Groups > comp.lang.java.programmer > #33628

Re: Java Checked Exception is BAD!

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From	Robert Klemme <shortcutter@googlemail.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Java Checked Exception is BAD!
Date	Sat, 6 Feb 2016 16:01:50 +0100
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On 06.02.2016 01:09, boxzou@gmail.com wrote:
> On Friday, 5 February 2016 11:47:16 UTC-5, Eric Douglas  wrote:
>> On Friday, February 5, 2016 at 11:26:04 AM UTC-5, box...@gmail.com wrote:
>>> by "rarely" I mean if you have a call stack where method3 calls method2 which calls method1:
>>>
>>> method1()
>>> method2()
>>> method3()
>>>
>>> when method1 throws an exception and method3 knows how to handle it, method2 should not be forced to handle.  In real application the call stack can be very steep (many method calls) and for an exception only one frame/method knows how to handle the exception.  The other frames/methods should not be forced to handle it.  That's what I meant by "rarely".
>>>
>>> In application server case, usually most exceptions are just logged by the application server so that the application (and server) does not crash on an exception.  There are very limited an app can do on most exceptions, like network outage, file accidentally removed, data accidentally removed from db, or due to bugs, these would usually require human intervention (fix network outage, put file back, fix data, fix bug etc).
>>
>> You still don't get it, and you still have yet to show a good example of how what you perceive to be a problem should be solved.
>> How can any method "not be forced to handle" any exception?  If method3 calls method2 which calls method1 and method1 encounters an exception do you think the norm should be to log the exception and continue as if nothing is wrong, or how do you propose method1 should tell method3 about the problem without telling method2?  It could throw an unchecked exception, which method2 wouldn't have to do anything for and method3 could still catch, but the programmer writing method3 still needs to know about the possibility of this exception and code for it.  It sounds like you're just making the huge assumption that causes many of the program errors in any language, that every programmer just knows every possible runtime error and writes handlers for them.
>
> As you said, if a runtime exception is thrown from method1 and method2 does not know how to handle it, method2 does not need to do anything and method3 can still catch that exception and handle it.  The developer need know method2 might throw this exception.  I am afraid we can not rely on checked exception to document this exception.  Why?  Suppose we have
>
> method3 calls method2a and method2b and method2c
> method2a calls method1a1 and method1a2 and method1a3
> method2b calls method1b1 and mehtod1b2 and method1b3
> method2c calls method1c1 and mehtod1c2 and method1c3
> and each method1xy throws one exception say Exception1xy
> now method3 signature would be
> method3(...)throws Exception1a1, Exception1ab, Exception1a3, Exception1b1, Exception1b2, Exception1b3, Exception1c1, Exception1c2, Exception1c3
>
> Do you think this will scale?  That's why JDBC has SQLException and SpringFramework/JPA/Guice abandons checked exception altogether.

I don't know why they did it.  Can you provide any references to the 
reasoning of those projects to abandon checked exceptions?

> This is only 3 levels, enterprise applications sometimes have 20+ levels. the throws clause would grow exponentially for each method.  Soon the code would be nothing but exceptions!

This is silly - for a number of reasons:
  - all intermediate methods can choose what exception to catch 
themselves and what they throw.
  - they can especially choose to throw another exception type wrapping 
the original one.
  - inheritance also works for exceptions

Hiding exception conditions does not make all the ways go away in which 
various functionalities can fail.  You need flexible and robust ways to 
handle them.  That's what you get with exceptions.

Cheers

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

Thread

Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 07:18 -0800
  Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-04 08:15 -0800
    Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-04 17:57 +0100
      Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-04 10:09 -0800
        Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-04 21:01 +0100
          Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-04 12:14 -0800
          Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-04 15:16 -0500
            Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-04 21:37 +0100
              Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-04 13:08 -0800
                Re: Java Checked Exception is BAD! 4ndre4 <4ndre4@4ndre4.com.invalid> - 2016-02-04 21:16 +0000
                Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-04 13:28 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-04 23:11 +0000
                Re: Java Checked Exception is BAD! a.laforgia@gmail.com - 2016-02-05 04:21 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-05 13:07 +0000
              Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-04 18:04 -0500
                Re: Java Checked Exception is BAD! Gene Wirchenko <genew@telus.net> - 2016-02-05 11:40 -0800
          Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-04 23:22 +0100
          Re: Java Checked Exception is BAD! ruben <ceo@iran.gov> - 2016-02-15 11:45 +0000
      Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 11:57 -0800
        Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-04 21:07 +0100
    Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 11:10 -0800
      Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-04 11:28 -0800
        Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 11:33 -0800
          Re: Java Checked Exception is BAD! 4ndre4 <4ndre4@4ndre4.com.invalid> - 2016-02-04 21:08 +0000
          Re: Java Checked Exception is BAD! Lew <lewbloch@gmail.com> - 2016-02-04 16:09 -0800
  Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-04 12:00 -0500
  Re: Java Checked Exception is BAD! Marcel Mueller <news.5.maazl@spamgourmet.org> - 2016-02-04 19:28 +0100
    Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 11:15 -0800
      Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-04 14:51 -0500
  Re: Java Checked Exception is BAD! 4ndre4 <4ndre4@4ndre4.com.invalid> - 2016-02-04 21:07 +0000
    Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 14:36 -0800
      Re: Java Checked Exception is BAD! a.laforgia@gmail.com - 2016-02-05 05:28 -0800
  Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 15:31 -0800
    Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-05 08:20 -0500
      Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-05 08:25 -0800
        Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-05 08:47 -0800
          Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-05 16:09 -0800
            Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-06 08:38 -0500
              Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-06 14:13 +0000
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-06 15:23 +0100
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-07 14:49 +0100
                Re: Java Checked Exceptions Robert Klemme <shortcutter@googlemail.com> - 2016-02-07 21:55 +0100
                Re: Java Checked Exceptions boxzou@gmail.com - 2016-02-07 14:39 -0800
                Re: Java Checked Exceptions Robert Klemme <shortcutter@googlemail.com> - 2016-02-08 13:30 +0100
                Re: Java Checked Exceptions boxzou@gmail.com - 2016-02-08 06:14 -0800
                Re: Java Checked Exceptions Robert Klemme <shortcutter@googlemail.com> - 2016-02-08 20:55 +0100
                Re: Java Checked Exceptions Lew <lewbloch@gmail.com> - 2016-02-08 16:06 -0800
                Re: Java Checked Exceptions boxzou@gmail.com - 2016-02-08 18:38 -0800
                Re: Java Checked Exceptions Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-09 12:15 +0000
                Re: Java Checked Exceptions boxzou@gmail.com - 2016-02-09 04:59 -0800
                Re: Java Checked Exceptions Lew <lewbloch@gmail.com> - 2016-02-10 12:13 -0800
                Re: Java Checked Exceptions boxzou@gmail.com - 2016-02-10 19:00 -0800
                Re: Java Checked Exceptions Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-11 12:18 +0000
                Re: Java Checked Exceptions leif.roar@dimnakorr.com - 2016-02-11 04:43 -0600
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 14:34 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 14:11 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-07 23:19 +0000
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 15:42 -0800
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-06 09:43 -0500
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 14:14 -0800
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-08 09:22 -0500
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 11:01 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 11:08 -0800
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-08 22:02 +0100
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 14:09 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-07 23:29 +0000
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-08 21:49 +0100
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-08 17:23 -0500
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 18:46 -0800
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-09 08:21 +0100
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-09 04:58 -0800
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-09 08:17 -0500
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-09 07:57 -0800
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-10 02:37 +0100
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-10 18:58 -0800
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-11 08:13 -0500
                Re: Java Checked Exception is BAD! Lew <lewbloch@gmail.com> - 2016-02-11 14:02 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-11 16:41 -0800
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-10 02:31 +0100
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-10 18:47 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-09 12:26 +0000
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-09 04:57 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-09 18:27 +0000
              Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 20:19 -0800
            Re: Java Checked Exception is BAD! Robert Klemme <shortcutter@googlemail.com> - 2016-02-06 16:01 +0100
              Re: Java Checked Exception is BAD! 4ndre4 <4ndre4@4ndre4.com.invalid> - 2016-02-06 15:10 +0000
                Re: Java Checked Exception is BAD! Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2016-02-06 17:59 -0800
                Re: Java Checked Exception is BAD! 4ndre4 <4ndre4@4ndre4.com.invalid> - 2016-02-07 09:34 +0000
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 14:23 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 20:52 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 21:13 -0800
              Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-07 14:19 -0800
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-07 23:42 +0000
                Re: Java Checked Exception is BAD! Robert Klemme <shortcutter@googlemail.com> - 2016-02-08 13:17 +0100
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 04:39 -0800
                Re: Java Checked Exception is BAD! Lew <lewbloch@gmail.com> - 2016-02-08 16:05 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 18:35 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 19:10 -0800
                Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-08 19:12 -0800
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-11 16:37 +0100
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-11 12:00 -0500
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-11 19:01 +0100
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-11 20:32 +0100
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-11 15:20 -0500
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-11 23:53 +0100
                Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-11 18:21 -0500
                Re: Java Checked Exception is BAD! Lew <lewbloch@gmail.com> - 2016-02-11 15:45 -0800
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-12 01:19 +0100
                Re: Java Checked Exception is BAD! Lew <lewbloch@gmail.com> - 2016-02-11 19:18 -0800
                Re: Java Checked Exception is BAD! Sebastian <news@seyweiler.dyndns.org> - 2016-02-12 08:31 +0100
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-12 15:33 +0100
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-12 15:41 +0100
                Re: Java Checked Exception is BAD! Silvio <silvio@internet.com> - 2016-02-12 15:42 +0100
                Re: Java Checked Exception is BAD! Martin Gregorie <martin@address-in-sig.invalid> - 2016-02-08 21:19 +0000
        Re: Java Checked Exception is BAD! Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-02-05 13:00 -0500
  Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 15:51 -0800
    Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 15:59 -0800
      Re: Java Checked Exception is BAD! boxzou@gmail.com - 2016-02-04 16:03 -0800
    Re: Java Checked Exception is BAD! Eric Douglas <e.d.programmer@gmail.com> - 2016-02-05 05:33 -0800
  Re: Java Checked Exception is BAD! Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2016-02-04 21:05 -0800
  Re: Java Checked Exception is BAD! ynseo <yeori.seo@gmail.com> - 2016-02-08 01:05 -0800
  Re: Java Checked Exception is BAD! Sebastian <sebastian.millies@softwareag.com> - 2016-02-19 03:43 -0800

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