ThreadFactory Interface in Java with Examples
Last Updated :
15 Jul, 2025
The ThreadFactory interface defined in the java.util.concurrent package is based on the factory design pattern. As its name suggests, it is used to create new threads on demand. Threads can be created in two ways:
1. Creating a class that extends the Thread class and then creating its objects.
Java
import java.io.*;
class GFG {
public static void main(String[] args)
{
// Creating a thread
Thread thread = new CustomThread();
thread.start(); // Starting execution of the created
// thread
}
}
// Creating a class that extends the Thread class
class CustomThread extends Thread {
@Override public void run()
{
System.out.println("This is a thread");
}
}
2. Creating a class that implements the Runnable interface and then using its object to create threads.
Java
/*package whatever //do not write package name here */
import java.io.*;
class GFG {
public static void main(String[] args)
{
// Creating a Runnable object
Runnable task = new Task();
// Creating a thread using the Runnable object
Thread thread = new Thread(task);
// Starting the execution of the created thread
thread.start();
}
}
class Task implements Runnable {
@Override public void run()
{
System.out.println("This is a thread");
}
}
However, ThreadFactory is another choice to create new threads. This interface provides a factory method that creates and returns new threads when called. This factory method takes a Runnable object as an argument and creates a new thread using it.
The Hierarchy of ThreadFactory
java.util.concurrent
↳ Interface ThreadFactory
Implementation of ThreadFactory interface
Since ThreadFactory is an interface, the factory method defined inside it has to be implemented first in order to be used. Here is the simplest implementation of the ThreadFactory interface :
Java
import java.util.concurrent.ThreadFactory;
import java.io.*;
class CustomThreadFactory implements ThreadFactory {
// newThread is a factory method
// provided by ThreadFactory
public Thread newThread(Runnable command)
{
return new Thread(command);
}
}
Now, we can create objects of the CustomThreadFactory class and use its newThread(Runnable command) method to create new threads on demand. In the above implementation, the newThread method just creates a new thread by calling the Thread constructor which takes a Runnable command as the parameter.
There are many classes(such as ScheduledThreadPoolExecutor , ThreadPoolExecutor etc.) that use thread factories to create new threads when needed. Those classes have constructors that accept a ThreadFactory as argument. If any custom ThreadFactory is not given then they use the default implementation of ThreadFactory interface.
The Executors class in java.util.concurrent package provides Executors.defaultThreadFactory() static method that returns a default implementation of ThreadFactory interface.
Example: Below example code demonstrates ThreadFactory interface.
Java
// Java code to demonstrate ThreadFactory interface
import java.util.concurrent.ThreadFactory;
import java.io.*;
import java.util.ArrayList;
class ThreadFactoryExample {
public static void main(String[] args)
{
// Creating a CustomThreadFactory object
CustomThreadFactory threadFactory
= new CustomThreadFactory();
// Creating Runnable objects using the lambda
// expression
Runnable command1 = ()
-> System.out.println("Command 1 executed");
Runnable command2 = ()
-> System.out.println("Command 2 executed");
Runnable command3 = ()
-> System.out.println("Command 3 executed");
Runnable command4 = ()
-> System.out.println("Command 4 executed");
Runnable command5 = ()
-> System.out.println("Command 5 executed");
// Putting the commands in an ArrayList
ArrayList<Runnable> array = new ArrayList<>(5);
array.add(command1);
array.add(command2);
array.add(command3);
array.add(command4);
array.add(command5);
// creating threads and running them
for (Runnable command : array) {
threadFactory.newThread(command).start();
}
// print the thread count
System.out.println(
"Total number of threads created using CustomThreadFactory = "
+ threadFactory.getCount());
}
}
// ThreadFactory class
class CustomThreadFactory implements ThreadFactory {
// stores the thread count
private int count = 0;
// returns the thread count
public int getCount() { return count; }
// Factory method
@Override
public Thread newThread(Runnable command)
{
count++;
return new Thread(command);
}
}
OutputCommand 1 executed
Command 2 executed
Command 4 executed
Command 3 executed
Command 5 executed
Total number of threads created using CustomThreadFactory = 5
Why use ThreadFactory?
In the above example, the newThread(Runnable) factory method ultimately creates a new thread using the given Runnable command. Then why use ThreadFactory? We could directly create threads from the Runnable commands by calling the Thread constructor that we did in the newThread(Runnable) method. Here are some reasons,
- We can give the threads more meaningful custom names. It helps in analyzing their purposes and how they work.
- We can have the statistics about the created threads like the count of threads and other details. We can restrict the creation of new threads based on the statistics.
- We can set the daemon status of threads.
- We can set the thread priority.
- We can have all the features confined in one class.
Default Thread Factory
It is the default thread factory that is implemented by the Executors.defaultThreadFactory() static method. This default ThreadFactory is used by many classes (such as ScheduledThreadPoolExecutor, ThreadPoolExecutor etc.) when they are not given any custom ThreadFactory. Those classes create new threads using the default ThreadFactory. This default ThreadFactory creates all the new threads in the same ThreadGroup(A ThreadGroup represents a group of threads). All the created new threads are non-daemon with priority set to the smallest of Thread.NORM_PRIORITY and the maximum priority permitted in the ThreadGroup. The threads created by this default ThreadFactory are given names in the form of pool-N-thread-M (As examples, pool-1-thread-1, pool-1-thread-2, pool-2-thread-1 etc.) where N is the sequence number of this factory, and M is the sequence number of the threads created by this factory.
Example: The below example demonstrates how the default ThreadFactory can be used.
Java
// Java program to demonstrate default
// ThreadFactory
import java.io.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
class DefaultThreadFactoryExample {
public static void main(String[] args)
{
// Default ThreadFactory
ThreadFactory threadFactory
= Executors.defaultThreadFactory();
for (int i = 1; i < 10; i++) {
// Creating new threads with the default
// ThreadFactory
Thread thread
= threadFactory.newThread(new Command());
// print the thread names
System.out.println(
"Name given by threadFactory = "
+ thread.getName());
// run the thread
thread.start();
}
}
}
class Command implements Runnable {
@Override public void run()
{
// Run some code
}
}
OutputName given by threadFactory = pool-1-thread-1
Name given by threadFactory = pool-1-thread-2
Name given by threadFactory = pool-1-thread-3
Name given by threadFactory = pool-1-thread-4
Name given by threadFactory = pool-1-thread-5
Name given by threadFactory = pool-1-thread-6
Name given by threadFactory = pool-1-thread-7
Name given by threadFactory = pool-1-thread-8
Name given by threadFactory = pool-1-thread-9
Note the names of threads given by default ThreadFactory. It has created 9 threads and all the threads are in the same ThreadGroup. All the threads are created using the same ThreadFactory(so the names of the threads are in form of pool -1 -thread-M).
Example:
Java
// Java program to demonstrate ThreadFactory
// using default implementation
import java.io.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
class DefaultThreadFactoryExample {
public static void main(String[] args)
{
for (int i = 1; i < 10; i++) {
// Default ThreadFactory
ThreadFactory threadFactory
= Executors.defaultThreadFactory();
// Creating new threads with the default
// ThreadFactory
Thread thread
= threadFactory.newThread(new Command());
// print the thread name
System.out.println(
"Name given by threadFactory = "
+ thread.getName());
// start the thread
thread.start();
}
}
}
class Command implements Runnable {
@Override public void run()
{
// Run some code
}
}
OutputName given by threadFactory = pool-1-thread-1
Name given by threadFactory = pool-2-thread-1
Name given by threadFactory = pool-3-thread-1
Name given by threadFactory = pool-4-thread-1
Name given by threadFactory = pool-5-thread-1
Name given by threadFactory = pool-6-thread-1
Name given by threadFactory = pool-7-thread-1
Name given by threadFactory = pool-8-thread-1
Name given by threadFactory = pool-9-thread-1
Here, We have used 9 different default ThreadFactories(in each loop we are creating a new one!). So each thread is in different ThreadGroup and thus the threads are given name in form of pool-N-thread-1.
The default ThreadFactory implementation creates non-daemon threads with normal priority and gives names in form of pool-N-thread-M which contains no information about how they work and what they do. This creates lots of problems in debugging and other important purposes. However, this problem can be solved using a custom ThreadFactory which can give more meaningful names to the threads and can set the daemon and priority statuses.
Methods of ThreadFactory
METHOD
| DESCRIPTION
|
---|
newThread(Runnable r) | Constructs a new Thread. |
Similar Reads
Java Tutorial Java is a high-level, object-oriented programming language used to build web apps, mobile applications, and enterprise software systems. Known for its Write Once, Run Anywhere capability, which means code written in Java can run on any device that supports the Java Virtual Machine (JVM).Syntax and s
10 min read
Basics
Introduction to JavaJava is a high-level, object-oriented programming language developed by Sun Microsystems in 1995. It is platform-independent, which means we can write code once and run it anywhere using the Java Virtual Machine (JVM). Java is mostly used for building desktop applications, web applications, Android
4 min read
Java Programming BasicsJava is one of the most popular and widely used programming language and platform. A platform is an environment that helps to develop and run programs written in any programming language. Java is fast, reliable and secure. From desktop to web applications, scientific supercomputers to gaming console
4 min read
Java MethodsJava Methods are blocks of code that perform a specific task. A method allows us to reuse code, improving both efficiency and organization. All methods in Java must belong to a class. Methods are similar to functions and expose the behavior of objects.Example: Java program to demonstrate how to crea
7 min read
Access Modifiers in JavaIn Java, access modifiers are essential tools that define how the members of a class, like variables, methods, and even the class itself, can be accessed from other parts of our program. They are an important part of building secure and modular code when designing large applications. In this article
6 min read
Arrays in JavaIn Java, an array is an important linear data structure that allows us to store multiple values of the same type. Arrays in Java are objects, like all other objects in Java, arrays implicitly inherit from the java.lang.Object class. This allows you to invoke methods defined in Object (such as toStri
9 min read
Java StringsIn Java, a String is the type of object that can store a sequence of characters enclosed by double quotes and every character is stored in 16 bits, i.e., using UTF 16-bit encoding. A string acts the same as an array of characters. Java provides a robust and flexible API for handling strings, allowin
8 min read
Regular Expressions in JavaIn Java, Regular Expressions or Regex (in short) in Java is an API for defining String patterns that can be used for searching, manipulating, and editing a string in Java. Email validation and passwords are a few areas of strings where Regex is widely used to define the constraints. Regular Expressi
7 min read
OOPs & Interfaces
Classes and Objects in JavaIn Java, classes and objects are basic concepts of Object Oriented Programming (OOPs) that are used to represent real-world concepts and entities. A class is a template to create objects having similar properties and behavior, or in other words, we can say that a class is a blueprint for objects.An
10 min read
Java ConstructorsIn Java, constructors play an important role in object creation. A constructor is a special block of code that is called when an object is created. Its main job is to initialize the object, to set up its internal state, or to assign default values to its attributes. This process happens automaticall
10 min read
Java OOP(Object Oriented Programming) ConceptsBefore Object-Oriented Programming (OOPs), most programs used a procedural approach, where the focus was on writing step-by-step functions. This made it harder to manage and reuse code in large applications.To overcome these limitations, Object-Oriented Programming was introduced. Java is built arou
10 min read
Java PackagesPackages in Java are a mechanism that encapsulates a group of classes, sub-packages and interfaces. Packages are used for: Prevent naming conflicts by allowing classes with the same name to exist in different packages, like college.staff.cse.Employee and college.staff.ee.Employee.They make it easier
8 min read
Java InterfaceAn Interface in Java programming language is defined as an abstract type used to specify the behaviour of a class. An interface in Java is a blueprint of a behaviour. A Java interface contains static constants and abstract methods. Key Properties of Interface:The interface in Java is a mechanism to
11 min read
Collections
Exception Handling
Java Exception HandlingException handling in Java is an effective mechanism for managing runtime errors to ensure the application's regular flow is maintained. Some Common examples of exceptions include ClassNotFoundException, IOException, SQLException, RemoteException, etc. By handling these exceptions, Java enables deve
8 min read
Java Try Catch BlockA try-catch block in Java is a mechanism to handle exceptions. This make sure that the application continues to run even if an error occurs. The code inside the try block is executed, and if any exception occurs, it is then caught by the catch block.Example: Here, we are going to handle the Arithmet
4 min read
Java final, finally and finalizeIn Java, the keywords "final", "finally" and "finalize" have distinct roles. final enforces immutability and prevents changes to variables, methods, or classes. finally ensures a block of code runs after a try-catch, regardless of exceptions. finalize is a method used for cleanup before an object is
4 min read
Chained Exceptions in JavaChained Exceptions in Java allow associating one exception with another, i.e. one exception describes the cause of another exception. For example, consider a situation in which a method throws an ArithmeticException because of an attempt to divide by zero.But the root cause of the error was an I/O f
3 min read
Null Pointer Exception in JavaA NullPointerException in Java is a RuntimeException. It occurs when a program attempts to use an object reference that has the null value. In Java, "null" is a special value that can be assigned to object references to indicate the absence of a value.Reasons for Null Pointer ExceptionA NullPointerE
5 min read
Exception Handling with Method Overriding in JavaException handling with method overriding in Java refers to the rules and behavior that apply when a subclass overrides a method from its superclass and both methods involve exceptions. It ensures that the overridden method in the subclass does not declare broader or new checked exceptions than thos
4 min read
Java Advanced
Java Multithreading TutorialThreads are the backbone of multithreading. We are living in the real world which in itself is caught on the web surrounded by lots of applications. With the advancement in technologies, we cannot achieve the speed required to run them simultaneously unless we introduce the concept of multi-tasking
15+ min read
Synchronization in JavaIn multithreading, synchronization is important to make sure multiple threads safely work on shared resources. Without synchronization, data can become inconsistent or corrupted if multiple threads access and modify shared variables at the same time. In Java, it is a mechanism that ensures that only
10 min read
File Handling in JavaIn Java, with the help of File Class, we can work with files. This File Class is inside the java.io package. The File class can be used to create an object of the class and then specifying the name of the file.Why File Handling is Required?File Handling is an integral part of any programming languag
6 min read
Java Method ReferencesIn Java, a method is a collection of statements that perform some specific task and return the result to the caller. A method reference is the shorthand syntax for a lambda expression that contains just one method call. In general, one does not have to pass arguments to method references.Why Use Met
9 min read
Java 8 Stream TutorialJava 8 introduces Stream, which is a new abstract layer, and some new additional packages in Java 8 called java.util.stream. A Stream is a sequence of components that can be processed sequentially. These packages include classes, interfaces, and enum to allow functional-style operations on the eleme
15+ min read
Java NetworkingWhen computing devices such as laptops, desktops, servers, smartphones, and tablets and an eternally-expanding arrangement of IoT gadgets such as cameras, door locks, doorbells, refrigerators, audio/visual systems, thermostats, and various sensors are sharing information and data with each other is
15+ min read
JDBC TutorialJDBC stands for Java Database Connectivity. JDBC is a Java API or tool used in Java applications to interact with the database. It is a specification from Sun Microsystems that provides APIs for Java applications to communicate with different databases. Interfaces and Classes for JDBC API comes unde
12 min read
Java Memory ManagementJava memory management is the process by which the Java Virtual Machine (JVM) automatically handles the allocation and deallocation of memory. It uses a garbage collector to reclaim memory by removing unused objects, eliminating the need for manual memory managementJVM Memory StructureJVM defines va
4 min read
Garbage Collection in JavaGarbage collection in Java is an automatic memory management process that helps Java programs run efficiently. Java programs compile to bytecode that can be run on a Java Virtual Machine (JVM). When Java programs run on the JVM, objects in the heap are created, which is a portion of memory dedicated
7 min read
Memory Leaks in JavaIn programming, a memory leak happens when a program keeps using memory but does not give it back when it's done. It simply means the program slowly uses more and more memory, which can make things slow and even stop working. Working of Memory Management in JavaJava has automatic garbage collection,
3 min read
Practice Java
Java Interview Questions and AnswersJava is one of the most popular programming languages in the world, known for its versatility, portability, and wide range of applications. Java is the most used language in top companies such as Uber, Airbnb, Google, Netflix, Instagram, Spotify, Amazon, and many more because of its features and per
15+ min read
Java Programs - Java Programming ExamplesIn this article, we will learn and prepare for Interviews using Java Programming Examples. From basic Java programs like the Fibonacci series, Prime numbers, Factorial numbers, and Palindrome numbers to advanced Java programs.Java is one of the most popular programming languages today because of its
8 min read
Java Exercises - Basic to Advanced Java Practice Programs with SolutionsLooking for Java exercises to test your Java skills, then explore our topic-wise Java practice exercises? Here you will get 25 plus practice problems that help to upscale your Java skills. As we know Java is one of the most popular languages because of its robust and secure nature. But, programmers
7 min read
Java Quiz | Level Up Your Java SkillsThe best way to scale up your coding skills is by practicing the exercise. And if you are a Java programmer looking to test your Java skills and knowledge? Then, this Java quiz is designed to challenge your understanding of Java programming concepts and assess your excellence in the language. In thi
1 min read
Top 50 Java Project Ideas For Beginners and Advanced [Update 2025]Java is one of the most popular and versatile programming languages, known for its reliability, security, and platform independence. Developed by James Gosling in 1982, Java is widely used across industries like big data, mobile development, finance, and e-commerce.Building Java projects is an excel
15+ min read