JDK 8 code review request for 6380161 (reflect) Exception from newInstance() not chained to cause.

[Sebastian Sickelmann]

Thanks for encouraging me.

I opened a bug [1] at bugs.openjdk.java.net. Hope that is a right first 
step to getting started.
I wanted to investigate the calls to initCause in jdk-source first to 
pick the most valueable Exceptions first.
I thinks there are many exceptions out of scope of core-libs. How to 
handle these ones. I think i will
start with exceptions from core-libs.
Is there a pattern that says me exceptions belongs to which openjdk-project?

- Sebastian

[1] https://bugs.openjdk.java.net/show_bug.cgi?id=100201

Am 08.08.2011 19:04, schrieb Joe Darcy:
> Hello.
>
> On 8/8/2011 7:24 AM, Sebastian Sickelmann wrote:
>> Looks good to me.
>>
>> But i have one question:
>>
>>     Why there are two ways to plumb the causes of an exception?
>
> The history of this situation is covered in older versions of the 
> javadoc of Throwable:
> http://download.oracle.com/javase/6/docs/api/java/lang/Throwable.html
>
>>     In many exceptions-classes you can use a constuctor-level 
>> argument to specify the cause, and in some classes you must use the 
>> initCause method.
>>
>>     Is it: "When you often need a cause at creation-time than we got 
>> a specializes constructor." ?
>>
>>     I found 500+ lines jdk/src/share/classes/**/*.java where i found 
>> line like
>>
>>            XYZException iae = new XYZException();
>>             iae.initCause(e);
>>             throw iae;
>>
>>     I am searching a minor project for my second Contribution to 
>> OpenJDK to learn more about the developement / review process.
>>     Is it worthwhile to look at this issue and maybe refactor some of 
>> the often used Exceptions to accept a cause at construction-time?
>
> I would say such a project would be helpful; for context, this topic 
> came up a few months ago on core-libs in the context of another code 
> review:
>
>     
> http://mail.openjdk.java.net/pipermail/core-libs-dev/2011-June/007005.html
>     
> http://mail.openjdk.java.net/pipermail/core-libs-dev/2011-June/007008.html
>
> Cheers,
>
> -Joe
>
>>
>> - Sebastian
>>
>> Am 08.08.2011 07:24, schrieb Joe Darcy:
>>> Hello.
>>>
>>> Please review this small fix, developed after I went through my open 
>>> bug list; patch below, webrev at:
>>>
>>>    6380161 (reflect) Exception from newInstance() not chained to cause.
>>>    http://cr.openjdk.java.net/~darcy/6380161.0/
>>>
>>> Several call to initCause are added to plumb up caused-by exception 
>>> chains to exception types without constructors taking a cause.  In 
>>> addition, multi-catch is added in on location.
>>>
>>> I looked for similar issues in Constructor, Method, and Executable, 
>>> but there weren't any.
>>>
>>> Thanks,
>>>
>>> -Joe
>>>
>>> --- old/src/share/classes/java/lang/Class.java    2011-08-07 
>>> 22:21:58.000000000 -0700
>>> +++ new/src/share/classes/java/lang/Class.java    2011-08-07 
>>> 22:21:58.000000000 -0700
>>> @@ -349,7 +349,8 @@
>>>                         });
>>>                 cachedConstructor = c;
>>>             } catch (NoSuchMethodException e) {
>>> -                throw new InstantiationException(getName());
>>> +                throw (InstantiationException)
>>> +                    new 
>>> InstantiationException(getName()).initCause(e);
>>>             }
>>>         }
>>>         Constructor<T> tmpConstructor = cachedConstructor;
>>> @@ -973,7 +974,8 @@
>>>                 descriptor      = (String)   enclosingInfo[2];
>>>                 assert((name != null && descriptor != null) || name 
>>> == descriptor);
>>>             } catch (ClassCastException cce) {
>>> -                throw new InternalError("Invalid type in enclosing 
>>> method information");
>>> +                throw (InternalError)
>>> +                    new InternalError("Invalid type in enclosing 
>>> method information").initCause(cce);
>>>             }
>>>         }
>>>
>>> @@ -1239,7 +1241,8 @@
>>>         try {
>>>             return 
>>> getName().substring(enclosingClass.getName().length());
>>>         } catch (IndexOutOfBoundsException ex) {
>>> -            throw new InternalError("Malformed class name");
>>> +            throw (InternalError)
>>> +                new InternalError("Malformed class 
>>> name").initCause(ex);
>>>         }
>>>     }
>>>
>>> @@ -2954,9 +2957,8 @@
>>>             }
>>>             // These can happen when users concoct enum-like classes
>>>             // that don't comply with the enum spec.
>>> -            catch (InvocationTargetException ex) { return null; }
>>> -            catch (NoSuchMethodException ex) { return null; }
>>> -            catch (IllegalAccessException ex) { return null; }
>>> +            catch (InvocationTargetException | NoSuchMethodException |
>>> +                   IllegalAccessException ex) { return null; }
>>>         }
>>>         return enumConstants;
>>>     }
>>>
>>
>