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So I looked for a laptop. It needed to be portable, reasonably powerful and < $1000. I looked at Dell first but wasn’t happy with their offerings. After upgrading the OS to Vista Home Premium, getting a decent cpu and upgrading the mem to what Vista needed I was over budget. I also wanted it to be small and portable. No dice. Other brands were the same story. After a while I checked Apple’s page. Macbook, 13″, decent specs… okay how much. 1000 for students & you get a free nano? (Which you can sell of course). Nice! So I got it. I’ve never owned a Mac. After years of bashing the one button mouse, the weird windowing, the non windows-ness of it… I got a mac.

Its nice.

Seriously. Some things take getting used to and all the key bindings are at least slightly different but it’s nice and I’m getting used to it. I’ll post something going feature by feature later. In the meantime I’ll bask in the geek joy of having the top 3 OS’s in my apartment.

C:\Working\Projects\sql_runner\package>jar cvfm fixer.jar .
java.io.FileNotFoundException: . (Access is denied)
        at java.io.FileInputStream.open(Native Method)
        at java.io.FileInputStream.(FileInputStream.java:106)
        at java.io.FileInputStream.(FileInputStream.java:66)
        at sun.tools.jar.Main.run(Main.java:123)
        at sun.tools.jar.Main.main(Main.java:904)

I got a FileNotFoundException on the current directory (“.”). How the hell could it not find the directory I’m in? Oh, there we go… access is denied. Denied? I own the damn folder and I’m an admin. How could access be denied? I’m just trying to jar the current directory.

Well, those were the first thoughts to run through my head. After a couple minutes staring at it and checking permissions on the directory I realized what I did wrong. The real problem was the options I passed into the jar tool. I passed cvfm instead pf cvf. The m means the next argument is expected to be the manifest file. So what it was really saying was it was trying to open “.” as a file and not as a directory. When it couldn’t do that the tool blew up in an unhelpful way. A message saying something along the lines of “Unable to use manifest (‘.’). Specified manifest file is a directory.”. That would’ve been much more helpful. Something to keep in mind for my projects.

Starting the scary items is basic flow and organization of programs. What to name things, factoring out common operations, how to iterate through collections and even what collections to use. I’ve had to clean up code disturbingly similar to the below in several places. Its as if he follows a bad template he saw online somewhere without understanding.

void foo(int x){
    List list = (ArrayList) getValues();
    MyClass realItem = null;

    if(list != null){
        for(int i = 0; i < list.size(); i++){
            MyClass item = (MyClass) list.get(i);

            if( item.getKey() == x ){
                realItem = item;
                break;
            }
        }
    }

    // Do some work using realItem
}

Collection getValues(){
    ArrayList list = new ArrayList();

    Collection allValues = frumple().getAll();
    for( Iterator i = allValues.iterator(); i.hasNext() ) {
        MyClass temp = (MyClass) i.next();
        if(temp.isActive()){
            list.add(temp);
        }
    }
    return list;
}

This guy (call him Joey to protect the guilty) doesn’t see anything wrong with this. I pointed out the following items and Joey just looked at me like, well, sure I could do it that way but theres no real difference between the two…

• Parameters are named with x or value or ambiguous names like id in cases where there are multiple id types available. I’ve told him to specify what kind of id is it. int x as a parameter isn’t very far from the truth.
• He coded getValues() to return a Collection then casts it to an ArrayList. The two methods are in the same class. Absolutely no reason to do this. While I applaud returning a Collection over a List or ArrayList where possible if you’re going to cast it later anyway it’s just stupid.
• Joey checks to see if the list is null even though it can never be null.
• Since the whole point of getValues is just to return a list so he can find a value, why not change getValues to getValueFromField(int field)
• He doesn’t need a list to go through the list… he could’ve done it like he did with the iterator in getValues… why he iterates two different ways is beyond me. Maybe he read somewhere that it’s faster to iterate through an ArrayList that way but this list has at most 20 items. And it’s called very rarely. And the ArrayList is built for every call, offsetting any slight gains made by iterating that way.
• Joey doesn’t bother checking to see if realItem is null after the search even though it could be!. Why not??

Sigh. The rewritten code is shorter is almost every case, much more readable and less error prone.