Exception IBATiS lazy loading 1:M

[dwsmith75]

Hello World,

I'm getting this exception when I enable lazy loading on SQLMaps and try to access the M side of a 1:M relationship. If I disable lazy loading all runs as expected. Another topic regarding this is http://forum.springframework.org/showthread.php?t=9730 which was solved by adding transactions. As you can see from the stack trace it is hitting the transaction manger by the exception is still thrown. I would greatly appreciate any help someone can give me


The Exception
-----------------

java.lang.NullPointerException
com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.endTransaction(SqlMapExecutorDelegate.java:465)
com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.endTransaction(SqlMapSessionImpl.java:134)
com.ibatis.sqlmap.engine.impl.SqlMapClientImpl.endTransaction(SqlMapClientImpl.java:107)
com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.autoEndTransaction(SqlMapExecutorDelegate.java:515)
com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:381)
com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:359)
com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.queryForList(SqlMapSessionImpl.java:90)
com.ibatis.sqlmap.engine.impl.SqlMapClientImpl.queryForList(SqlMapClientImpl.java:65)
com.ibatis.sqlmap.engine.mapping.result.loader.ResultLoader.getResult(ResultLoader.java:65)
com.ibatis.sqlmap.engine.mapping.result.loader.EnhancedLazyResultLoader$EnhancedLazyResultLoaderImpl.loadObject(EnhancedLazyResultLoader.java:97)
com.ibatis.sqlmap.engine.mapping.result.loader.EnhancedLazyResultLoader$EnhancedLazyResultLoaderImpl.invoke(EnhancedLazyResultLoader.java:80)
$java.util.List$$EnhancerByCGLIB$$7e9071fc.iterator(<generated>)
pcvm.reservation.domain.logic.ReservationServiceImpl.findReservation(ReservationServiceImpl.java:267)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:324)
org.springframework.aop.framework.AopProxyUtils.invokeJoinpointUsingReflection(AopProxyUtils.java:59)
org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:149)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:118)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:191)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:138)
org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:148)
$Proxy1.findReservation(Unknown Source)

SQLMap
----------

<resultMap id="reservationEntity-result" class="reservationEntity">
	<result property="reservationNumber" column="CVMB40B_NORESV"/>
	<result property="rentals" column="CVMB40B_NORESV" select="findRentals"/>
	[other boring stuff...]
</resultMap>

<resultMap id="reservationRentalEntity-result" class="reservationRentalEntity">
	<result property="vehicleNumber" column="CVMB40C_NOVEH"/>
	[other boring stuff...]
</resultMap>

<select id="findReservation" parameterClass="java.util.Map" resultMap="reservationEntity-result">
	SELECT *
	FROM
		PCVM.CVMB40B
	WHERE 
		CVMB40B_NORESV = #reservationNumber#
</select>

<select id="findRentals" parameterClass="java.lang.String" resultMap="reservationRentalEntity-result">
	SELECT *
	FROM
		PCVM.CVMB40C
	WHERE
		CVMB40C_NORENTL = #value#
</select>

Transaction Props
---------------------

<prop key="find*">PROPAGATION_REQUIRED</prop>

[/code]

[dwsmith75]

Well, I've found some information on this if anyone else is having the same problem http://sourceforge.net/forum/forum.p...orum_id=206693

[tdhaayushverma]

For me, The problem for me was in my DAO:

here is my implemented method:

public class PollDAOIbatis extends BaseDAO implements PollDAO {

protected SqlMapClient sqlMap = null;
protected final Log logger = LogFactory.getLog(getClass());

public void setSqlMapClient(SqlMapClient sqlMap) {
this.sqlMap = sqlMap;
}

public void createPoll(Poll poll) throws Exception {


try{
sqlMap.startTransaction();

sqlMap.insert("createPoll", poll);


sqlMap.commitTransaction();
}finally{
sqlMap.endTransaction();
}
}
}

Note: here I am using the sqlMap.insert() method.
Earlier I was using sqlMap.queryForObject() method.
Its by using the queryForObject() mothod I was getting the NPE , but changing it to insert() , turned the world around me.

Hope this works for you.