Steven Yong's Weblog

CVS and Subversion are two of the most popular source code control utilities, thousands of open source projects are using these two software to host their source code. Therefore, it is always worth remembering some useful commands such as checking out and updating source modules.

For CVS:

To check out: cvs -d<CVS Root> login followed by cvs -d<CVS Root> -P <Module Name>
Example, check out source code of Mozilla
- cvs -d:pserver:anonymous@cvs-mirror.mozilla.org:/cvsroot login
- Enter password when prompted
- cvs -d:pserver:anonymous@cvs-mirror.mozilla.org:/cvsroot co -P mozilla

To update latest code: cvs update

For SVN:

To check out: svn co <SVN Path>
Example, check out source code of Apache Tomcat Server
svn co http://svn.apache.org/repos/asf/tomcat/trunk

To update latest code: svn update

When in need, it will come in handy.

I did not expect that it would take me 2 years just to upgrade my blog system.
Anyway, finally I got it done, from version 0.9 to 1.3. So what are the new things that you, as a reader will see?

Nothing much actually.

There is lots more styles for you to choose and I believe it would load faster

It seems a little boring by telling you that this blog system has got upgraded, let me see... why not share with you the successful page after the system upgrading is done?

I think what really has to be upgraded is the frequency of my posting, don't you agree?

PS: Sorry for make you waiting Angie.

Let's say we have an enumerated type Result:

enum Result { Pass, Fail }

When we do a print of either type, like:System.out.println(Result.Pass) we get a word "Pass" which is not so user-friendly.
There are many ways to add a label to each enumeration and here are three common ones:

enum Result {
    Pass, Fail;

    String getLabel() { 
        switch(this) {
            case Pass : return "You are passed";
            case Fail : return "You are failed";
        }
        throw new AssertionError("Unknown result: " + this);
    }
}

enum Result {
    Pass("You are passed"), Fail("You are failed");
    
    Result(String s) { label = s; }
    
    String label;
    
    String getLabel() { return label; }
}

enum Result {
    Pass { String getLabel() { return "You are passed"; }},
    Fail { String getLabel() { return "You are failed"; }};

    abstract String getLabel();
}

All of them print "You are passed" when displaying Result.Pass.getLabel(). I believe the first approach is relatively slower since it needs to do checking, although it is cleaner at the type definition. Second approach make use of constructor but an instance variable has to be introduced, it's also not so extensible since it would end up with a few constructors when more aliases are required. I prefer the last approach as it looks more flexible.

Let's don't talk about the practical usage, isn't it cool to have a computer running inside a pen with a reasonable price of $149 (1GB) and $199 (2GB)?

Check out the Live demo at JavaOne (fast forward to 58th minute) and the company website. Guess what's the problem that this pen is trying to solve? See what tagline they've trademarked.