JAVA TUTORIALS FOR BEGINNER: static block

<div class="content clearfix">
 <div class="field field-name-body field-type-text-with-summary field-label-hidden">
<div class="field-items">
<div class="field-item even">
Java
 programming language offers a block known as static which is executed 
before main method executes. Below is the simplest example to understand
 functioning of static block later we see a practical use of static 
block.

<h2>
Java static block program</h2>
<div class="geshifilter">
<pre class="java geshifilter-java" style="font-family: monospace;">class StaticBlock {
 public static void main(String[] args) {
 System.out.println("Main method is executed.");
 }
 
 static {
 System.out.println("Static block is executed before main method.");
 }
}</pre>
</div>
Output  
 
 
<img alt="Java static block program" src="http://www.programmingsimplified.com/images/java/java-static-block-program.png" />

Static block can be used to check conditions before execution of main
 begin, Suppose we have developed an application which runs only on 
Windows operating system then we need to check what operating system is 
installed on user machine. In our java code we check what operating 
system user is using if user is using operating system other than 
"Windows" then the program terminates.

<div class="geshifilter">
<pre class="java geshifilter-java" style="font-family: monospace;"> </pre>
<pre class="java geshifilter-java" style="font-family: monospace;"> </pre>
<pre class="java geshifilter-java" style="font-family: monospace;">class StaticBlock {
 public static void main(String[] args) {
 System.out.println("You are using Windows_NT operating system.");
 }
 
 static {
 String os = System.getenv("OS");
 if (os.equals("Windows_NT") != true) {
 System.exit(1);
 }
 }
}</pre>
</div>
 
We are using getenv method of System class which returns value of 
environment variable name of which is passed an as argument to it. 
Windows_NT is a family of operating systems which includes Windows XP, 
Vista, 7, 8 and others.

Output 
 
<img alt="Java static block program" src="http://www.programmingsimplified.com/images/java/java-static-block-program-2.png" />

</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>

Java static block program

Java programming language offers a block known as static which is executed before main method execute...

JAVA TUTORIALS FOR BEGINNER

Populars

MKRdezign

About Me

Archive

Breaking News

Java static block program