Month: May 2009

After spotting that seemingly 90% of the methods on the Date class were deprecated, I started getting worried.  Then when new Date().getYear() started giving me odd numbers like 109 instead of 2009.  I started thinking “Wow! Those Sun developers must have been on some strong drugs when they designed this language!”

So a bit more googling and some “WTF?!?!!?”’s later I found out that the Date class returns the time since January 1, 1970.  So of course .getYear() returns the number of years since then.  Well, not exactly.  Because there are only 39 years since 1 Jan 1970 and today.  So how the heck did getYear() return 109?  I didn’t bother to go any further than that – clearly the Sun developers were on drugs that should never have been invented, and I didn’t want to even think about starting to try and understand what was going on in their twisted little minds at that point in time.

BUT, I found out that they have a GregorianCalendar class which can help you out in most situations, even if it’s a little obtuse in how you use it.

The following code:

Calendar cal = new GregorianCalendar(mYear, mMonth, mDay, mHour, mMinute, mSecond);

Gives you a calendar object based on the input you gave it.  Now of course I get a Date object from a database so I want to do new GregorianCalendar(mDate).  But again, that would be asking too much, so instead of that simple instantiation I have to do:

Calendar cal = GregorianCalendar.getInstance();
cal.setTime(creationDate);

Why, on earth did they call it setTime?  I mean, I’m setting a date and time.  I’m not just working with Time here folks! Surely the method should be named something a little better like .setDateTime() or .setDate()?

But wait… it gets better.  You know the Date class had a getYear() method, right? Remember? It’s the one that requires large amounts of hallucinogens to understand or use!  Well, naturally you’d expect that the Calendar class would have a getYear() that makes sense.

That’s where you’d be wrong!  Since they started with the obscure requirement of doing .GetInstance() followed by .setTime(mDate), they clearly hadn’t quite yet gotten off their high when they made the get() method.  Here’s how you use it:

Calendar cal = GregorianCalendar.getInstance();
cal.setTime(creationDate);
mYear = cal.get(GregorianCalendar.YEAR);
mMonth = cal.get(GregorianCalendar.MONTH);
mDay = cal.get(GregorianCalendar.DAY_OF_MONTH);

Yup, that’s right… why make it as simple as cal.getYear() when you can make it cal.get(GregorianCalendar.YEAR)?  Perhaps someone over at Sun had some stock in a company that provides treatment for RSI’s, so that by making us type out loads more letters they hoped to make more of us suffer not only the pain of using their language, but also of repetitive stress injuries.

BIG DISCLAIMER:

From my brief work with Java previously, I know that the designers were NOT on any drugs and in fact they probably had very good reason for designing the classes the way that they did. It’s just not immediately obvious to the new user, and that’s mainly what I’m ranting about here.  So, to all the Java fanboys out there who are preparing to unleash their full fury on me for my sacrilegious comments about their language – please take a moment and laugh before you post. 🙂

After bitching about the lack of good tutorials last time, I found that I’d actually been looking at Android 1.1 tutorials and trying to run them on Android 1.5.

Now that 1.5 is out (well, it was released quite a while ago, but I’ve only recently started using it in earnest) I’ve re-read the tutorials and some of the introductory info on the Android Developer’s Guide. In my exploring I’ve hit MANY “Force Close” dialogs.  Unfortunately they never seem to say anything about WHY the app is being forced to close.

The first few times I’ve just popped Eclipse into debug mode in an attempt to figure out what’s wrong.  Unfortunately it doesn’t seem to help much.The exceptions that end up being thrown seem really vague and not entirely related to the issue at hand.  So without any further blabbing, here are my top three reasons for getting a “Force Close” in my Android development:

1. Putting the call to setContentView at the end of the onCreate method instead of the start.

Initially I thought I’d be clever and first setup all my event handlers, and data binding and stuff.  But after some really confusing exceptions I realised that unless I call setContentView at the top of my onCreate, I won’t have access to any of the “objects” on my form.

2. Having an abstact class instead of a concrete class for my Activity

I’m not entirely sure how Eclipse and I came to this point, but somehow when adding this class I must have ticked a box that I hadn’t ticked before and suddenly the class was abstract.  No idea how or why this happened, and I certainly didn’t notice it at the time.

Of course I’d expect the exception to say something about “You cannot create an instance of an abstract class.” or something  meaningful like that.  But no, it seemed that this was not to be.

3. Not adding the Activity to the AndroidManifest.xml

This happened at the same time as the issue in point two so I’m not too sure if the two issues together just made the cause of the problem really hard to find.   Maybe I’m just too used to Visual Studio protecting me from myself, but this seemed a little silly.  I created a class that extends Activity.  Now I still need to go and add that info to the AndroidManifest.xml file?  I

People might think that I’ve been overly coddled by VS.Net, and that this is simply how normal development works.  If I used a Wizard to credit an Invoice, I’d expect to have a credit note created at the end, ready to send on to the client.  I wouldn’t expect to have to then go and specify the Client, and add the information for the line items, and then add up the totals manually and then finally to add on the VAT before I could send it.

There are a few nice wizards to get things started, but they often seem to only go half way. If I use a wizard, I expect the wizard to do the whole job.  So when I add an Activity to an Android app, I’d expect it to create the class AND enter the information into the AndroidManifest.xml file for me. Actually, in this case there is really no Wizard in the SDK toolkit to add the Activity – and that’s another gripe – there are wizards to create an Android XML file which is relatively easy to do.  But something like creating a new Activity requires a bunch of manual steps.  So where’s the consistency?

Anyway – enough whining.  Soon I’ll face the anger of a mob of Java developers. 😉