'true'
yb-servers-refresh-interval If load_balance is true, the interval in seconds to refresh the servers list 300
topology-keys Topology-aware load balancing If load-balance is true, uses uniform load balancing unless set to comma-separated geo-locations in the form cloud.region.zone.

The following is an example JDBC URL for connecting to YugabyteDB:

jdbc:yugabytedb://hostname:port/database?user=yugabyte&password=yugabyte&load-balance=true& \
    yb-servers-refresh-interval=240& \
    topology-keys=cloud.region.zone1,cloud.region.zone2

After the driver establishes the initial connection, it fetches the list of available servers from the cluster, and load-balances subsequent connection requests across these servers.

Use multiple addresses

You can specify multiple hosts in the connection string to provide alternative options during the initial connection in case the primary address fails.

Tip

To obtain a list of available hosts, you can connect to any cluster node and use the yb_servers() YSQL function.

Delimit the addresses using commas, as follows:

jdbc:yugabytedb://hostname1:port,hostname2:port,hostname3:port/database?user=yugabyte&password=yugabyte&load-balance=true& \
    topology-keys=cloud.region.zone1,cloud.region.zone2

The hosts are only used during the initial connection attempt. If the first host is down when the driver is connecting, the driver attempts to connect to the next host in the string, and so on.

Use SSL

The following table describes the connection parameters required to connect using SSL.

JDBC Parameter Description Default
ssl Enable SSL client connection false
sslmode SSL mode require
sslrootcert Path to the root certificate on your computer ~/.postgresql/
sslhostnameverifier Address of host name verifier; only used for YugabyteDB Managed clusters where sslmode is verify-full. Driver v42.3.5-yb-2 and later only. com.yugabyte.ysql.YBManagedHostnameVerifier

The following is an example JDBC URL for connecting to a YugabyteDB cluster with SSL encryption enabled.

jdbc:yugabytedb://hostname:port/database?user=yugabyte&password=yugabyte&load-balance=true& \
    ssl=true&sslmode=verify-full&sslrootcert=~/.postgresql/root.crt

If you created a cluster on YugabyteDB Managed, use the cluster credentials and download the SSL Root certificate.

To use load balancing and SSL mode verify-full with a cluster in YugabyteDB Managed, you need to provide the additional sslhostnameverifier parameter, set to com.yugabyte.ysql.YBManagedHostnameVerifier. (Available in driver version 42.3.5-yb-2 or later. For previous versions of the driver, use verify-ca.)

Step 3: Write your application

Create a new Java class called QuickStartApp.java in the base package directory of your project as follows:

touch ./src/main/java/com/yugabyte/QuickStartApp.java

Copy the following code to set up a YugabyteDB table and query the table contents from the Java client. Be sure to replace the connection string yburl with credentials of your cluster and SSL certificate if required.

package com.yugabyte;

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;

public class QuickStartApp {
  public static void main(String[] args) throws ClassNotFoundException, SQLException {
    Class.forName("com.yugabyte.Driver");
    String yburl = "jdbc:yugabytedb://127.0.0.1:5433/yugabyte?user=yugabyte&password=yugabyte&load-balance=true";
    Connection conn = DriverManager.getConnection(yburl);
    Statement stmt = conn.createStatement();
    try {
        System.out.println("Connected to the YugabyteDB Cluster successfully.");
        stmt.execute("DROP TABLE IF EXISTS employee");
        stmt.execute("CREATE TABLE IF NOT EXISTS employee" +
                    "  (id int primary key, name varchar, age int, language text)");
        System.out.println("Created table employee");

        String insertStr = "INSERT INTO employee VALUES (1, 'John', 35, 'Java')";
        stmt.execute(insertStr);
        System.out.println("EXEC: " + insertStr);

        ResultSet rs = stmt.executeQuery("select * from employee");
        while (rs.next()) {
          System.out.println(String.format("Query returned: name = %s, age = %s, language = %s",
                                          rs.getString(2), rs.getString(3), rs.getString(4)));
        }
    } catch (SQLException e) {
      System.err.println(e.getMessage());
    }
  }
}

Run the application

Run the project QuickStartApp.java using the following command:

mvn -q package exec:java -DskipTests -Dexec.mainClass=com.yugabyte.QuickStartApp

You should see output similar to the following:

Connected to the YugabyteDB Cluster successfully.
Created table employee
Inserted data: INSERT INTO employee (id, name, age, language) VALUES (1, 'John', 35, 'Java');
Query returned: name=John, age=35, language: Java

If you receive no output or an error, check the parameters in the connection string.

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