HI!

We have a legacy application with >300 tables, where ALL the properties of one Business Object are stored in a HashMap (global var), so get/set methods or field access is not an option.
For each table, we have to define a composite id and a timestamp (version) column.
We are looking for a generic class to serve (read/write properties) all tables.

I have searched in the forum and found several solutions to this, which I have all tried:

1. Composite UserType
Because the composite user type has to offer a list of its properties (getPropertyNames()), we would need one of these for each table. That would be a lot of extra classes.

2. PropertyAccessor/Getter/Setter
At runtime, the Getters and Setters are only supplied with the object, not with the property name. So, a generic Getter and Setter can't be implemented. We would need a Getter and Setter for each property in each class -> more than 6000 objects.

3. Dynamic component
Dynamic component can fill a HashMap, which sounds good at first. Problem is, we have to map composite-id and timestamp seperate in the mapping XML and Hibernate always kills the entire HashMap when writing the specified (all other) properties into it. Since the columns of the composite-id and timestamp also live in the HashMap, they are being lost in this process.

Are there any other mapping alternatives, while keeping our properties in that global HashMap?

Thanks!

Hibernate version:
3.2.0 cr2

Thomas

Use a dynamic component. You shouldn't be putting your DB id into it, though. You need something like

HI!

Yes, I thought about that when evaluating 3. But still it is preferrable that ALL properties are in the HashMap.

Is there another alternative?

Thomas

If you want the GlobalProperties object to be an entity, then you must have ids. However, you can map the id and timestamp twice: put them into the dynamic-component as well as the correct <composite-id> and <timestamp> elements. To do that, you have to map them using the formula attribute of <property>, instead of the column attribute as in my example.

HI!

Thanks, this helped.

Thomas

If you want the GlobalProperties object to be an entity, then you must have ids. However, you can map the id and timestamp twice: put them into the dynamic-component as well as the correct <composite-id> and <timestamp> elements. To do that, you have to map them using the formula attribute of <property>, instead of the column attribute as in my example.

HI!

Unfortunately, there is a problem with your suggestion:

Native SQL queries do not work anymore.

Hibernate now fetches the id ("catalog") and timestamp columns for the formulas when using HQL by using those columns 2 times in the select, but not when using native SQL:

Mapping:
<property name="CATALOG" type="string" formula="catalog"/>
<property name="TIMESTAMP" type="byte[]" formula="timestamp"/>

HQL example:
select catalog0_.catalog as catalog0_, catalog0_.timestamp as timestamp0_, catalog0_.ID as ID0_, catalog0_.INSDATE as INSDATE0_, catalog0_.INSUSER as INSUSER0_, catalog0_.WAEHRUNG as WAEHRUNG0_, catalog0_.MARKETPLACE as MARKETPL7_0_, catalog0_.FIRMA as FIRMA0_, catalog0_.NAME as NAME0_, catalog0_.SUPPLIERID as SUPPLIERID0_, catalog0_.DATUM as DATUM0_, catalog0_.BUYERID as BUYERID0_, catalog0_.MEDIUM as MEDIUM0_, catalog0_.SPRACHE as SPRACHE0_, catalog0_.VERSION as VERSION0_, catalog0_.BEMERKUNG as BEMERKUNG0_, catalog0_.FORMAT as FORMAT0_, catalog0_.UPDDATE as UPDDATE0_, catalog0_.UPDUSER as UPDUSER0_, catalog0_.catalog as formula0_, catalog0_.timestamp as formula1_ from catalog catalog0_ where CATALOG='ENO-S-0000'

When I use native SQL like this:
session.createSQLQuery("select * from catalog").addEntity("catalog").uniqueResult();

then the pseudo formula columns are of course null, leading to a null pointer exception:

Exception in thread "P2plus-0" java.lang.NullPointerException
at org.hibernate.loader.DefaultEntityAliases.intern(DefaultEntityAliases.java:133)
at org.hibernate.loader.DefaultEntityAliases.getSuffixedPropertyAliases(DefaultEntityAliases.java:106)
at org.hibernate.loader.DefaultEntityAliases.<init>(DefaultEntityAliases.java:52)
at org.hibernate.loader.ColumnEntityAliases.<init>(ColumnEntityAliases.java:16)
at org.hibernate.loader.custom.SQLCustomQuery.<init>(SQLCustomQuery.java:182)
at org.hibernate.engine.query.NativeSQLQueryPlan.<init>(NativeSQLQueryPlan.java:43)
at org.hibernate.engine.query.QueryPlanCache.getNativeSQLQueryPlan(QueryPlanCache.java:113)
at org.hibernate.impl.AbstractSessionImpl.getNativeSQLQueryPlan(AbstractSessionImpl.java:137)
at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:142)
at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:164)
at org.hibernate.impl.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:756)



Thomas

Are you using an XML dataset? addEntity(String) is for use with XML data, not data in a RDBMS. Use addEntity(Catalog.class) and try it again.

HI!

Same result.

Thomas

I get this same problem trying to use a native query. Did you find something that fixed this??

Thanx,
LES

You could use {}-notation or return-property to list all the properties of the class with the formulae, instead of using implicit column naming. It's a lot more verbose and takes more maintenance if your class changes, but it will work. If you have a class with a property realValue and a formula derivedValue, this is what you need: