code: public Class getPersistentFieldClass()
      {
          if (m_persistenceClass == null)
          {
              Properties properties = new Properties();
              try
              {
                  this.logWarning("Loading properties file: " + getPropertiesFile());
                  properties.load(new FileInputStream(getPropertiesFile()));
              }
              catch (IOException e)
              {
                  this.logWarning("Could not load properties file '" + getPropertiesFile()
                          + "'. Using PersistentFieldDefaultImpl.");
                  e.printStackTrace();
              }
              try
              {
                  String className = properties.getProperty("PersistentFieldClass");
  
                  m_persistenceClass = loadClass(className);
              }
              catch (ClassNotFoundException e)
              {
                  e.printStackTrace();
                  m_persistenceClass = PersistentFieldPrivilegedImpl.class;
              }
              logWarning("PersistentFieldClass: " + m_persistenceClass.toString());
          }
          return m_persistenceClass;
      }
docs: Returns the Class object of the class specified in the OJB.properties
  file for the "PersistentFieldClass" property.
  
  @return Class The Class object of the "PersistentFieldClass" class
  specified in the OJB.properties file.