Course
Naming a Thread with Examples
Java Tutorial
This Java tutorial is tailored for newcomers, offering a journey from basic principles to complex Java programming techniques. Completing this tutorial equips you with a solid understanding of Java, preparing you for advanced learning. You'll emerge ready to tackle the challenges of becoming a top-tier software engineer, with the skills to innovate and excel in the vast world of software development.
Naming a Thread with Examples
Name a Thread while Implementing a Runnable Interface
If your class is intended to be executed as a thread and is implementing a Runnable interface. You will need to instantiate a Thread object using the following constructor
Thread(Runnable threadObj, String threadName);Where, threadObj is an instance of a class that implements the Runnable interface and threadName is the name given to the new thread.
Once a Thread object is created, you can start it by calling start() method, which executes a call to run( ) method. Following is a simple syntax of start() method
void start();Example
In this example, we're creating a class RunnableDemo by implementing Runnable interface. RunnableDemo class has run() method implementation. In main class TestThread, we've created the RunnableDemo objects and using those objects we've created two Thread objects. When Thread.start() method is called on each thread objects, threads start processing and program is executed.
package com.tutorialspoint;class RunnableDemo implements Runnable { private String threadName; RunnableDemo( String name) { threadName = name; System.out.println("Thread: " + threadName + ", " + "State: New"); } public void run() { System.out.println("Thread: " + threadName + ", " + "State: Running"); for(int i = 4; i > 0; i--) { System.out.println("Thread: " + threadName + ", " + i); } System.out.println("Thread: " + threadName + ", " + "State: Dead"); }}public class TestThread { public static void main(String args[]) { RunnableDemo runnableDemo1 = new RunnableDemo( "Thread-1"); RunnableDemo runnableDemo2 = new RunnableDemo( "Thread-2"); Thread thread1 = new Thread(runnableDemo1); Thread thread2 = new Thread(runnableDemo2); thread1.start(); thread2.start(); }}Output
Thread: Thread-1, State: NewThread: Thread-2, State: NewThread: Thread-1, State: RunningThread: Thread-1, 4Thread: Thread-1, 3Thread: Thread-1, 2Thread: Thread-1, 1Thread: Thread-1, State: DeadThread: Thread-2, State: RunningThread: Thread-2, 4Thread: Thread-2, 3Thread: Thread-2, 2Thread: Thread-2, 1Thread: Thread-2, State: DeadNaming a Thread while extending a Thread Class
The second way to create a thread is to create a new class that extends Thread class. This approach provides more flexibility in handling multiple threads created using available methods in Thread class. In order to name the thread, we need to call the super class Thread constructor with name.
class ThreadDemo extends Thread { ThreadDemo( String name) { super(name); ... }...}Example 1
Here is the preceding program rewritten to extend the Thread − In this example, we've created a ThreadDemo class which extends Thread class. We're calling super(name) in constructor() method to assign a name to the thread and called super.start() to start the thread processing.
package com.tutorialspoint;class ThreadDemo extends Thread { ThreadDemo( String name) { super(name); System.out.println("Thread: " + name + ", " + "State: New"); } public void run() { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: Running"); for(int i = 4; i > 0; i--) { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + i); } System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: Dead"); }
public void start () { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: Start"); super.start(); }}public class TestThread { public static void main(String args[]) { ThreadDemo thread1 = new ThreadDemo( "Thread-1"); ThreadDemo thread2 = new ThreadDemo( "Thread-2"); thread1.start(); thread2.start(); }}Output
Thread: Thread-1, State: NewThread: Thread-2, State: NewThread: main, State: StartThread: main, State: StartThread: Thread-1, State: RunningThread: Thread-1, 4Thread: Thread-1, 3Thread: Thread-1, 2Thread: Thread-2, State: RunningThread: Thread-1, 1Thread: Thread-1, State: DeadThread: Thread-2, 4Thread: Thread-2, 3Thread: Thread-2, 2Thread: Thread-2, 1Thread: Thread-2, State: DeadExample 2
In this example, we've created a ThreadDemo class which extends Thread class. We're not passing any name to the Thread and it will print the default names assigned to the threads by the system.
package com.tutorialspoint;class ThreadDemo extends Thread { ThreadDemo( ) { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: New"); } public void run() { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: Running"); for(int i = 4; i > 0; i--) { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + i); } System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: Dead"); } public void start () { System.out.println("Thread: " + Thread.currentThread().getName() + ", " + "State: Start"); super.start(); }}
public class TestThread { public static void main(String args[]) { ThreadDemo thread1 = new ThreadDemo(); ThreadDemo thread2 = new ThreadDemo(); thread1.start(); thread2.start(); }}Output
Thread: main, State: NewThread: main, State: NewThread: main, State: StartThread: main, State: StartThread: Thread-0, State: RunningThread: Thread-0, 4Thread: Thread-0, 3Thread: Thread-1, State: RunningThread: Thread-0, 2Thread: Thread-1, 4Thread: Thread-0, 1Thread: Thread-1, 3Thread: Thread-0, State: DeadThread: Thread-1, 2Thread: Thread-1, 1Thread: Thread-1, State: Dead