Can we start a thread twice?

No, A thread can never be started again after starting once. It will throw IllegalThreadStateException. Example: ThreadExample.java /** * This program is used to show that we can not start * a thread which is already started. * @author w3schools */ class Test extends Thread{ public void run(){ System.out.println("thread started."); } }   public class … Read more

Daemon thread in java

Daemon thread: Daemon threads are low priority threads which are act as a service provider for user threads. Life of a daemon thread is depends upon the user threads. JVM automatically terminates daemon thread when all user threads are died. Daemon threads are used for background supporting tasks. Methods used for daemon threads: 1. public … Read more

Joining a thread in java

public final void join() The current thread invokes this method on a second thread, causing the current thread to block until the second thread terminates. We have to use join method when a thread wants to wait until some other thread will complete. Current thread will go in waiting state and it will be in … Read more

Naming a thread in java

1. public final void setName(String name) Changes the name of the thread. name – new name for this thread. 2. public final String getName() Returns this thread’s name. Example: ThreadExample.java /** * This program is used to show the thread naming example. * @author w3schools */ class Test extends Thread{ public void run(){ //Thread.currentThread()returns the current thread. System.out.println("Id of … Read more

Thread priority in java

Thread priority: Thread priority represents a number between 1 to 10. It helps the operating system to determine the order in which threads are scheduled. Static fields for thread priority defined in Thread class: 1. public static final int MIN_PRIORITY The minimum priority that a thread can have. Default value : 1 2. public static final int … Read more

Thread Scheduling in java

Thread Scheduling: Execution of multiple threads on a single CPU in some order is called thread scheduling. It is done by thread scheduler. Thread scheduler: In which order threads will execute in multithreading environment is determined by thread scheduler. What is the difference between preemptive scheduling and time slicing? In case of preemptive scheduling the … Read more

Methods of Thread class

1. public void start() starts thread to begin execution, JVM calls run method of this thread. IllegalThreadStateException – if the thread was already started. 2. public void run() run method is used to perform operations by thread. 3. public final void setName(String name) Changes the name of the thread. name – new name for this thread. 4. public final String getName() … Read more

Way of creating thread in java

Way of creating thread: By implementing Runnable interface. By extending Thread class. Important points: We discussed earlier that every thread has a job associated with it. This job is what we are performing in run method. By default every program have one main thread. It may have number of daemon threads. GC is a daemon … Read more

Thread life cycle in java

Thread life cycle: New. Runnable. Running. Blocked(Non-Runnable). Dead. Diagram:   1. New: A new thread is created but not working. A thread after creation and before invocation of start() method will be in new state. 2. Runnable: A thread after invocation of start() method will be in runnable state. A thread in runnable state will … Read more