• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Liutauras Vilda
  • Paul Clapham
  • Bear Bibeault
  • Jeanne Boyarsky
Sheriffs:
  • Ron McLeod
  • Tim Cooke
  • Devaka Cooray
Saloon Keepers:
  • Tim Moores
  • Tim Holloway
  • Jj Roberts
  • Stephan van Hulst
  • Carey Brown
Bartenders:
  • salvin francis
  • Scott Selikoff
  • fred rosenberger

Methods belong to Thread class???

 
Greenhorn
Posts: 23
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Somehow I saw two questions:

From a mock exam:
Which of the following methods belong to an instance of Thread?
wait() is one of the answer, the explanation is that Thread object is an Object so it has wait() method.

From a textbook:
Which of the following methods are defined in class Thread?
wait() is considered as a wrong answer.

I want to ask about the difference of the answer. Because wait() in Thread object is inherited from Object class where it is FIRST defined, so Thread object has a wait() method but doesn't define it. Am I correct? Thank You.
 
Greenhorn
Posts: 22
Java
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Yes Wai, you are right. Every object type inherits wait() method of Object class but wait() method does not belong to Thread class.
 
Ranch Hand
Posts: 54
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The idea here is that wait(), notify, and notifyall() methods belong to java.lang.Object, while other thread related methods such sleep(), yield(), join(), and setPriority(int a) belong to java.lang.Thread. So even though all objects (even Thread class objects) inherit from the Object class and can use its methods, but the methods of class Object such as wait() are part of the Object class. Further more these methods are final and so cannot be overrridden in subclasses.

Fes D Gaur
 
Ranch Hand
Posts: 378
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
i have a question. Interface Runnable has a method called run(), right?

But in my college textbook got one statement "The Thread class contains a method called run()."

i wonder is it means that Thread class actually provide the implementation of run() if we implements Runnable???

in final,

java.lang.Object has 3 methods : wait(), notify(), notifyAll().
Thread has : yield(), start(), sleep(), join(), isAlive(), setPriority().
Runnable has : run().


correct me if i'm wrong. thanks.
[ June 29, 2005: Message edited by: Nicky Eng ]
 
Ranch Hand
Posts: 47
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
hi,
The Thread class itself implements Runnable interface, and provide an implementation of run(). The run method simply execute the run method of a runnable object that is passed through it through the constructor of the Thread.
[ June 29, 2005: Message edited by: Vipin Das ]
 
Nicky Eng
Ranch Hand
Posts: 378
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
there is a question under k&b book(exam 310-035& 310-025, page 540, question 2, about class Thread.

question is:

Which two of the following methods are defined in class Thread?
A. start()
B. wait()
C. notify()
D. run()
E. terminate()
--------------------
my first answer was "answer A. start()". i know the question ask me to choose TWO. but i dont understand why run() will also be the answer.

is it because Thread implements Runnable and then run() will be defined in class Thread since class Thread implements Runnable and have to provide the implementation?

my second time answering this question on the MasterExam questions i mark run() and start().

i hope i wont get wrong on this in my saturday test coming soon.
 
Do you pee on your compost? Does this tiny ad?
Thread Boost feature
https://coderanch.com/t/674455/Thread-Boost-feature
reply
    Bookmark Topic Watch Topic
  • New Topic