ClassCastException when binding a MaterializedNClobType value as NClob
Description
org.hibernate.type.MaterializedNClobType has:
org.hibernate.type.descriptor.java.StringTypeDescriptor#INSTANCE as its JavaTypeDescriptor
org.hibernate.type.descriptor.sql.NClobTypeDescriptor#DEFAULT as its SqlTypeDescriptor
When org.hibernate.type.descriptor.sql.NClobTypeDescriptor binds a String as an NClob, it calls StringTypeDescriptor#unwrap to "unwrap" the NClob.
StringTypeDescriptor#unwrap checks if Clob is assignable from the expected type (NClob). Since NClob extends Clob, a Clob is created and returned. This ultimately causes a ClassCastException when binding the returned value as an NClob.
The fix simply moves the check for an NClob before the check for a Clob, so that an NClob will be returned instead.
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Former user June 14, 2017 at 8:47 PM
Fixed in master and 5.1 branches.
I've included tests for with the test case added for this issue. (already fixed in master; will be fixed in 5.1 shortly).
org.hibernate.type.MaterializedNClobTypehas:org.hibernate.type.descriptor.java.StringTypeDescriptor#INSTANCE as itsJavaTypeDescriptororg.hibernate.type.descriptor.sql.NClobTypeDescriptor#DEFAULTas itsSqlTypeDescriptorWhen
org.hibernate.type.descriptor.sql.NClobTypeDescriptorbinds aStringas anNClob, it callsStringTypeDescriptor#unwrapto "unwrap" theNClob.StringTypeDescriptor#unwrapchecks ifClobis assignable from the expected type (NClob). SinceNClobextendsClob, aClobis created and returned. This ultimately causes aClassCastExceptionwhen binding the returned value as anNClob.The fix simply moves the check for an
NClobbefore the check for aClob, so that anNClobwill be returned instead.