Connect Your Payara Cloud Application to a Neon PostgreSQL Database

Deploying a web application often means connecting to a database. In this guide, I'll show you how to connect a Jakarta EE application on Payara Cloud to a PostgreSQL database hosted on Neon.

Prerequisites

• A Jakarta EE sample application (or your own project)
• A Neon account (the free tier will work)
• Your Neon database connection details

Get Started With Neon

1. Sample Application If you don't have one, create a Jakarta EE web application from the Payara Starter page (Web Profile).

2. Create a Neon Account Sign up for a free Neon account. This will provide a default project and database for our example.

3. Get Connection Details Find your database connection details in your Neon dashboard:

• Database server
• JDBC URL
• Database name
• Database user
• Database user password

Connect from Your Application

1. Define a Datasource Use the @DataSourceDefinition annotation and MicroProfile Config to set up your datasource:

@ApplicationScoped
@DataSourceDefinition(name = "java:app/cloud-postgres",
       className = "org.postgresql.ds.PGSimpleDataSource",
       url = "${MPCONFIG=DB_URL}",
       databaseName = "${MPCONFIG=DB_NAME}",
       serverName = "${MPCONFIG=DB_SERVER}",
       user = "${MPCONFIG=DB_USER}",
       password = "${MPCONFIG=DB_PASSWORD}",
       properties = {"targetServerType=primary"})
public class OpenAIFactory {

    @Produces
    @PersistenceContext
    EntityManager entityManager;
   

}

2. Configure Persistence Update your persistence.xml to use the new datasource:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<persistence xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns="https://jakarta.ee/xml/ns/persistence"
             xsi:schemaLocation="https://jakarta.ee/xml/ns/persistence https://jakarta.ee/xml/ns/persistence/persistence_3_0.xsd"
             version="3.0">
    <persistence-unit name="pcloud" transaction-type="JTA">

        <jta-data-source>java:app/cloud-postgres</jta-data-source>

        <exclude-unlisted-classes>false</exclude-unlisted-classes>
        <properties>
            <property name="jakarta.persistence.schema-generation.database.action" value="create"/>
        </properties>

    </persistence-unit>
</persistence>

3. Add PostgreSQL Driver Include the PostgreSQL JDBC driver as a runtime dependency in your project.

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.7.1</version>
    <scope>runtime</scope>
</dependency>

Deploy to Payara Cloud

1. Create a Payara Cloud Account Sign up and create an application.

2. Set Environment Variables In Payara Cloud's Configuration, add MicroProfile Config properties matching what you defined in your code (DB_URL, DB_NAME, etc.) using your Neon connection details.

3. Deploy! Click "Deploy" under Revision Actions. Your app will be live and connected to your Neon database.

Troubleshooting Double-check your database connection settings if the deployment fails. Payara Cloud's logs will usually pinpoint the issue.

That's it! You've successfully connected your Payara Cloud application to a Neon PostgreSQL database. Get the full, detailed guide here for your offline use.