The Things We Do For Code

The hoops I jump through when I code. Hope to help you avoid the same mistakes.

[thethingswedoforcode]

Embeddable class should not have id

Encountered errors like this:

Exception Description: Class [class edu.chl.jesjos.jpa.core.Customer] has two @GeneratedValues: for fields [CUSTOMER.ID] and [ID]. Only one is allowed.

This was probably due to the fact the customer class had an embedded Address class that tried to generate an id of its own.

This would cause the Customer to have both its own id and that of the address. Bad!

[thethingswedoforcode]

Dependencies fuckup

Seems you have to make sure that the Java EE API comes after EclipseLink in your POM, otherwise all sorts of strange shit will go down.

Could look like this:

<dependencies>

        <dependency>

            <groupId>org.eclipse.persistence</groupId>

            <artifactId>eclipselink</artifactId>

            <version>2.0.0</version>

        </dependency>

        <dependency>

            <groupId>org.eclipse.persistence</groupId>

            <artifactId>org.eclipse.persistence.jpa.modelgen.processor</artifactId>

            <version>2.2.0</version>

            <scope>provided</scope>

        </dependency>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.8.2</version>

            <scope>test</scope>

        </dependency>

        <dependency>

            <groupId>org.eclipse.persistence</groupId>

            <artifactId>javax.persistence</artifactId>

            <version>2.0.3</version>

        </dependency>

        <dependency>

            <groupId>org.apache.derby</groupId>

            <artifactId>derbyclient</artifactId>

            <version>10.6.1.0</version>

        </dependency>

                <dependency>

            <groupId>javax</groupId>

            <artifactId>javaee-web-api</artifactId>

            <version>6.0</version>

            <scope>provided</scope>

        </dependency>

    </dependencies>

An annotation processor threw an uncaught exception. Consult the following stack trace for details. java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/persistence/PersistenceException

See the rest in this gist: https://gist.github.com/1226189