Mapping Guide

The best resource for learning how to map JDO entities is the DataNucleus website. Take a look at:

In addition, we have a couple of articles on specific mapping use cases:

Custom Value Types

The framework provides a number of custom value types. Some of these are wrappers around a single value (eg AsciiDoc or Password) while others map onto multiple values (eg Blob).

This section shows how to map each (and can be adapted for your own custom types or @Embedded values).

Mapping AsciiDoc

The AsciiDoc value type is used for documentation written using the AsciiDoc syntax:

In the domain entity, map AsciiDoc type using @Column(jdbcType = "CLOB"):

MyEntity.java

public class MyEntity ... {

    @Column(allowsNull = "false", jdbcType = "CLOB")
    @Property
    @Getter @Setter
    private AsciiDoc documentation;

}

in the webapp module, register the JDO specific converter by:

adding a dependency to this module:

pom.xml

<dependency>
    <groupId>org.apache.isis.valuetypes</groupId>
    <artifactId>isis-valuetypes-asciidoc-persistence-jdo</artifactId>
</dependency>

and adding reference the corresponding module in the AppManifest:

AppManifest.java

@Configuration
@Import({
        ...
        IsisModuleValAsciidocPersistenceJdo.java
        ...
})
public class AppManifest {
}

Mapping Markdown

The Markdown value type is used for documentation written using markdown:

In the domain entity, map Markdown type using @Column(jdbcType = "CLOB"):

MyEntity.java

public class MyEntity ... {

    @Column(allowsNull = "false", jdbcType = "CLOB")
    @Property
    @Getter @Setter
    private Markdown documentation;

}

in the webapp module, register the JDO specific converter by:

adding a dependency to this module:

pom.xml

<dependency>
    <groupId>org.apache.isis.valuetypes</groupId>
    <artifactId>isis-valuetypes-markdown-persistence-jdo</artifactId>
</dependency>

and adding reference the corresponding module in the AppManifest:

AppManifest.java

@Configuration
@Import({
        ...
        IsisModuleValMarkdownPersistenceJdo.java
        ...
})
public class AppManifest {
}

Mapping Blobs and Clobs

The JDO ObjectStore integration of DataNucleus ORM can automatically persist Blob and Clob values into multiple columns, corresponding to their constituent parts.

Blobs

To map a Blob, use:

MyEntity.java

public class MyEntity ... {

    @Persistent(defaultFetchGroup="false", columns = {
            @Column(name = "pdf_name"),                 (1)
            @Column(name = "pdf_mimetype"),             (2)
            @Column(name = "pdf_bytes")                 (3)
    })
    @Getter @Setter
    private Blob pdf;

}

1	string, maps to a varchar in the database
2	string, maps to a varchar in the database
3	byte array, maps to a Blob or varbinary in the database

Clobs

To map a Clob, use:

MyEntity.java

public class MyEntity ... {

    @Persistent(defaultFetchGroup="false", columns = {
            @Column(name = "xml_name"),                 (1)
            @Column(name = "xml_mimetype"),             (2)
            @Column(name = "xml_chars"                  (3)
                    , jdbcType = "CLOB"
            )
    })
    @Getter @Setter
    private Clob xml;

}

1	string, maps to a varchar in the database
2	string, maps to a varchar in the database
3	char array, maps to a Clob or varchar in the database