Java Thread Example

Question

Could anyone give an example program that explains Java Threads in a simple way  For example  say I have three threads t1  t2 and t3  I want a code that demonstrates that the threads execute simultaneously  and not sequentially

User · Answer

There is no guarantee that your threads are executing simultaneously regardless of any trivial example anyone else posts  If your OS only gives the java process one processor to work on  your java threads will still be scheduled for each time slice in a round robin fashion  Meaning  no two will ever be executing simultaneously  but the work they do will be interleaved  You can use monitoring tools like Java s Visual VM  standard in the JDK  to observe the threads executing in a Java process

User · Answer

create java application in which you define two threads namely t1 and t2    thread t1 will generate random number 0 and 1  simulate toss a coin    0 means head and one means tail  the other thread t2  will do the same  t1  and t2 will repeat this loop 100 times and finally your application should determine how many times  t1 guesses the number generated by  t2 and then display the score  for example if thread t1 guesses 20 number out of 100 then the score of  t1 is 20 100  0 2 if  t1 guesses 100 numbers then it gets score 1  and so on

User · Answer

Here is a simple example   ThreadTest java  public class ThreadTest      public static void main String    args             MyThread t1   new MyThread 0  3  300         MyThread t2   new MyThread 1  3  300         MyThread t3   new MyThread 2  3  300          t1 start          t2 start          t3 start             MyThread java  public class MyThread extends Thread      private int startIdx  nThreads  maxIdx      public MyThread int s  int n  int m             this startIdx   s        this nThreads   n        this maxIdx   m            Override    public void run              for int i   this startIdx  i  lt  this maxIdx  i    this nThreads                   System out println   ID     this getId            i                    And some output    ID 9  1  ID 10  2  ID 8  0  ID 10  5  ID 9  4  ID 10  8  ID 8  3  ID 10  11  ID 10  14  ID 10  17  ID 10  20  ID 10  23   An explanation - Each MyThread object tries to print numbers from 0 to 300  but they are only responsible for certain regions of that range   I chose to split it by indices  with each thread jumping ahead by the number of threads total   So t1 does index 0  3  6  9  etc   Now  without IO  trivial calculations like this can still look like threads are executing sequentially  which is why I just showed the first part of the output   On my computer  after this output thread with ID 10 finishes all at once  followed by 9  then 8   If you put in a wait or a yield  you can see it better   MyThread java  System out println   ID     this getId            i   Thread yield      And the output    ID 8  0  ID 9  1  ID 10  2  ID 8  3  ID 9  4  ID 8  6  ID 10  5  ID 9  7   Now you can see each thread executing  giving up control early  and the next executing

User · Answer

A simple example   public class Test extends Thread       public synchronized void run             for  int i   0  i  lt   10  i                  System out println  i    i                        public static void main String   args            Test obj   new Test             Thread t1   new Thread obj           Thread t2   new Thread obj           Thread t3   new Thread obj            t1 start            t2 start            t3 start

[java] Java Thread Example?

Examples related to java

Examples related to multithreading