What is volatile and transient keyword in Java?

What is volatile keyword in Java?

Volatile keyword is used to modify the value of a variable by different threads. … It means that multiple threads can use a method and instance of the classes at the same time without any problem. The volatile keyword can be used either with primitive type or objects.

What is difference between volatile and transient?

In this article, we will see the difference between the keywords volatile and transient.


Transient Volatile
It cannot be used with the static keyword as static variable do not belong to individual instance. During serialization, only object’s current state is concerned. It can be used with the static keyword.

What is transient in Java example?

transient variable in Java is a variable whose value is not serialized during Serialization and which is initialized by its default value during de-serialization, for example for object transient variable it would be null.

What is volatile keyword used for?

The volatile keyword prevents the compiler from performing optimization on code involving volatile objects, thus ensuring that each volatile variable assignment and read has a corresponding memory access.

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What is transient variable in Java?

A transient variable is a variable that can not be serialized. According to Java Language Specification [jls-8.3. 1.3] – “Variables may be marked transient to indicate that they are not part of the persistent state of an object.”

What is difference between volatile and atomic variables Java?

Volatile and Atomic are two different concepts. Volatile ensures, that a certain, expected (memory) state is true across different threads, while Atomics ensure that operation on variables are performed atomically.

How does volatile work in Java?

Since volatile keyword in Java only synchronizes the value of one variable between Thread memory and “ main ” memory while synchronized synchronizes the value of all variable between thread memory and “ main ” memory and locks and releases a monitor to boot.

What is serializing and Deserializing?

Serialization is a mechanism of converting the state of an object into a byte stream. Deserialization is the reverse process where the byte stream is used to recreate the actual Java object in memory.

Can volatile variable be serialized?

2 Answers. A volatile is typically serialized by Java Object Serialization. The threading / JMM properties of volatile are orthogonal to serialization. Incidentally, it is possible to serialize a transient or static variable, if you code custom writeObject / readObject methods to do this.

What is transient keyword?

transient is a variables modifier used in serialization. At the time of serialization, if we don’t want to save value of a particular variable in a file, then we use transient keyword. When JVM comes across transient keyword, it ignores original value of the variable and save default value of that variable data type.

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Can an integer be transient?

In the code below, we have created a Member class object with a transient int id and a simple String name . Since the id is transient,​ it cannot be written in the file, so ​ 0 is stored instead. transient int id; // This will not serialized.

What is a transient value?

A transient value is a wrapper around a value allocated by a disposable that allows users of the value to have some limited control over its lifecycle. In particular, users of a transient may: Eagerly dispose the value with transient-dispose.

How do you use volatile?

A volatile keyword in C is nothing but a qualifier that is used by the programmer when they declare a variable in source code. It is used to inform the compiler that the variable value can be changed any time without any task given by the source code. Volatile is usually applied to a variable when we are declaring it.

Can we make array volatile in Java?

Can we make an array volatile in Java? … The answer is, Yes, you can make an array (both primitive and reference type array e.g. an int array and String array) volatile in Java but only changes to reference pointing to an array will be visible to all threads, not the whole array.

Where are volatile variables stored in Java?

Volatile fields are instance or class (static) variables and are stored in the heap.