CertPal

Gmail, google’s popular email service took an outage today. If you want to get a hint of what kind of impact that can make, check out google trends . The top 5 search terms are about gmail being down

Google trends:

I am sure some posts will crop up with something negative to say. But show me an email service that uses ajax, tags your emails, provides chatting integrated with the browser, (oh ! I could go on) and is so reliable. When was the last time you heard about a gmail outage ? Some of the best services out there are not as reliable as the free gmail.

Google’s SLA was also broken due to the down time, which seems to have spanned about 2-3 hours. If rumors are to be believed, google is offering a 15 day service chargeback to its paying customers instead of a 3 day service chargeback that the SLA covers. That would work out to around 2$. Gmail labs also provides an offline service, so not all users may have been affected.

Eclipse is a pretty good IDE to develop java apps on. However there are some features that you might not be using every day that can save you a lot of time.

Writing your own code templates is one of them. To write your own code template do the following

Go to Window -> Preferences. Select Java -> Editor -> Templates. You can add your own templates here. Templates are nothing but the code that auto completes when you press ctrl+space. For example type syso and ctrl+space. This will automatically fill in System.out.println() into the editor.

Eclipse code templates:

Code template variables:

Eclipse can automatically fill out dynamic code by sniffing out variables in a template. Here are a few you should make yourself aware of

Which of these tools do you use to code in java ? I use myeclipse for J2EE coding and Netbeans for swing UI (which I would highly recommend.). I have worked with workshop as well.

 Loading ...

Java allows you to add shutdown hooks to your code. A shutdown hook is simply a thread that has been left in the initialized state. When your JVM is about to shutdown, the shutdown hook thread kicks in. The finalization processes of java objects run after the shutdown hooks complete. The JVM allows you to register more than one shutdown hook.

Let us take a look at how this is done

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

public class Task
{
    public static void main(String[] args)
    {
        Runtime runtime = Runtime.getRuntime();
        Thread thread = new Thread(new ShutDownListener());
        runtime.addShutdownHook(thread);
        someProcess();
    }
 
    private static void someProcess()
    {
        try
        {
            System.out.println("I am busy");
            Thread.sleep(2000);
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }
    }
}
 
class ShutDownListener implements Runnable
{
    @Override
    public void run()
    {
        System.out.println("I am shutting down");
    }
}

The Task class is a simple class that runs a process. Once this process finishes up, we want the JVM to run a shutdown hook to notify us that the JVM is shutting down. When this program is run, the output is

1
2

I am busy
I am shutting down

Nice !

Lets experiment a little more. How robust is a shutdown hook ? After the someProcess() method is called let us analyze what will happen when one of the following statements are added

Here are 5 free UML modelling tools you can use. I use the JUDE community version. I found the user interface easy to learn and the product was also feature rich and simple. The products are not necessarily arranged in any specific order and the list is certainly not exhaustive.

Have fun designing

JUDE – community: http://jude.change-vision.com/jude-web/product/community.html

UMLet: http://www.umlet.com/

Argo UML: http://argouml.tigris.org/

BOUml: http://bouml.free.fr/download.html

Visual paradigm – community: http://www.visual-paradigm.com/product/vpuml/editions/community.jsp