Frequently Asked Questions

General

What does “Doma” mean?

The name “Doma” comes from the “Dao Oriented database MApping framework”.

What is annotation processing?

Annotation processing is a mechanism for parsing annotations at compile time and using them to generate code or perform compile-time checks.

We use annotation processing for the following purposes:

  • Generating meta-classes from classes annotated with @Entity and @Domain.

  • Generating implementation classes for interfaces annotated with @Dao.

  • Validating SQL templates.

Runtime environment

Which version of JRE does Doma support?

JRE 8 and above.

Which libraries are required for Doma to work?

None.

Doma has no dependencies on other libraries.

Development environment

Which version of JDK does Doma support?

JDK 8 and above.

Which IDE do you recommend?

Doma works with both Eclipse and IntelliJ IDEA, but IntelliJ IDEA is recommended. This is because Eclipse’s annotation processing may behave differently from the JRE used in the production environment.

Which build tool do you recommend?

Gradle and Maven are both supported.

Where are the files output by annotation processing?

Gradle

Check build/generated/sources/annotationProcessor.

Maven

Check target/generated-sources/annotations.

Eclipse

Check the output destination directory in the annotation processing settings.

IntelliJ IDEA

See the above Gradle and Maven sections.

I get the message that the sql file is not found, but it exists. Why?

You may get the following message, though the file exists:

[DOMA4019] The file[META-INF/../select.sql] is not found from the classpath

You can avoid this error by configuring recommended settings for each build tool and IDE.

See Building an application.

Do you provide a tool to generate Java code from a database schema?

Yes.

We have the Doma CodeGen plugin that generates Java and SQL files from Database.

Features as a database access library

Does Doma generate SQL statements?

Yes, Doma generates the following statements:

  • SELECT

  • INSERT

  • DELETE

  • UPDATE

  • Stored procedure call

  • Stored function call

Is the generation of dynamic SQL statements supported?

There are two ways:

  • The SQL Templates.

  • The Criteria API.

See SQL templates and Criteria API for detail information.

Does Doma support fetching relationships like one-to-one or one-to-many?

Yes.

Doma provides the Criteria API to map database relationships to Java entities.

See association (Entityql) for detail information.

Does Doma provide a JDBC connection pooling feature?

No.

Use Doma together with a JDBC connection pool library such as HikariCP.