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

[Sebastian Sickelmann]

Looks good to me.

But i have one question:
    Why there are two ways to plumb the causes of an exception?
    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?

- 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;
    }