I was getting a ClassCastException when I try to load a saved object.
It seems that Hibernate was trying to pass in a regular hibernate.Set instead of a SortedSet.

It seems that the order in which you list sets in the hbm file makes a difference when generating code. At least I find that all sets listed after a set that is sorted produce sorted sets in the generated code. But the hibernate core (correctly) doesn't do that. So it tries to pass in a regular set when the generated code is expecting a SortedSet.

Is this news? I did not find mention of it anywhere.

I'm using Hibernate 2.0.3 and the 2.0.2 extensions.

POJO collection attributes have to be of interface type. This means you can have a:

private Set myChildren = new HashSet();
private List myOthers = new ArrayList();

but not this:

private TreeSet myChildren...

This is actually one of the few limitations with Hibernate and described in the documentation. I hope that this was what you asked for.

thanks, but that isn't the problem.

The code generator is generating code that expects SortedSets even though the mapping doesn't call for them if the set mapping comes after a set mapping that is sorted.

Example (in pseudo-hbm :-)

<mapping>
<class name="SomeClass">
<set name="plainSet">
<one-to-many class="SomeOtherClass" />
</set>
<set name="sortedSet" sort="MySorter" >
<one-to-many class="YAClass" />
</set>
</class>
</mapping>

This generates

public class SomeClass
{
private Set plainSet; // plus Set-based getters and setters
private SortedSet sortedSet; // plus SortedSet-based getters and setters.
}

now, if I change the mapping:

<mapping>
<class name="SomeClass">
<set name="sortedSet" sort="MySorter" >
<one-to-many class="YAClass" />
</set>
<set name="plainSet">
<one-to-many class="SomeOtherClass" />
</set>
</class>
</mapping>


This generates

public class SomeClass
{
private SortedSet sortedSet; // plus SortedSet-based getters and setters.
private SortedSet plainSet; // plus SortedSet-based getters and setters.
}

However, the hibernate core correctly reads the hbm and tries to pass in a Set to the
setPlainSet() method which (in this case) is expecting a SortedSet, causing the ClassCastException.

So, I guess I'm saying this seems like a bug in the CodeGenerator.

-Linus

If anyone cares, I have a fix for the SortedSet problem I described.

Please try to use the latest version of hbm2java - this should be fixed a loooong time ago ;)

(anyway - what's your fix ?)

I am using extensions 2.0.2 which is what is listed as latest on the hibernate.org downloads page. Should I be using something else?

What was happening is that you were switching to a Sorted collection at the first mention of sort, and not switching back unless sort="unsorted" was explicitly stated.

My fix (I'll admit it's a hack, but so was yours (by your own admission. :-)

In ClassMapping doCollections():

String originalInterface = interfaceClass;
String originalImplementingClass = implementingClass;
String sorterClass = null;

[...]

// Small hack to switch over to sortedSet/sortedMap if sort is specified. (that is sort != unsorted)
String sort = collection.getAttributeValue("sort");
if ("unsorted".equals(sort) ||
"".equals(sort)) {
interfaceClass = originalInterface;
implementingClass = originalImplementingClass;
}
else {
if (!"natural".equals(sort)) {
sorterClass = sort;
}
if("map".equals(xmlName)) {
interfaceClass = SortedMap.class.getName();
implementingClass = TreeMap.class.getName();
} else if("set".equals(xmlName)) {
interfaceClass = SortedSet.class.getName();
implementingClass = TreeSet.class.getName();
}
}

[...]

// add an import and field for this collection
addImport(interfaceClassName);
if ( sorterClass != null )
{
this.sortClass = sorterClass;
addImport( sorterClass );
}

The bigger hack is that ClassMapping has a public member "sortClass" (above) that I access when generating code in my renderer so that I can generate code to create the collection. This is not a general solution, I admit. What I am trying to get was to make the
add<CollectionItem>() method generation work. You have it commented out.

I have made it work for me with the above hacks, but I'm currently having trouble getting the foreign class mappings for the collection items. This is largely due to me OO-oriented schema design wherein everything descends from a base DbObject class that has a bunch of stuff that every class wants to have. I'm sure I'm not doing it the Proper Way, and I'm about to give up and give in.

hehe - never give up - there are always a way out ;)

It would really be great if you could post a patch to the JIRA (and maybe even also post a hbm.xml that shows this error - just for completeness).

Regarding the add<Collection> stuff then yes - it's hard to get the "other side" since it's not explicitly modelled as such in the hbm.xml.

But please show ya' current code - i might wanna start working on it ;)

I suppose I can post something to JIRA. I've never done that before, but I'm sure I can figure it out...

WRT what I'm doing, maybe I could send you my hackup versions of ClassMapping, CodeGenerator, and BasicRenderer.

What I have working, at least for what I've tried so far, is:

given the mappings

<set name="attrs" table="StationAttrs" lazy="true"
cascade="all" >
<key column="stationId"/>
<composite-element class="&util_pkg;.DescribedProperty" >
<property name="name" type="string" />
<property name="value" type="string" />
<property name="description" type="string" />
</composite-element>
</set>

<set name="installedHardware"
lazy="true" inverse="true"
cascade="save-update" >
<key column="stationId" />
<one-to-many class="&isis_pkg;.InstalledHardware" />
</set>

<set name="stationLogEntries" lazy="true"
inverse="true" cascade="save-update"
sort="&sort_pkg;.LogSorter" >
<key column="stationId" />
<one-to-many class="&isis_pkg;.LogEntry" />
</set>

I get

public Set getAttrs() {
return this.attrs;
}

public void setAttrs(Set attrs) {
this.attrs = attrs;
}

public void addAttr(DescribedProperty aAttr) {
if ( null == this.getAttrs() )
setAttrs(new HashSet())
this.getAttrs().add(aAttr);
}

public Set getInstalledHardware() {
return this.installedHardware;
}

public void setInstalledHardware(Set installedHardware) {
this.installedHardware = installedHardware;
}

public void addInstalledHardware(InstalledHardware aInstalledHardware) {
if ( null == this.getInstalledHardware() )
setInstalledHardware(new HashSet())
this.getInstalledHardware().add(aInstalledHardware);
}
public SortedSet getStationLogEntries() {
return this.stationLogEntries;
}

public void setStationLogEntries(SortedSet stationLogEntries) {
this.stationLogEntries = stationLogEntries;
}

public void addStationLogEntry(LogEntry aStationLogEntry) {
if ( null == this.getStationLogEntries() )
setStationLogEntries(new TreeSet(new isis.LogSorter()))
this.getStationLogEntries().add(aStationLogEntry);
}


I'd like to be able to do the inverse relationship setting too.

The SortedSet problem was described in an earlier post. Did that make sense?

Thanks,
Linus
linus --> iris.washington.edu

please post them both as two seperate issues on the JIRA (and preferably as patches)