Opgen is a code generator used internally by the Open Anzo developers to generate jdbc bindings from SQL query definitions in XML files.

For most of Open Anzo, the source files for opgen are at:

anzo-repository/src/main/resources

e.g.:

nodecentric.common.xmlsql/User.sql:

<preparedstatements>
        
        <preparedstatement name="selectUser" inputs="long id" outputs="String userId,String passwordHash, long defaultRoleId, long defaultAclId,Long hend" results="ROW">
                SELECT USERID,PASSWORDHASH, DEFAULTROLEID, DEFAULTACLID,HEND FROM USERS WHERE ID = ? AND HEND IS NULL;
        </preparedstatement>
        ...
</preparedstatements>

this is run through the opgen code generator:

anzo-repository/build.xml

<project name="anzo-repository" default="db2sql" basedir=".">
        
        <taskdef name="sqllibrary" classname="org.openanzo.jdbc.utils.opgen.ant.CompositionTask" />
        ...
        <property name="anzo-layout-dir" value="${basedir}/src/main/resources/nodecentric" />
        <target name="wrappers" description="--> Builds java objects needed for Anzo.">
                <sqllibrary>
                ...
                        <preparedstatements destbase="${gen-src-dir}/" javaclass="org.openanzo.server.repository.rdb.sql.UsersRolesRdbWrapper" exception="org.openanzo.common.exceptions.AnzoException" excludenamespace="false" rethrowSQLException="true">
                                <fileset file="${xmlsql-statements-dir}/UsersRoles.sql" />
                        </preparedstatements>
                ...
                </sqllibrary>
        </target>
...
</project>

The result is the generated 'wrapper' classes: UserRdbWrapper