Offline Integration Testing

A micro framework to make it easier to perform offline / local integration testing when using Spring and Hibernate within a Java backend.

Introduction

By providing the ability to simplify swapping out of the JPA based persistence configuration, a Data Access Layer and its objects can be tested quickly and easily to ensure that criteria and any other SQL/JPQL/HQL logic is performing as expected. This is achieved by utilising an in-memory database in order to run integration tests through a lightweight, low footprint, local database.

By default an in-memory H2 database instance is used but the configuration can easily be adjusted to fit requirements.

Getting Started

Implement the OfflineIntegrationSupport interface, extend the provided instance of OfflineIntegrationConfiguration and provide any persistence adjustments (including overriding getEntityPackagesToScan) or bean references you need.

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader=AnnotationConfigContextLoader.class)
public class MyIntegrationTest implements OfflineIntegrationSupport {

  @Configuration
  public static MyIntegrationTestConfiguration extends OfflineIntegrationConfiguration {
  
    @Override
    public String[] getEntityPackagesToScan() {
        return new String[] {"com.mypackage.model"};
    }
      ....
  }
}

Modifying OfflineIntegrationConfiguration

Specifying where to find model entities

Override getEntityPackagesToScan to provide an array of package names to be scanned for annotated Entity subclasses.

  @Override
  public String[] getEntityPackagesToScan() {
      return new String[] {"com.mypackage.model", "com.thirdpartylib.models"};
  }  

Adjusting JPA Properties

Override getJPAProperties if you want to adjust any JPA EntityManagerFactory / Hibernate SessionFactory properties.

   // To make sure you can see the SQL being created and used (this is off by default).
   @Override
   protected Properties getJPAProperties() {
      Properties properties = super.getJPAProperties();
      properties.setProperty(HibernateShowSQLPropertyName, "true");
      return properties;
   }

Overriding the data source configuration

Override getDataSourceUsername to specifiy your own username. (This is blank by default).

    @Override
    public String getDataSourceUsername() {
        return "myusername";
    }

Override getDataSourcePassword to specifiy your own password. (This is blank by default).

   @Override
   public String getDataSourcePassword() {
      return "mypassword";
   }

Override getDataSourceURL() to change the location and/or type of database used. (This is 'jdbc:h2:mem:test;DB_CLOSE_DELAY=-1' by default).

   @Override
   public String getDataSourceURL() {
      // Create the test database on the filesystem in the users home directory
      return "jdbc:h2:~/test";
   }

Switching to a different database provider

Override getDataSourceDriverClassName, getDialectPropertyClassName and getDataSourceURL to configure the connection to the database.

  // switch to local MySQL database for integration testing
  
  @Override
  public String getDataSourceDriverClassName() {
      return "com.mysql.jdbc.Driver";
  }
  
  @Override
  public String getDialectPropertyClassName() {
      return "org.hibernate.dialect.MySQL5Dialect";
  }
  
  @Override
  public String getDataSourceURL() {
      return "jdbc:mysql://localhost:3306/integration_testing";
  }

Sample code

A full example of utilising this framework both for testing and as a basis to configure a spring-based app is provided in the this repository.