You asked: What is marker interface in Java and examples?

What is Java marker interface?

A marker interface is an interface that has no methods or constants inside it. It provides run-time type information about objects, so the compiler and JVM have additional information about the object. A marker interface is also called a tagging interface.

Why do we use marker interface in Java?

Marker interface is used as a tag to inform a message to the Java compiler so that it can add special behaviour to the class implementing it. … When a Java class is to be serialized, you should intimate the Java compiler in some way that there is a possibility of serializing this java class.

Is comparable a marker interface?

Since Comparable<T> has one method then it is not used as a marker interface. A marker interface is useful when you want to attach data to a type to be able to use this data in specific situations, this is not the case of Comparable , which is used to provide an effective interface.

Is Externalizable a marker interface?

The externalizable interface is not a marker interface and thus it defines two methods writeExternal() and readExternal(). Serializable interface passes the responsibility of serialization to JVM and the programmer has no control over serialization, and it is a default algorithm.

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What is Externalizable interface in Java?

Externalization serves the purpose of custom Serialization, where we can decide what to store in stream. Externalizable interface present in java.io, is used for Externalization which extends Serializable interface. It consist of two methods which we have to override to write/read object into/from stream which are-

Can we write marker interface Java?

You can write your own Marker interface ,JVM do not know anything about it. A marker interface is an empty interface. This mean you just need to create a interface and do not create any method in it.

What is the use of empty interface in Java?

Empty interfaces are used to mark the class, at run time type check can be performed using the interfaces. For example An application of marker interfaces from the Java programming language is the Serializable interface.

What is advantage of serialization in Java?

Serialization allows us to transfer objects through a network by converting it into a byte stream. It also helps in preserving the state of the object. Deserialization requires less time to create an object than an actual object created from a class. hence serialization saves time.

What is true serialization?

Serialization provides a way where an object can be represented as a sequence of bytes which includes the object’s data and information having the object’s type and the types of data stored in the object. It can only be read from the file after the serialized object is written into a file.