Java Anonymous Classes
Description
An anonymous class is a class without a name and simultaneously declared. You can instantiate an anonymous class where it is legal to specify an expression.
An anonymous class instance can only access local final variables and final parameters.
Syntax
How to define an anonymous class?
abstract class People {
abstract void speak();
}/* w ww. ja va 2 s . com*/
public class Main {
public static void main(final String[] args) {
new People() {
String msg = "test";
@Override
void speak() {
System.out.println(msg);
}
}.speak();
}
}
The code above generates the following result.
Example
The following code declares and instantiates an anonymous class that implements an interface.
interface People {
abstract void speak();
}/* w w w .j ava 2 s . c o m*/
public class Main {
public static void main(final String[] args) {
new People() {
String msg = (args.length == 1) ? args[0] : "nothing to say";
@Override
public void speak() {
System.out.println(msg);
}
}.speak();
}
}
The code above generates the following result.
