Configuring Spring Boot for Oracle

When you start with Spring Boot, it will automatically support H2 if no other data sources have been defined and H2 is found on the classpath. I’ve been using H2 for development for sometime now. It works very well.  All modern relational databases are going to support ANSI SQL. But each is going to have its own nuances and extensions. One thing of the things I like about H2 is its Oracle compatibility mode. It allows H2 to act like a Oracle database. It’s not perfect, but it does do a pretty good job.

The Spring Framework is the most popular Java framework used for building enterprise class applications. Oracle is the most popular database used in the enterprise. So chances are, if you developing Spring Applications, sooner or later, you’re going to be persisting to an Oracle database.

Oracle Database Driver

The Oracle JDBC drivers are not in public Maven repositories due to legal restrictions. This is really rather annoying. Oracle, if you’re reading this – really? Come on, fix this. Please.

So, if you are in a company, chances are you will have a nexus installation with the Oracle JDBC jar installed. But if you are not, you will need to download the JDBC driver from Oracle (after accepting the terms and conditions you probably won’t read). And then you can install it into your local Maven repository manually.

You can install a JAR into your Maven repository using this Maven command. You may need to adjust the version and name depending on the JDBC driver version you download.

mvn install:install-file -Dfile=ojdbc7.jar  -DgroupId=com.oracle -DartifactId=ojdbc7 -Dversion=12.1.0.1 -Dpackaging=jar

Spring Boot Configuration for Oracle

Maven Dependency

You will need to add the Oracle Driver to your Maven (or Gradle) dependencies.

        <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc7</artifactId>
            <version>12.1.0.1</version>
        </dependency>

Oracle Datasource

The easiest approach is to create a configuration bean in the package structure of your Spring Boot application. This will create a new Oracle datasource for your Spring Boot application. Once you specify a data source, Spring Boot will no longer create the H2 data source for you automatically.

    @Bean
    DataSource dataSource() throws SQLException {

        OracleDataSource dataSource = new OracleDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setURL(url);
        dataSource.setImplicitCachingEnabled(true);
        dataSource.setFastConnectionFailoverEnabled(true);
        return dataSource;
    }

Spring Boot Configuration

Oracle Properties

In this example, I’m going to show you how to externalise the Oracle connection properties to a properties file.

In our Spring Boot application.properties file we want to set the following properties.

#Oracle connection
oracle.username=system
oracle.password=manager
oracle.url=jdbc:oracle:thin:@//spring.guru.csi0i9rgj9ws.us-east-1.rds.amazonaws.com:1521/ORCL

Next, on our Configuration class for Oracle, we want to add the following annotation:

@ConfigurationProperties("oracle")

This tells Spring to look for the property prefix of Oracle when binding properties. Now if our configuration class has a property called ‘whatever’, Spring would try to bind the property value of ‘oracle.whatever’ to the property in the configuration class.

Now if we add the following properties to our configuration class, Spring will use them in the creation of our Oracle data source.

    @NotNull
    private String username;

    @NotNull
    private String password;

    @NotNull
    private String url;

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setUrl(String url) {
        this.url = url;
    }

The final Oracle configuration class looks like this:

OracleConfiguration.class

package guru.springframework.configuration;

import oracle.jdbc.pool.OracleDataSource;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;

import javax.sql.DataSource;
import javax.validation.constraints.NotNull;
import java.sql.SQLException;

@Configuration
@ConfigurationProperties("oracle")
public class OracleConfiguration {
    @NotNull
    private String username;

    @NotNull
    private String password;

    @NotNull
    private String url;

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    @Bean
    DataSource dataSource() throws SQLException {

        OracleDataSource dataSource = new OracleDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setURL(url);
        dataSource.setImplicitCachingEnabled(true);
        dataSource.setFastConnectionFailoverEnabled(true);
        return dataSource;
    }
}

Hibernate Configuration

We will want to tell Hibernate to use the Oracle dialect. We do this by adding the following property to the Spring Boot application.properties file.

Required

spring.jpa.database-platform=org.hibernate.dialect.Oracle10gDialect

Optional

If you’re used to using the H2 database, database tables will automatically be generated by Hibernate. If you want the same behavior in Oracle, you’ll need to set the ddl-auto property of Hibernate to ‘create-drop’. The Spring Boot documentation has additional information about database initialization. To have tables automatically created in Oracle, set the following property in your application.properties file.

spring.jpa.hibernate.ddl-auto=create-drop

Amazon RDS

In testing the code for this post, I spooled up an Oracle instance using Amazon RDS. This makes creating an Oracle database crazy easy. If you want to test this out yourself, I’ve checked in the code on GitHub here. You can check it out, and setup your own Oracle instance on Amazon RDS. Just update the connection properties in application.properities. I branched the code from my tutorial series on building a web application with Spring Boot. Everything will work – EXCEPT create and save. Oracle handles ID generation a little differently and I did not update the JPA mapping for this.