[IBATIS-750] Immutable POJO fails to load when lazyLoading is enabled

• Type: New Feature
• Status: Reopened
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0 Beta 9
• Component/s: Core
• Assignee: Clinton Begin
• Reporter: Jan Novotný
• Created: 18/Feb/10 16:32
• Updated: 21/Feb/10 16:20

Description

Immutable POJO fails to load when lazyLoading is enabled with exception:

Caused by: java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given
at net.sf.cglib.proxy.Enhancer.emitConstructors(Enhancer.java:721)
at net.sf.cglib.proxy.Enhancer.generateClass(Enhancer.java:499)
at net.sf.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:216)
at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:285)
at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:663)
at org.apache.ibatis.executor.loader.ResultObjectProxy$EnhancedResultObjectProxyImpl.createProxy(ResultObjectProxy.java:34)
at org.apache.ibatis.executor.loader.ResultObjectProxy.createProxy(ResultObjectProxy.java:17)
at org.apache.ibatis.executor.resultset.FastResultSetHandler.createResultObject(FastResultSetHandler.java:270)
at org.apache.ibatis.executor.resultset.FastResultSetHandler.getRowValue(FastResultSetHandler.java:170)
at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleRowValues(FastResultSetHandler.java:129)
at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleResultSet(FastResultSetHandler.java:105)
at org.apache.ibatis.executor.resultset.FastResultSetHandler.handleResultSets(FastResultSetHandler.java:95)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:40)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:55)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:41)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:90)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:68)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:59)
... 36 more

I guess the source of the problem is usage of static method:

Enhancer.create(type, new EnhancedResultObjectProxyImpl(target, lazyLoader));

That doesn't allow to specify constructor arguments, thought iBatis know them. This will effectively limit using immutable objects with iBatis as lazy loading is set globally and is pretty often used.