关于hibernate映射问题,急求!

1, 当reverse(映射)一个没有primary key的table时候,List l =dao.getAll(); 打印l.size()是正确的,但是打印出来的l为:[null],[null],[null],[null]...答应l里面的object的时候说nullpointer1, 当reverse(映射)一个有primary key的table时候,List l =dao.getAll(); 结果完全正确.可以打印每一个object了数据.急求兄弟们解决.能够让没有primary key的table也能够得到正确的结果.没有primary key的table的SrResource.hbm.xml
<hibernate-mapping>
    <class name="com.seagate.calib.bean.SrResource" table="SR_RESOURCE" schema="PARIS">
        <composite-id name="id" class="com.seagate.calib.bean.SrResourceId">
            <key-property name="site" type="java.lang.String">
                <column name="SITE" length="2" />
            </key-property>
            <key-property name="facility" type="java.lang.String">
                <column name="FACILITY" length="2" />
            </key-property>
            <key-property name="resourceId" type="java.lang.String">
                <column name="RESOURCE_ID" length="8" />
            </key-property>
            <key-property name="modelResource" type="java.lang.String">
                <column name="MODEL_RESOURCE" length="8" />
            </key-property>
            <key-property name="rftResourceId" type="java.lang.Long">
                <column name="RFT_RESOURCE_ID" precision="5" scale="0" />
            </key-property>
      </composite-id>
    </class>
</hibernate-mapping>有primary key的table的SUserPref.hbm.xml配置如下:
<hibernate-mapping>
    <class name="com.seagate.calib.bean.SUserPref" table="S_USER_PREF" schema="PARIS">
        <composite-id name="id" class="com.seagate.calib.bean.SUserPrefId">
            <key-property name="site" type="java.lang.String">
                <column name="SITE" length="2" />
            </key-property>
            <key-property name="facility" type="java.lang.String">
                <column name="FACILITY" length="2" />
            </key-property>
            <key-property name="userId" type="java.lang.String">
                <column name="USER_ID" length="8" />
            </key-property>
        </composite-id>
        <property name="pcHomePage" type="java.lang.String">
            <column name="PC_HOME_PAGE" length="40" not-null="true" />
        </property>
    </class>
</hibernate-mapping>