OpenJPA, Tomcat 7, Eclipse & maven - enchance does not work

Question

So I've decided to give OpenJPA a go and so far I no luck. I followed this as best I could: http://struberg.wordpress.com/2012/01/08/jpa-enhancement-done-right/ org.apache.openjpa.persistence.ArgumentException: The type "class com.MyClass" has not been enhanced. is the problem.

I tried to follow this these steps to solve it since I'm pretty unfamiliar with ANT.

• Add maven plugin

      <plugin>
          <groupId>org.apache.openjpa</groupId>
          <artifactId>openjpa-maven-plugin</artifactId>
          <version>2.2.0</version>
          <configuration>
              <includes>com/myproject/core/domain/*.class</includes>
              <addDefaultConstructor>true</addDefaultConstructor>
              <enforcePropertyRestrictions>true</enforcePropertyRestrictions>
  
              <!-- Pass additional properties to the Plugin here -->
              <toolProperties>
                  <property>
                      <name>directory</name>
                      <value>otherdirectoryvalue</value>
                  </property>
              </toolProperties>
  
          </configuration>
          <executions>
              <execution>
                  <id>enhancer</id>
                  <phase>process-classes</phase>
                  <goals>
                      <goal>enhance</goal>
                  </goals>
              </execution>
          </executions>
  
          <dependencies>
              <dependency>
                  <groupId>org.apache.openjpa</groupId>
                  <artifactId>openjpa</artifactId>
                  <version>2.2.0</version>
              </dependency>
          </dependencies>
  
      </plugin>
  

  • So now when try I clean project then server, then use maven and mvn clean process-classes It then successfully enhances the classes I have specified.

  • Start server and try a simple persist that worked with hibernate and it gives me:

openjpa-2.2.0-r422266:1244990 fatal user error> org.apache.openjpa.persistence.ArgumentException: The type "class com.myproject.core.domain.MyClass" has not been enhanced. FailedObject: com.myproject.core.domain.MyClass@aecda16 [java.lang.String] at org.apache.openjpa.meta.ClassMetaData.resolveMeta(ClassMetaData.java:1823) at org.apache.openjpa.meta.ClassMetaData.resolve(ClassMetaData.java:1797) at org.apache.openjpa.meta.MetaDataRepository.processBuffer(MetaDataRepository.java:822) at org.apache.openjpa.meta.MetaDataRepository.resolveMeta(MetaDataRepository.java:719) at org.apache.openjpa.meta.MetaDataRepository.resolve(MetaDataRepository.java:643) at org.apache.openjpa.meta.MetaDataRepository.getMetaDataInternal(MetaDataRepository.java:411) at org.apache.openjpa.meta.MetaDataRepository.getMetaData(MetaDataRepository.java:384)

    <persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
    version="2.0">
    <persistence-unit name="myproj_pu"
        transaction-type="RESOURCE_LOCAL">
        <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
        <!-- MySQL -->
        <properties>
            <property name="openjpa.ConnectionURL" value="jdbc:mysql://localhost:3306/myproject" />
            <property name="openjpa.ConnectionDriverName" value="com.mysql.jdbc.Driver" />
            <property name="openjpa.ConnectionUserName" value="root" />
            <property name="openjpa.ConnectionPassword" value="1111" />
            <property name="openjpa.Log" value="DefaultLevel=WARN, Tool=INFO" />
        </properties>
    </persistence-unit>
</persistence>

Frankly I don't really understand how a reasonable work flow is supposed to look like with this even if I get it to work. Maybe use another strategy or something?

Would love some pointers and tips and of course help with the problem.

Cheers

Answer 1

I think the only thing you missed is adding the following line inside the "persistence-unit" element of your persistence.xml:

<class>com.MyClass</class>

The enhancer looks for these class definitions inside of persistence.xml so it knows which classes to enhance.