Upgrading from Spring Boot 2 to 3 and Hibernate 6: Conquering the Geometry Column Type Cast Exception

Are you ready to embark on a thrilling adventure of upgrading your Spring Boot application from version 2 to 3, and Hibernate from 5 to 6? Buckle up, folks, because this journey is not for the faint of heart! In this article, we’ll navigate the treacherous waters of geometry columns and type cast exceptions, emerging victorious with a shiny new application that’s ready to take on the world.

The Challenge: Geometry Columns in Hibernate 6

Hibernate 6 brings a plethora of exciting features and improvements, but it also introduces some significant changes that can catch you off guard. One of these changes is the way geometry columns are handled. If you’re using geometry columns in your application, you might encounter a type cast exception when trying to access or manipulate the data.

What are Geometry Columns?

Geometry columns are a type of spatial data that allows you to store and query geographic data, such as points, lines, and polygons. They’re commonly used in applications that require location-based features, like mapping, routing, and proximity searches.

@Entity
public class Location {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    @Column(columnDefinition = "geometry")
    private Point location;
    
    // getters and setters
}

In the example above, we have a `Location` entity with a `location` field of type `Point`, which is a geometry column.

The Problem: Type Cast Exception

When you upgrade to Hibernate 6, you might encounter a type cast exception when trying to access or manipulate the geometry column data. This is because Hibernate 6 uses a different type mapping for geometry columns.

java.lang.ClassCastException: org.hibernate.spatial.dialect.oracle.OracleSpatialGeometry cannot be cast to com.vividsolutions.jts.geom.Geometry

This exception occurs because Hibernate 6 uses the `OracleSpatialGeometry` type, which is not compatible with the `com.vividsolutions.jts.geom.Geometry` type used in Hibernate 5.

The Solution: Upgrading to Hibernate Spatial

To overcome the type cast exception, you need to upgrade to Hibernate Spatial, which provides support for spatial data types in Hibernate 6.

Dependency Upgrades

First, you need to upgrade your dependencies to include Hibernate Spatial. Add the following dependencies to your `pom.xml` file (if you’re using Maven) or your `build.gradle` file (if you’re using Gradle):

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-spatial</artifactId>
    <version>6.0.2.Final</version>
</dependency>
<dependency>
    <groupId>jakarta.xml.bind</groupId>
    <artifactId>jakarta.xml.bind-api</artifactId>
    <version>3.0.0</version>
</dependency>
<dependency>
    <groupId>com.vividsolutions</groupId>
    <artifactId>jts</artifactId>
    <version>1.18.1</version>
</dependency>

or

dependencies {
    implementation 'org.hibernate:hibernate-spatial:6.0.2.Final'
    implementation 'jakarta.xml.bind:jakarta.xml.bind-api:3.0.0'
    implementation 'com.vividsolutions:jts:1.18.1'
}

Type Mappings

Next, you need to update your type mappings to use the correct types. In your `application.properties` or `application.yml` file, add the following configuration:

spring.jpa.properties.hibernate.spatial.dialect=org.hibernate.spatial.dialect.h2geodb.GeoDBDialect
spring.jpa.properties.hibernate.jpa.model_generator.scan.enhance=true

or

spring:
  jpa:
    properties:
      hibernate:
        spatial:
          dialect: org.hibernate.spatial.dialect.h2geodb.GeoDBDialect
        jpa:
          model_generator:
            scan:
              enhance: true

Entity Updates

Finally, you need to update your entity classes to use the correct types. In our `Location` entity example, we need to change the `location` field type to `org.hibernate.spatial Geometry`:

@Entity
public class Location {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    @Column(columnDefinition = "geometry")
    @Type(type = "org.hibernate.spatial.GeometryType")
    private org.hibernate.spatial.Geometry location;
    
    // getters and setters
}

Conclusion

Upgrading from Spring Boot 2 to 3 and Hibernate 5 to 6 can be a challenging task, especially when dealing with geometry columns. By following the steps outlined in this article, you should be able to overcome the type cast exception and successfully upgrade your application.

Best Practices

Remember to always follow best practices when working with spatial data:

• Use the correct data types for your spatial data (e.g., `Point`, `LineString`, `Polygon`)
• Define the correct spatial reference system (SRS) for your data
• Use spatial indexes to improve query performance
• Test your spatial queries thoroughly to ensure correct results

By following these best practices and upgrading to Hibernate Spatial, you’ll be able to take full advantage of the new features and improvements in Hibernate 6.

Frequently Asked Questions

Q: Do I need to upgrade to Hibernate Spatial to use geometry columns in Hibernate 6?

A: Yes, Hibernate Spatial is required to use geometry columns in Hibernate 6.

Q: Can I use Hibernate 5 geometry columns with Hibernate 6?

A: No, Hibernate 6 uses a different type mapping for geometry columns, which is not compatible with Hibernate 5.

Q: What is the difference between Hibernate Spatial and Hibernate 6?

A: Hibernate Spatial is a separate module that provides support for spatial data types in Hibernate, whereas Hibernate 6 is the main ORM (Object-Relational Mapping) tool.

Feature	Hibernate 5	Hibernate 6
Geometry Columns	com.vividsolutions.jts.geom.Geometry	org.hibernate.spatial.Geometry
Spatial Support	Limited	Enhanced with Hibernate Spatial

I hope this article has been informative and helpful in your journey to upgrading from Spring Boot 2 to 3 and Hibernate 5 to 6. Happy coding!

Frequently Asked Question

Are you facing issues while upgrading from Spring Boot 2 to 3 and Hibernate 6, specifically with geometry column throwing type cast exception? Don’t worry, we’ve got you covered! Here are some frequently asked questions and answers to help you resolve the issue.