Java Instrumentation - knowing your JVM

If rape becomes inevitable ... enjoy it.
-S

Will Oracle kill Java Community

I spent my few hours going through various forums and reading about the after effects of the one of the biggest mergers in software industry, Oracle's acquisition of Sun. There were concerns which made me think too.

1. Will MySQL die ?
   Being Database giant will Oracle support MySQL or silently kill it. The database market is currently ruled by three major companies - IBM, Microsoft and Oracle - controlling 85 per cent of the market in revenue terms and Sun's MySQL (free and open source) will extend further into Oracle's market as its functionality improves. So why will Oracle support it?
   
   
2. Future of GlassFish ?
   Will GlassFish become extinct? Oracle already sells WebLogic (after it acquired BEA Systems) and Oracle Application Server. Oracle may say no to support GlassFish project as it already has to support two identical application servers.
   
   
3. What will happen to NetBeans?
   Oracle is a strong supporter of Eclipse so NetBeans might die with time as well.
   

Oracle has to get everyone together as soon as possible to spell out their future plans for Java Community. If Oracle doesn’t, they’ll have Java developers running, not walking, away from the Sun/Oracle Java as fast as they can.

The fate of language depends on how many people respond back to its "Hello World"
-S

Dating with JAVA

Programatically in JAVA a Date object is nothing but a long value that holds the number of milliseconds since January 1, 1970, 00:00:00 GMT.
So new Date() on Aug 14 13:53:58 EST 2008 would be the same as Aug 14 10:53:58 PST 2008 = 1218740038000 (precise to the last 3 digits).

So how are those two different? TimeZoneOffset.
This is an int value that gives millisecs difference between GMT and the Specified TimeZone.
So When printing/displaying or getting the value of date in TimeZone, this timezone offset is added to the long utc secs.

This gives the new print value (or display value - Aug 14 13:53:58 EST 2008 ).
The display value includes all calculations for Timezone and is meaningfully correct only when displayed with the Timezone information (as above).
Just reading and writing "yyyy-MM-dd hh:mm:ss" is incorrect.


A count of the number of milliseconds since the standard base time known as "The Epoch", namely January 1, 1970, 00:00:00 GMT as stated above.

You cannot convert a Date into a different time zone, but you can use Java's  DateFormat class to format a Date into the time zone you want.

Simplifying it , let Date do what it does and when you're ready to display or print out a String representation of Date, that's when you tell DateFormat what time zone you want it in.

So, here's some code that shows it:

final Date currentTime = new Date();

final SimpleDateFormat sdf =
        new SimpleDateFormat("EEE, MMM d, yyyy hh:mm:ss a z");

// Give it to me in US-Pacific time.
sdf.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles"));
System.out.println("LA time: " + sdf.format(currentTime));

Dating without a Date. -S