解决illegal access to loading collection

在一对多关系中，使用左连接（在配置文件中用“fetch=join”或者在Hsql中使用 left join fetch）都会报下面的错误
[
org.hibernate.PropertyAccessException: Exception occurred inside setter of com.ccdup.order.entity.OrderInfo.product  
    at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:89)  
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.setPropertyValues(AbstractEntityTuplizer.java:360)  
    at org.hibernate.tuple.entity.PojoEntityTuplizer.setPropertyValues(PojoEntityTuplizer.java:221)  
    at org.hibernate.persister.entity.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:3594)  
    at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:152)  
    at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:877)  
    at org.hibernate.loader.Loader.doQuery(Loader.java:752)  
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)  
    at org.hibernate.loader.Loader.doList(Loader.java:2228)  
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)  
    at org.hibernate.loader.Loader.list(Loader.java:2120)  
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)  
    at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:361)  
    at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)  
    at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1148)  
    at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)  
    at com.ccdup.order.dao.OrderInfoDao.findAllOrderInfo(OrderInfoDao.java:25)  
    at com.ccdup.test.TestOf.getAall(TestOf.java:25)  
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)  
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)  
    at java.lang.reflect.Method.invoke(Method.java:585)  
    at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99)  
    at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81)  
    at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)  
    at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75)  
    at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45)  
    at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:66)  
    at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35)  
    at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42)  
    at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)  
    at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52)  
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:45)  
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)  
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)  
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)  
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)  
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)  
Caused by: java.lang.reflect.InvocationTargetException  
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)  
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)  
    at java.lang.reflect.Method.invoke(Method.java:585)  
    at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:66)  
    ... 37 more  
Caused by: org.hibernate.LazyInitializationException: illegal access to loading collection  
    at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:363)  
    at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)  
    at org.hibernate.collection.PersistentSet.iterator(PersistentSet.java:186)  
    at com.ccdup.order.entity.OrderInfo.setProduct(OrderInfo.java:173)  
    ... 42 more 

/code]

解决方法：在配置文件一对多处加入access="field"，即

        <set
            name="customer"
            lazy="false"
            cascade="all"
            sort="unsorted"
            outer-join="true"

            access="field"

            fetch="join"
        >

加上之后“fetch=join”或者在Hsql中使用 left join fetch就不能实现连接了