java : 3 steps to threads

EE3206/EE5805 Java programming and Applications

notes on Liang(2009), p.958-961:

Three steps to start a thread

1. create a class that implements the Runnable interface and implements the run() method.

2. new() a thread object by passing the Runnable object to the Thread class

3. start threads by invoking the start() method

////////////////////////////////////

public class TaskThreadDemo {
    public static void main(String[] args)
    {
        // create tasks
        Runnable printA = new PrintChar('a', 100);
        Runnable printB = new PrintChar('b', 100);
        Runnable print100 = new PrintNum(100);

        // 2. create thread objects by passing
        // the Runnable object to the Thread class
        Thread thread1 = new Thread(printA);
        Thread thread2 = new Thread(printB);
        Thread thread3 = new Thread(print100);

        // 3. start threads
        thread1.start();
        thread2.start();
        thread3.start();
        
    }

//////////////////////////////////////////////////

public class PrintChar implements Runnable
{
   // 1. implements th Runnable interface and implements the run() method
    
    private char charToPrint; //the characte to print
    private int times;  // the number of times to print

    public PrintChar(char c, int t)
    {
        charToPrint = c;
        times = t;

    }
     public void run()
     {
         for (int i=0; i< times; i++)
             System.out.print(charToPrint);

     }
}

///////////////////////////////////////

public class PrintNum implements Runnable
{
     private int lastNum;

     /** a task to print 1,2,3, ...i  */
     public PrintNum(int n)
     {
         lastNum =n;

     }

     public void run()
     {
         for(int i=1; i<= lastNum; i++)
             System.out.print(" " + i);
     }
}