Hibernate / hsqldb 2 cannot hydrate Blob column

Question

I am trying to load an object with byte data (annotated using @Lob) from an HSQL 2.0 database using Hibernate 3.5.6. This object can be saved without any problems and loaded perfectly if it is in the cache (i.e. no need to dehydrate). However, when the object is not in the cache (it needs to be moistened), I get the following exception:

Caused by: org.hsqldb.HsqlException: incompatible data type in conversion: from SQL type BLOB to [B, value: instance of org.hsqldb.types.BlobDataID
    at org.hsqldb.error.Error.error(Unknown Source)
    ... 68 more

Here is a complete stack trace (minus some domain-specific trace) for more context:

javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1235)
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1168)
...

Caused by: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.loader.Loader.doList(Loader.java:2452)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2192)
at org.hibernate.loader.Loader.list(Loader.java:2187)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:452)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1258)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:241)
... 45 more

Caused by: java.sql.SQLSyntaxErrorException: incompatible data type in conversion: from SQL type BLOB to [B, value: instance of org.hsqldb.types.BlobDataID
at org.hsqldb.jdbc.Util.sqlException(Unknown Source)
at org.hsqldb.jdbc.Util.throwError(Unknown Source)
at org.hsqldb.jdbc.JDBCResultSet.getColumnInType(Unknown Source)
at org.hsqldb.jdbc.JDBCResultSet.getBytes(Unknown Source)
at org.hsqldb.jdbc.JDBCResultSet.getBytes(Unknown Source)
at org.hibernate.type.AbstractBynaryType.get(AbstractBynaryType.java:103)
at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:186)
at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:175)
at org.hibernate.type.AbstractType.hydrate(AbstractType.java:105)
at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:2267)
at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1443)
at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1371)
at org.hibernate.loader.Loader.getRow(Loader.java:1271)
at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:619)
at org.hibernate.loader.Loader.doQuery(Loader.java:745)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:270)
at org.hibernate.loader.Loader.doList(Loader.java:2449)
... 53 more
Caused by: org.hsqldb.HsqlException: incompatible data type in conversion: from SQL type BLOB to [B, value: instance of org.hsqldb.types.BlobDataID
at org.hsqldb.error.Error.error(Unknown Source)
... 68 more

, Hibernate 3.5.6 HSQL 1.8.0.10, , - ( Blob HSQL 1.8). , Hibernate, , HSQL 2, , HSQL . , MySQL.

, , Lob, :

@Entity
public class ImageEntity extends IdEntity {

    @Lob
    @Column(name="IMAGE")
    private byte[] imageBytes;
    ...

Hibernate/HSQL 2.0?

Answer 1

JDBCResultSet.java(HSQLDB 2.0.0, Sourceforge) getBytes. HSQLDB 2.0 blob, 1.8. * , , JDBC. getBytes :

public byte[] getBytes(int columnIndex) throws SQLException {

    Type sourceType = resultMetaData.columnTypes[columnIndex-1];
    if (sourceType.isLobType()){
        Blob b = getBlob(columnIndex);
        return b.getBytes(1, (int)b.length());
    }

    Object x = getColumnInType(columnIndex, Type.SQL_VARBINARY);

    if (x == null) {
        return null;
    }

    return ((BinaryData) x).getBytes();
}

:

public byte[] getBytes(int columnIndex) throws SQLException {

    Object x = getColumnInType(columnIndex, Type.SQL_VARBINARY);

    if (x == null) {
        return null;
    }

    return ((BinaryData) x).getBytes();
}