ANONYMOUS INNER CLASSES IN JAVA
Inner classes concept in java is one of the most important concept in java programming.It is not a new concept in java.but most of programmers not that much comfortable in inner classes concept.
So basically anonymous inner class is a class which does not have any name, yes without name. It is mostly used in the instantly purpose.If our requirement is just use the code only ones and not use that anymore than we should go for anonymous inner classes.
syntax:
{
};
Example:
Without anonymous class approch:
Take a class Icecream and a method test. if you are not satisfy with test then override the test function according to your requirement.
class Icecream
{
public void test()
{
System.out.println("stobarry");
}
}
class Desert extends Icecream
{
public void item()
{
System.out.println("vanila");
}
public static void main(String[] args)
{
Desert t=new Desert();
t.item();
}
}
output:
Vanila
With anonymous inner class aproch:
class Icecream
{
publi
System.out.println("stobarry");
}
public static void main(String[] args)
{
Icecream i=new Icecream()
{
public void test()
{
System.out.println("choclate");
}
};
i.test();
}
}
output:
choclate
There are three types of anonymous inner classes:
1. Anonymous inner class which extends a class
2. Anonymous inner class which implements an interface
3. Anonymous inner class inside arguments.
1. Anonymous inner class which extends a class:
Example:
class AnonymousDemo
{
public static void main(String[] args)
{
Thread t=new Thread()
{
public void run()
{
for(int i=0;i<10;i++)
{
System.out.println("child thread");
}
}
};
t.start();
for(int i=0;i<10;i++)
{
System.out.println("main thread");
}
}
}
output:
main thread
main thread
main thread
main thread
main thread
main thread
main thread
main thread
main thread
main thread
child thread
child thread
child thread
child thread
child thread
child thread
child thread
child thread
child thread
child thread
2. Anonymous inner class which implements an interface
class AnonymousDemo
{
public static void main(String[] args)
{
Runnable r=new Runnable()
{
public void run()
{
for(int i=0;i<10;i++)
{
System.out.println("child thread-1");
}
}
};
Thread t=new Thread(r);
t.start();
for(int i=0;i<10;i++)
{
System.out.println("main thread-1");
}
}
}
output:
main thread-1
main thread-1
main thread-1
main thread-1
main thread-1
main thread-1
main thread-1
main thread-1
main thread-1
main thread-1
child thread-1
child thread-1
child thread-1
child thread-1
child thread-1
child thread-1
child thread-1
child thread-1
child thread-1
child thread-1
3. Anonymous inner class inside arguments
class AnonymousDemo
{
public static void main(String[] args)
{
new Thread(new Runnable()
{
public void run()
{
for(int i=0;i<10;i++)
{
System.out.println("child");
}
}
}).start();
for(int i=0;i<10;i++)
{
System.out.println("main");
}
}
}
output:
main
main
main
main
main
main
main
main
main
main
child
child
child
child
child
child
child
child
child
child
