RE: [lang] ClassCastException in Enum.compareTo with anonymous inner classes
Hi Jörg,
thanks for your quick response and your approach to solve this issue. But
anyway I think it should be possible to add these Enums to a Set without
throwing a ClassCastException regardless of which class, anonymous inner class
or whatever else the Enum is.
Samuel
-Original Message-
From: Jörg Schaible [mailto:[EMAIL PROTECTED]
Sent: Thursday, September 13, 2007 4:06 PM
To: Jakarta Commons Users List
Subject: RE: [lang] ClassCastException in Enum.compareTo with anonymous inner
classes
Hi Samuel,
Samuel Fleischle wrote on Thursday, September 13, 2007 3:51 PM:
> Hi,
> I updated from Commons Lang 2.1 to Commons Lang 2.3 and got
> some issues with the changed compareTo() method of Enum with
> anonymouse inner classes:
>
> Here is my simplified Enum:
>
>
> public class ItemStatus extends Enum
> {
>// --
> Static Fields
> public static final ItemStatus CANCEL = new
> ItemStatus("CANCEL", "Cancel");
>
>public static final ItemStatus SHIPPED = new
> ItemStatus("SHIPPED", "Shipped") {
> public String getDisplayName() {
> // do something special for this status
> }
>};
>
> public static final ItemStatus MOVED = new
> ItemStatus("MOVED", "Moved") {
> public String getDisplayName() {
> // do something special for this status
> }
>};
>
[snip]
> }
[snip]
> com.myapp.common.model.order.ItemStatus
> com.myapp.common.model.order.ItemStatus$1
> com.myapp.common.model.order.ItemStatus$2
>
> The compareTo-Method now tries to compare ItemStatus$1 with
> ItemStatus$2 and says to me, that my ItemStatus-Enums are
> different classes.
Well, obviously those *are* different classes.
> I saw in JIRA there are some other issues in
> ValuedEnum.compareTo(). Is there a bug in the
> Enum.compareTo() implementation which got changed in Lang 2.2?
IIRC, this was more about using different class loaders loading the EnumValue
class.
> Thanks in advance for any help or comment on this issue.
Why don't you factor out a (private) interface with this method? Write an
addition ctor that takes such an implementation and use otherwise a default
one. With this approach the enum class is always the same and the anonymous
class is of a different type. Make the an additional field in the enum class
keeping that implementation and declare it as transient for seamless
serialization.
- Jörg
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RE: [lang] ClassCastException in Enum.compareTo with anonymous inner classes
Hi,
I updated from Commons Lang 2.1 to Commons Lang 2.3 and got some issues with
the changed compareTo() method of Enum with anonymouse inner classes:
Here is my simplified Enum:
public class ItemStatus extends Enum
{
// -- Static Fields
public static final ItemStatus CANCEL = new ItemStatus("CANCEL",
"Cancel");
public static final ItemStatus SHIPPED = new ItemStatus("SHIPPED",
"Shipped") {
public String getDisplayName() {
// do something special for this status
}
};
public static final ItemStatus MOVED = new ItemStatus("MOVED", "Moved") {
public String getDisplayName() {
// do something special for this status
}
};
/** Contains each status. */
private static Set statuses;
// -- Instance Fields
/** Name to display in user interfaces. */
private final String displayName;
// --- Constructors
protected ItemStatus(String name, String displayName) {
super(name);
this.displayName = displayName;
System.out.println(this.getClass().getName());
buildStatusSet();
}
// --- Static Methods
/**
* Returns the item status enumeration object
* for the given status name.
*
* @param itemStatus
* name of the item status
* @return the enumeration object, or null if it does not
* exist
*/
public static ItemStatus valueOf(String itemStatus) {
return (ItemStatus) getEnum(ItemStatus.class, itemStatus);
}
// --- Public Methods
/**
* [EMAIL PROTECTED]
*/
// @Override
public final Class getEnumClass() {
return ItemStatus.class;
}
/**
* Gets all defined ItemStatus.
*
* @return the enum object List
* @see org.apache.commons.lang.enums.Enum#getEnumList(Class)
*/
public static List getEnumList() {
return getEnumList(ItemStatus.class);
}
public String getDisplayName() {
return displayName;
}
// --- Private Methods
/**
* Adds the status name to a Set of status names.
*/
private void buildStatusSet() {
if (statuses == null) {
statuses = new TreeSet();
}
statuses.add(this);
}
}
And I got the ClassCastExcetion in the private "buildStatusSet()-Method if I
try to add the status to the TreeSet. The TreeSet calls the compareTo-Method of
the Enum. In Commons Lang 2.2 this method was changed with an additional
comparison of the classes.
In my constructor I added a System.out.println of the instantiated classes and
got the following output for the classnames:
com.myapp.common.model.order.ItemStatus
com.myapp.common.model.order.ItemStatus$1
com.myapp.common.model.order.ItemStatus$2
The compareTo-Method now tries to compare ItemStatus$1 with ItemStatus$2 and
says to me, that my ItemStatus-Enums are different classes.
I saw in JIRA there are some other issues in ValuedEnum.compareTo(). Is there a
bug in the Enum.compareTo() implementation which got changed in Lang 2.2?
Thanks in advance for any help or comment on this issue.
Regards,
Sam
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