Hi friend,


* In general tagged or marker interface is used to just identify the class, in real time projects there are so many classes,in order to identify which class belongs to which module,this tag or marker interface is useful.

*. In serialization also,if we want to serialize the object,first it will internally checks whether the class is implementing java.io.serializable interface by using instanceof operator.

* In rmi also every remote class should implement java.rmi.remote interface.

Here is simple example:

public interface roseDemo{

}
public class computer implements roseDemo{
int no;
String name;
}

public class Sample {
computer com =new computer();

if(com instanceof roseDemo) {
com.name="Welcome to roseindia";

}
}

-------------------------------------------------------

Visit for more information:

http://www.roseindia.net/java/master-java/interface.shtml

Thanks