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Build a Java App with CockroachDB
Learn how to use CockroachDB from a simple Java application with the Hibernate ORM.
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This tutorial shows you how build a simple Java application with CockroachDB using a PostgreSQL-compatible driver or ORM.

We have tested the Java JDBC driver and the Hibernate ORM enough to claim beta-level support, so those are featured here. If you encounter problems, please open an issue with details to help us make progress toward full support.

{{site.data.alerts.callout_success}} For a more realistic use of Hibernate with CockroachDB, see our examples-orms repository. {{site.data.alerts.end}}

Before you begin

{% include {{page.version.version}}/app/before-you-begin.md %}

{{site.data.alerts.callout_danger}} The examples on this page assume you are using a Java version <= 9. They do not work with Java 10. {{site.data.alerts.end}}

Step 1. Install the Gradle build tool

This tutorial uses the Gradle build tool to get all dependencies for your application, including Hibernate.

To install Gradle on Mac, run the following command:

{% include copy-clipboard.html %}

$ brew install gradle

To install Gradle on a Debian-based Linux distribution like Ubuntu:

{% include copy-clipboard.html %}

$ apt-get install gradle

To install Gradle on a Red Hat-based Linux distribution like Fedora:

{% include copy-clipboard.html %}

$ dnf install gradle

For other ways to install Gradle, see its official documentation.

Step 2. Create the maxroach user and bank database

{% include {{page.version.version}}/app/create-maxroach-user-and-bank-database.md %}

Step 3. Generate a certificate for the maxroach user

Create a certificate and key for the maxroach user by running the following command. The code samples will run as this user.

{% include copy-clipboard.html %}

$ cockroach cert create-client maxroach --certs-dir=certs --ca-key=my-safe-directory/ca.key

Step 4. Convert the key file for use with Java

The private key generated for user maxroach by CockroachDB is PEM encoded. To read the key in a Java application, you will need to convert it into PKCS#8 format, which is the standard key encoding format in Java.

To convert the key to PKCS#8 format, run the following OpenSSL command on the maxroach user's key file in the directory where you stored your certificates (/tmp/certs in this example):

{% include copy-clipboard.html %}

$ openssl pkcs8 -topk8 -inform PEM -outform DER -in client.maxroach.key -out client.maxroach.pk8 -nocrypt

Step 5. Run the Java code

Download and extract hibernate-basic-sample.tgz, which contains a Java project that includes the following files:

File Description
Sample.java Uses Hibernate to map Java object state to SQL operations. For more information, see Sample.java.
hibernate.cfg.xml Specifies how to connect to the database and that the database schema will be deleted and recreated each time the app is run. For more information, see hibernate.cfg.xml.
build.gradle Used to build and run your app. For more information, see build.gradle.

In the hibernate-basic-sample directory, build and run the application:

{% include copy-clipboard.html %}

$ gradle run

Toward the end of the output, you should see:

1 1000
2 250

To verify that the table and rows were created successfully, start the built-in SQL client:

{% include copy-clipboard.html %}

$ cockroach sql --certs-dir=certs --database=bank

To check the account balances, issue the following statement:

{% include copy-clipboard.html %}

> SELECT id, balance FROM accounts;
+----+---------+
| id | balance |
+----+---------+
|  1 |    1000 |
|  2 |     250 |
+----+---------+
(2 rows)

Sample.java

The Java code shown below uses the Hibernate ORM to map Java object state to SQL operations. Specifically, this code:

  • Creates an accounts table in the database based on the Account class.

  • Inserts rows into the table using session.save(new Account()).

  • Defines the SQL query for selecting from the table so that balances can be printed using the CriteriaQuery<Account> query object.

{% include copy-clipboard.html %}

{% include {{page.version.version}}/app/hibernate-basic-sample/Sample.java %}

hibernate.cfg.xml

The Hibernate config (in hibernate.cfg.xml, shown below) specifies how to connect to the database. Note the connection URL that turns on SSL and specifies the location of the security certificates.

{% include copy-clipboard.html %}

{% include {{page.version.version}}/app/hibernate-basic-sample/hibernate.cfg.xml %}

build.gradle

The Gradle build file specifies the dependencies (in this case the Postgres JDBC driver and Hibernate):

{% include copy-clipboard.html %}

{% include {{page.version.version}}/app/hibernate-basic-sample/build.gradle %}

Step 2. Create the maxroach user and bank database

{% include {{page.version.version}}/app/insecure/create-maxroach-user-and-bank-database.md %}

Step 3. Run the Java code

Download and extract hibernate-basic-sample.tgz, which contains a Java project that includes the following files:

File Description
Sample.java Uses Hibernate to map Java object state to SQL operations. For more information, see Sample.java.
hibernate.cfg.xml Specifies how to connect to the database and that the database schema will be deleted and recreated each time the app is run. For more information, see hibernate.cfg.xml.
build.gradle Used to build and run your app. For more information, see build.gradle.

In the hibernate-basic-sample directory, build and run the application:

{% include copy-clipboard.html %}

$ gradle run

Toward the end of the output, you should see:

1 1000
2 250

To verify that the table and rows were created successfully, start the built-in SQL client:

{% include copy-clipboard.html %}

$ cockroach sql --insecure --database=bank

To check the account balances, issue the following statement:

{% include copy-clipboard.html %}

> SELECT id, balance FROM accounts;
+----+---------+
| id | balance |
+----+---------+
|  1 |    1000 |
|  2 |     250 |
+----+---------+
(2 rows)

Sample.java

The Java code shown below uses the Hibernate ORM to map Java object state to SQL operations. Specifically, this code:

  • Creates an accounts table in the database based on the Account class.

  • Inserts rows into the table using session.save(new Account()).

  • Defines the SQL query for selecting from the table so that balances can be printed using the CriteriaQuery<Account> query object.

{% include copy-clipboard.html %}

{% include {{page.version.version}}/app/insecure/hibernate-basic-sample/Sample.java %}

hibernate.cfg.xml

The Hibernate config (in hibernate.cfg.xml, shown below) specifies how to connect to the database. Note the connection URL that turns on SSL and specifies the location of the security certificates.

{% include copy-clipboard.html %}

{% include {{page.version.version}}/app/insecure/hibernate-basic-sample/hibernate.cfg.xml %}

build.gradle

The Gradle build file specifies the dependencies (in this case the Postgres JDBC driver and Hibernate):

{% include copy-clipboard.html %}

{% include {{page.version.version}}/app/insecure/hibernate-basic-sample/build.gradle %}

What's next?

Read more about using the Hibernate ORM, or check out a more realistic implementation of Hibernate with CockroachDB in our examples-orms repository.

{% include {{page.version.version}}/app/see-also-links.md %}