static block in Java

which holds piece of code to executed when class is loaded in Java. This is also known as static initialize block as shown in below example.

static {
        String category = "electronic trading system";
        System.out.println("example of static block in java");
    }

Beware that if your static initialize block throws Exception than you may get java.lang.NoClassDefFoundError when you try to access the class which failed to load.