Seen this one? http://radio.weblogs.com/0122027/stories/2003/04/01/JavasCheckedExceptionsWereAMistake.html
Seems like a potentially nice compromise... Doesn't seem like it's gained much traction, though. Sunburned Surveyor wrote: > Roger that. I've done quite a bit of reading on the checked versus > unchecked exceptions myself. > > Thanks for the help. > > The Sunburned Surveyor > > On Wed, Oct 22, 2008 at 1:52 PM, Martin Davis <[EMAIL PROTECTED]> wrote: > >> Seems like a reasonable direction to me. The question of checked VS >> unchecked has been debated endlessly in the Java world, with no final >> resolution that I can see. Bottom line is that if you want to throw an >> exception from FeatureCollection it *has* to be unchecked. The good >> news is that if you *are* being a cowboy, there'll be a lot of other >> buckaroos ridin' the range with ya. >> >> Sunburned Surveyor wrote: >> >>> Martin, >>> >>> I had thought about converting the IOException to a Runtime Exception. >>> The only thing I don't like about this technique is that the client >>> code using the library has no control over how the Runtime Exception >>> is handled. Of course, I guess you could argue that client code >>> shouldn't need control over the exception handling, since Exceptions >>> weren't declared as part of the interface to begin with. >>> >>> Perhaps I have a unique case. >>> >>> I can't remember, but if you can catch a RuntimeException in the >>> client code, this would be a good approach. I can explain in the >>> Javadoc for my libraries methods which Runtime Exceptions are thrown >>> by my implementations of the interface, and why they are thrown. >>> >>> The Sunburned Surveyor >>> >>> On Wed, Oct 22, 2008 at 1:28 PM, Martin Davis <[EMAIL PROTECTED]> wrote: >>> >>> >>>> You could map the checked Exception into an unchecked one (and chain the >>>> original exception). This isn't going to make any difference to the >>>> calling code, because it isn't expecting *any* exceptions, let alone >>>> checked IOExceptions. >>>> >>>> There is a school of thought that contends that Java checked exceptions >>>> are a failed experiment - and I think that this sort of situation is the >>>> kind of thing they use to make their case. >>>> >>>> If you would like other precedent, Spring uses exception mapping to >>>> dramatically simplify their JDBC adapter framework (and they use >>>> unchecked exceptions, being heavily in the above school). >>>> >>>> Sunburned Surveyor wrote: >>>> >>>> >>>>> As part of my work on a FeatureCache for OpenJUMP I needed to write a >>>>> class that implemented the FeatureCollection interface. I ran into an >>>>> interesting problem while doing this. I'd like to get some advice from >>>>> my more experienced programmers. >>>>> >>>>> Take (as an example) the add method of the FeatureCollection >>>>> interface. It does not throw any Exception objects. I believe this >>>>> means that implementations of this method can only throw runtime >>>>> exceptions. However, my implementation of this method in the >>>>> FeatureCache depends on IO operations. These IO operations throw >>>>> IOExceptions. They are not runtime exceptions, so I can't rethrow them >>>>> from my add method eimplementation. I don't want to just eat the >>>>> IOException, or return null from the method, because then my poor >>>>> OpenJUMP user won't know what is wrong. My recent reading in the book >>>>> Hardcore Java also made me realize it isn't appropriate to print a >>>>> message and/or stack trace to the System console, because the user may >>>>> never see this. >>>>> >>>>> Here is what I was thinking might be a solution. I'll add a >>>>> setErrorHandler method to my FeatureCache. It will accept any >>>>> implementation of the ErrorHandler interface, which will define a >>>>> single method. This method will look something like this: >>>>> >>>>> public void handleThrowable(Throwable someError) >>>>> >>>>> I can then access this ErrorHandler object from within the >>>>> FeatureCache. This would allow me to handle an IOException from within >>>>> my add method in a way that is appropriate for the handler code. When >>>>> I integrate the FeatureCache into OpenJUMP I could flash a warning on >>>>> the workbench GUI using this mechanism. >>>>> >>>>> Are there any comments on this idea? How do you guys handle similar >>>>> situations, where you are writing a library that implements an >>>>> interface outside the library, and you need to handle/throw undeclared >>>>> exceptions? >>>>> >>>>> Is there an established design pattern for the solution I describe above? >>>>> >>>>> Thanks, >>>>> >>>>> The Sunburned Surveyor >>>>> >>>>> ------------------------------------------------------------------------- >>>>> This SF.Net email is sponsored by the Moblin Your Move Developer's >>>>> challenge >>>>> Build the coolest Linux based applications with Moblin SDK & win great >>>>> prizes >>>>> Grand prize is a trip for two to an Open Source event anywhere in the >>>>> world >>>>> http://moblin-contest.org/redirect.php?banner_id=100&url=/ >>>>> _______________________________________________ >>>>> Jump-pilot-devel mailing list >>>>> Jump-pilot-devel@lists.sourceforge.net >>>>> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>>>> >>>>> >>>>> >>>>> >>>> -- >>>> Martin Davis >>>> Senior Technical Architect >>>> Refractions Research, Inc. >>>> (250) 383-3022 >>>> >>>> >>>> ------------------------------------------------------------------------- >>>> This SF.Net email is sponsored by the Moblin Your Move Developer's >>>> challenge >>>> Build the coolest Linux based applications with Moblin SDK & win great >>>> prizes >>>> Grand prize is a trip for two to an Open Source event anywhere in the world >>>> http://moblin-contest.org/redirect.php?banner_id=100&url=/ >>>> _______________________________________________ >>>> Jump-pilot-devel mailing list >>>> Jump-pilot-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>>> >>>> >>>> >>> ------------------------------------------------------------------------- >>> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge >>> Build the coolest Linux based applications with Moblin SDK & win great >>> prizes >>> Grand prize is a trip for two to an Open Source event anywhere in the world >>> http://moblin-contest.org/redirect.php?banner_id=100&url=/ >>> _______________________________________________ >>> Jump-pilot-devel mailing list >>> Jump-pilot-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>> >>> >>> >> -- >> Martin Davis >> Senior Technical Architect >> Refractions Research, Inc. >> (250) 383-3022 >> >> >> ------------------------------------------------------------------------- >> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge >> Build the coolest Linux based applications with Moblin SDK & win great prizes >> Grand prize is a trip for two to an Open Source event anywhere in the world >> http://moblin-contest.org/redirect.php?banner_id=100&url=/ >> _______________________________________________ >> Jump-pilot-devel mailing list >> Jump-pilot-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >> >> > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > -- Martin Davis Senior Technical Architect Refractions Research, Inc. 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