7:

Which of the following statements about threading are true?

A. You can only obtain a mutually exclusive lock on methods in a class that extends Thread or implements runnable.

B. You can obtain a mutually exclusive lock on any object.

C. You can't obtain a mutually exclusive lock on any object.

D. Thread scheduling algorithms are platform dependent.

Answer: BD

8:

Consider the following statement:

Thread myThread = new Thread();

Which of the following statements are true regarding myThread?

A. The thread myThread is now in a runnable state.

B. The thread myThread has a priority of 5.

C. On calling the start() method on myThread, the run method in the Thread class will be executed.

D. On calling the start() method on myThread, the run method in the calling class will be executed.

Answer: C

Note: the priority of myThread will be inherited from the Thread that called the constructor.

9:

What is the effect of issuing a wait() method on an object？（Mutiple）

1) If a notify() method has already been sent to that object then it has no effect

2) The object issuing the call to wait() will halt until another object sends a notify() or notifyAll() method

3) An exception will be raised

4) The object issuing the call to wait() will be automatically synchronized with any other objects using the receiving object.

ANSWER 1)

10:

Pick all the true statements below.

1) If a thread wants to call wait() on an object, the thread must own that object's lock.

2) There is a method that you can call on an instance of the Thread class that puts the instance to sleep for a specified　　number of milliseconds.

3) At the moment when a thread is notified, it automatically gets the lock of the object for which it was waiting.

ANSWER 1

11:

1. class Z {

2.　 public static void main(String[] args) {

3.　　 new Z();

4.　 }

5.

6.　 Z() {

7.　　 Z alias1 = this;

8.　　 Z alias2 = this;

9.　　 synchronized(alias1) {

10.　　 try {

11.　　 alias2.wait();

12.　　 System.out.println("DONE WAITING");

13.　　 }

14.　　 catch (InterruptedException e) {

15.　　 System.out.println("INTERRUPTED");

16.　　 }

17.　　 catch (Exception e) {

18.　　 System.out.println("OTHER EXCEPTION");

19.　　 }

20.　　 finally {

21.　　 System.out.println("FINALLY");

22.　　 }

23.　　 }

24.　　 System.out.println("ALL DONE");

25.　 }

26. }

Mutiple:

1) Compiler error.

2) The application compiles but doesn't print anything.

3) The application prints "DONE WAITING".

4) The application prints "INTERRUPTED".

5) The application prints "OTHER EXCEPTION".

ANS: 2)

12:

What will happen when you attempt to compile and run the following code?

class MyThread extends Thread{

public void run(){

System.out.println("MyThread: run()");

}

public void start(){////注意，此方法重寫后，不再有CALL RUN（）方法的功能。

System.out.println("MyThread: start()");

}

}

class MyRunnable implements Runnable{

public void run(){

System.out.println("MyRunnable: run()");

}

public void start(){//Runnable 并無此方法，所以，除非本類的對(duì)象可以CALL 它，否則，將CALL THREAD 的start()執(zhí)行run()

System.out.println("MyRunnable: start()");

}

}

public class MyTest {

public static void main(String args[]){

MyThread myThread　=　new MyThread();

MyRunnable myRunnable = new MyRunnable();

Thread thread　=　new Thread(myRunnable);

myThread.start();

thread.start();

}

}

A.prints: MyThread: start() followed by MyRunnable: run()

B.prints: MyThread: run() followed by MyRunnable: start()

C.prints: MyThread: start() follow

編輯推薦：

JAVA認(rèn)證公共基礎(chǔ)知識(shí)指導(dǎo)練習(xí)題匯總

JAVA認(rèn)證考試報(bào)考指南 / 更多JAVA考試模擬試題

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