Playing with JVM / Java Heap Size.

Java programs executes in JVM uses Heap of memory to manage the data. If your Java program requires a large amount of memory, it is possible that the virtual machine will begin to throw OutOfMemoryError instances when attempting to instantiate an object. The default heap size if 1 MB and can increase as much as 16 MB.

Setting/Increase JVM heap size

It is possible to increase heap size allocated by the Java Virtual Machine (JVM) by using command line options.
Following are few options available to change Heap Size.

1. -Xms<size> set initial Java heap size
2. -Xmx<size> set maximum Java heap size
3. -Xss<size> set java thread stack size

For example, you can set minimum heap to 64 MB and maximum heap 256 MB for a Java program HelloWorld.

1. java -Xms64m -Xmx256m HelloWorld

Getting / Reading default heap size

It is possible to read the default JVM heap size programmatically by using totalMemory() method of Runtime class. Use following code to read JVM heap size.

public class GetHeapSize {

public static void main(String[]args){

//Get the jvm heap size.

long heapSize = Runtime.getRuntime().totalMemory();

//Print the jvm heap size.

System.out.println("Heap Size = " + heapSize);

}

}

How to show each post’s date in WordPress

The templating system in WordPress is very flexible, and there's  rarely something you can't do or that doesn't work as you'd expect. A  notable exception however is the_date.  Its purpose is simple enough. It displays the current post's date of  creation. But on pages with more than one post (such as on many blog  home pages), something weird happens. If a number of posts on any given  page were created on the same date, the_date will only show  that date for the first of those posts.

In the early days of blogging, posts were usually listed by date,  much like a regular, paper diary. In the old default theme that comes  with WordPress a big date title is used to separate posts into days.  That's what the_date was created to do, and so it makes  sense it only displays the same date once. In most modern themes  however, people like the date to be among the meta data for each  article, so the_date falls short.

ChromeOS gets more mature with Flow

It's been a while since I blogged about Chrome OS. Things have been pretty quiet around the Google-supported operating system for netbooks and tablets. But Hexxeh, a 17^th year old developer who's been supplying pre-built versions of the OS for a while now, released an new version yesterday, and it's a lot more polished than earlier builds. It boots in seconds and runs pretty smoothly for a pre-alpha OS. If you're curious about Chrome OS, this is the perfect opportunity to give it a try.

Not only is the 'Flow' build very easy to use, there are complete setup instructions as well. The OS is installed on a USB stick or an SD card (provided your target computer has a card reader it can boot from). It runs off of that drive, so nothing is left behind on the computer's hard drive. Simply take out the SD card and boot up to get back to Windows or whatever you were using before.