This document discusses thread properties in Java, including: 1. The Thread class which provides constructors, methods, and fields to work with threads. 2. Common constructors of the Thread class like Thread(), Thread(String name), and Thread(Runnable target). 3. Methods of the Thread class like start(), run(), sleep(), getName(), and setName(). 4. Fields of the Thread class like Thread priorities MAX_PRIORITY, NORM_PRIORITY, and MIN_PRIORITY. 5. Examples of using threads for monitoring resources, listening to events, and long-running operations. The document provides an overview of the key aspects of working with threads in Java through

1. Thread Properties
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2. Objectives
On completion of this period, you would be
able to learn
• Thread class
• Constructors of Thread class
• Methods of Thread class
• Fields of Thread class
• Applications of Java threads
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3. Recap
• In the previous class we learnt
• Deadlock problem
• Threads and deadlock
• To avoid deadlock in threads
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4. Thread Class
• As we know already, Java provides two ways of
creating threads
• By extending Thread class
• By implementing the Runnable interface
• Thread class is defined in java.lang package
• The Thread class provides
• Constructors
• Methods
• Fields
• These are known as Thread properties
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5. Constructors of Thread Class
• Thread()
• Allocates a new Thread object
• Thread (String name)
• Creates a new Thread object with the given name
• Thread( Runnable target)
• Creates a Thread object for a given Runnable Object
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6. Constructors of Thread Class
Contd . . .
• Thread (Runnable target, String name)
• Creates a Thread object for a given Runnable
Object and give a name to the thread
• Thread(ThreadGroup group, String name)
• Creates a Thread object within a group and gives a
proper name for the thread
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7. Methods of Thread Class
• We have already seen several methods of Thread
class
• We will look at some more methods
• currentThread()
• Returns a reference to the currently executing thread
object
• yield()
• Causes the runtime to context switch from current
thread to next available running thread
• sleep(int n)
• Current thread sleeps for n milliseconds
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8. Methods of Thread Class
Contd . . .
• start()
• Used to start a thread
• run() method will be called
• run()
• Is the body of running thread
• To be overridden
• stop()
• Causes the thread to stop immediately
• setName (String name)
• Sets the name for the current thread
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9. Methods of Thread Class
Contd . . .
• getName()
• Returns the name of the current thread
• activeCount()
• Returns the number of active threads in the current
thread's thread group
• getThreadGroup()
• Returns the thread group to which this thread belongs
• getState()
• Returns the state of this thread
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10. Fields of Thread class
• While discussing thread priorities, we looked
at the constants of Thread
• These are the fields of Thread class, and they
are
• Thread.MAX_PRIORITY
• Thread.NORM_PRIORITY
• Thread.MIN_PRIORITY
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11. Example Program
// A simple program to demonstrate the currentThread()
method
// It also uses the setName() method Use of currentThread()
class CurrentThreadDemo {
public static void main(String args[]) {
Thread t = Thread.currentThread();
System.out.println("Current thread: " + t); of setName()
Use
// change the name of the thread
t.setName("My Thread");
System.out.println("After name change: " + t);
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12. Example Program
Contd . . .
try {
for(int n = 5; n > 0; n--) {
System.out.println(n); Delay One second
Thread.sleep(1000); To be caught when sleep()
} is called
} catch (InterruptedException e) {
System.out.println("Main thread interrupted");
Output
}
}
}
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13. Applications of Java threads
• Monitoring the state of resources
• Databases , servers etc
• Listening to events
• GUI, Networking
• Operations that take a while to complete
• Printing
• Any application that is parallel in nature
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14. Summary
• In this class, you have learnt
• Thread class
• Constructors of Thread class
• Methods of Thread class
• Fields of Thread class
• The applications of Java threads
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15. Quiz
1. start() method of Thread, in turn calls
A. execute() method
B. run() method
C. stop() method
D. None
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16. Quiz Contd..
2. Which of the following methods return a
reference to the currently executing thread
A. this()
B. super()
C. currentThread()
D. No such method
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17. Quiz Contd..
3. Which of the following method must be
overridden to create a user thread
A. start() method
B. run() method
C. stop() method
D. None
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18. Quiz Contd..
4. Which of the following methods context
switch to another thread
A. run()
B. sleep()
C. yield()
D. No such method
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19. Frequently Asked Questions
1. List the methods of Thread class
2. List the different constructors of Thread class
3. List the fields of Thread class
4. What are the applications of Java threads ?
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20. Assignment
• Create a java thread, called TimerThread
• TimerThread should
• Print time continuously, for every second, in the
following format
• hh:mm:ss, where
• hh is hours
• mm is minutes
• ss is seconds
• Write a Java application to test the TimerThread
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