Putting it all together

You now have a full set of implemented setter methods. Here's the code so far:
Figure 1. Complete listing for an entity implementation with implemented setter methods
package curam.mypackage;

import java.util.Set;

import com.google.inject.Inject;

import curam.mypackage.struct.MyNewEntityDtls;
import curam.util.exception.InformationalException;
import
  curam.util.persistence.helper.SingleTableLogicallyDeleteableEntityImpl;
import curam.util.type.Date;
import curam.util.type.DateRange;
import curam.util.type.StringHelper;

/**
 * Standard implementation of {@linkplain MyNewEntity}.
 */
public class MyNewEntityImpl extends
    SingleTableLogicallyDeleteableEntityImpl<MyNewEntityDtls>
    implements MyNewEntity {

  @Inject
  private MyParentEntityDAO myParentEntityDAO;

  @Inject
  private MyChildEntityDAO myChildEntityDAO;

  protected MyNewEntityImpl() {
    /* Protected no-arg constructor for use only by Guice */
  }

  /*
   * Field getters
   */

  /**
   * {@inheritDoc}
   */
  public String getName() {
    return getDtls().name;
  }

  /**
   * {@inheritDoc}
   */
  public DateRange getDateRange() {
    return new DateRange(getDtls().startDate, getDtls().endDate);
  }

  /**
   * {@inheritDoc}
   */
  public MYNEWENTITYTYPEEntry getType() {
    return MYNEWENTITYTYPEEntry.get(getDtls().typeCode);
  }

  /*
   * Related-entity getters
   */
  /**
   * {@inheritDoc}
   */
  public Set<MyChildEntity> getMyChildren() {
    return myChildEntityDAO.searchByParent(this);
  }

  /**
   * {@inheritDoc}
   */
  public MyParentEntity getMyParentEntity() {
    final long myParentEntityID = getDtls().myParentEntityID;

    if (myParentEntityID == 0) {
      return null;
    } else {
      return myParentEntityDAO.get(myParentEntityID);
    }
  }

  /*
   * Setters
   */

  /**
   * {@inheritDoc}
   */
  public void setMyParentEntity(final MyParentEntity value) {
    final long myParentEntityID;
    if (value == null) {
      myParentEntityID = 0;
    } else {
      myParentEntityID = value.getID();
    }

    getDtls().myParentEntityID = myParentEntityID;
  }

  /**
   * {@inheritDoc}
   */
  public void setName(final String value) {
    getDtls().name = StringHelper.trim(value);
  }

  /**
   * Sets the start and end fields from the date range supplied.
   *
   * @param value
   *          the date range supplied
   */
  private void setDateRange(final DateRange value) {
    getDtls().startDate = value.start();
    getDtls().endDate = value.end();
  }

  /**
   * {@inheritDoc}
   */
  public void setType(final MYNEWENTITYTYPEEntry value) {
    getDtls().typeCode = value.getCode();
  }

  /*
   * Validation
   */
  public void mandatoryFieldValidation() {
    // TODO Auto-generated method stub

  }

  public void crossFieldValidation() {
    // TODO Auto-generated method stub

  }

  public void crossEntityValidation() {
    // TODO Auto-generated method stub

  }

  /**
   * Defaults:
   * <ul>
   * <li>the type to {@linkplain MYNEWENTITYTYPEEntry#SOMETYPE};
   * and</li>
   * <li>the date range to {@linkplain DateRange#todayOnwards()}.
   * </li>
   * </ul>
   */
  public void setNewInstanceDefaults() {
    setType(MYNEWENTITYTYPEEntry.SOMETYPE);
    setDateRange(DateRange.todayOnwards());
  }

}