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

Joe Darcy joe.darcy at oracle.com
Mon Aug 8 17:04:54 UTC 2011

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 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; }

More information about the core-libs-dev mailing list