Warning - Cast is checking against the erased type

[Wally Hartshorn]

Here's a bit of code:

Configuration config = new PropertiesConfiguration("config.properties");
 
List<String> colNames = (List<String>) config.getList("colName");
 
doSomething(colNames);

On the assignment to colNames, Eclipse is giving me this warning:
"Type safety: The cast from List to List<String> is actually checking against the erased type List"

Is there any way to write this in a way that takes care of this warning?

If I change it to this:

Configuration config = new PropertiesConfiguration("config.properties");
 
List colNames =  config.getList("colName");
 
doSomething((List<String>) colNames);

I get the same warning, just on the 3rd line rather than the 2nd.

Any suggestions on how to make this code warning-free?

Thanks,
Wally

[Paul Clapham]

Change the PropertiesConfiguration class so that its getList() method returns a List<String> object.

[Wally Hartshorn]

Originally posted by Paul Clapham:
Change the PropertiesConfiguration class so that its getList() method returns a List<String> object.

Unfortunately that's not really an option, because PropertiesConfiguration is a 3rd party class from the Apache Commons Configuration project. (True, it's open source, so technically I could modify it, but I'd rather not have to maintain my own custom version.)

Thanks for the suggestion, though.

[Paul Clapham]

Then you're stuck with the warning. You can't avoid such warnings if you're interfacing generified code with legacy non-generic code.

[Marcos R Hernandez F]

Hi. If Paul Clapham is right (and I believe he is), the only thing you can do is add a @suppress warnings to the method. Given the circumstances.