Exceptions from calling Java

[Ikarius]

Okay, I've got more exceptions than this, but I figured I'd start with this one, and see what falls out of this. I'm currently doing a bunch of work altering some STVi's, and some of what I'm doing is calling straight java from the Studio interface. It appears that this is throwing some exceptions, even though the routines appear to be doing what I expect. Here's the debug output of an exception:

Sun 2/22 17:30:30.467 EXCEPTION in getValueAsObject:sage.a.e: Error in method reflection of java_util_ArrayList_add of java.lang.NullPointerException for:java_util_ArrayList_add( Categories, "NewReleases" )
Sun 2/22 17:30:30.468 sage.a.e: Error in method reflection of java_util_ArrayList_add of java.lang.NullPointerException
Sun 2/22 17:30:30.468 	at sage.e$d.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.a.m$b.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.a.m.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.b1.M(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.UIManager.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.UIManager.a(Unknown Source)
Sun 2/22 17:30:30.468 	at sage.f$23.run(Unknown Source)
Sun 2/22 17:30:30.468 Caused by: java.lang.NullPointerException
Sun 2/22 17:30:30.468 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Sun 2/22 17:30:30.468 	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
Sun 2/22 17:30:30.469 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
Sun 2/22 17:30:30.469 	at java.lang.reflect.Method.invoke(Unknown Source)
Sun 2/22 17:30:30.469 	... 14 more
Sun 2/22 17:30:30.469 java.lang.reflect.InvocationTargetException
Sun 2/22 17:30:30.469 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Sun 2/22 17:30:30.469 	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
Sun 2/22 17:30:30.469 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
Sun 2/22 17:30:30.469 	at java.lang.reflect.Method.invoke(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.e$d.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.a.m$b.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.a.m.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.469 	at sage.b1.M(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.UIManager.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.UIManager.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.f$23.run(Unknown Source)
Sun 2/22 17:30:30.470 Caused by: java.lang.NullPointerException
Sun 2/22 17:30:30.470 	at java.util.Collections.sort(Unknown Source)
Sun 2/22 17:30:30.470 	... 18 more
Sun 2/22 17:30:30.470 java.lang.NullPointerException
Sun 2/22 17:30:30.470 	at java.util.Collections.sort(Unknown Source)
Sun 2/22 17:30:30.470 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Sun 2/22 17:30:30.470 	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
Sun 2/22 17:30:30.470 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
Sun 2/22 17:30:30.470 	at java.lang.reflect.Method.invoke(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.e$d.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.a.m$b.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.a.m.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.a8.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.470 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.471 	at sage.e.a(Unknown Source)
Sun 2/22 17:30:30.471 	at sage.b1.M(Unknown Source)
Sun 2/22 17:30:30.471 	at sage.UIManager.a(Unknown Source)
Sun 2/22 17:30:30.471 	at sage.UIManager.a(Unknown Source)
Sun 2/22 17:30:30.471 	at sage.f$23.run(Unknown Source)

This is coming out of the following Studio code:

Categories = new_java_ArrayList( java_utils_Arrays_asList( GetAllCategories() ) )
java_util_ArrayList_add( Categories, "NewReleases" )

So, am I doing something wrong, is this a bug, or is it expected behavior of the funky auto-typecasting of the Sage API?

Ikarius

[GKusnick]

You should not normally get exceptions when calling Java from Studio code. Turn on Tools > Notify On Errors in Studio to get a popup dialog when an exception occurs.

According to your stack trace, you're getting a NullPointerException in java_util_ArrayList_add, probably because you're passing in a null argument. Sure enough, your Categories variable is not getting initialized properly because you called new_java_ArrayList instead of new_java_util_ArrayList. So presumably there's an "unknown method" error being logged just before the snippet of log you showed us.

If you haven't already done so, I highly recommend enabling SageTV's console window during Studio development. That way you can see the errors as they occur instead of having to dig them out of the log after the fact. If your code goes wrong and throws a bunch of exceptions, it's pretty obvious with the console window open and visible. But wait, you're developing on a Mac, right? In that case I'm afraid I have no idea how to enable the console window (in Windows it's a registry setting) or even if one exists in the Mac version.

[Ikarius]

/sigh.
Lesson learned. When copying code from one workstation to another, you're subject to typos. Also don't call the default sage sort routine on an arraylist, as you're not likely to get an arraylist back, thus later attempts to call "add" will cause exceptions.

God for the ability to use diff, patch, and vi.

[GKusnick]

Originally Posted by Ikarius

God for the ability to use diff, patch, and vi.

Well, there is the built-in UID File Difference and STVI generator command, which can be used to encode differences between two STVs in a form that can be imported into a third STV.

And come to that, STV files are just XML, which is just text. So using text-based diff and patch tools isn't totally out of the question.