A preliminary study of Java multithreading

Import java.io.*;


//Multithreaded programming


public class multithread


{


public static void Main (String args[])


{


System.out.println ("I am the main thread!");


//Below Create thread instance Thread1


threaduseextends thread1=new threaduseextends ();


//When creating thread2 to implement the Runnable interface Thhreaduserunnable class instance as parameter


thread thread2=new Thread (new threaduserunnable (), "Secondthread");


Thread1.start ()//start thread thread1 put it in a ready state


//thread1.setpriority (6);//Set THREAD1 priority to 6


//Priority will determine when the CPU is empty, the ready-state thread who first occupies the CPU starts to run


//Priority range 1 to 10,min_priority,max_priority,norm_paiority


//New thread inheritance creates her parent thread priority, and the parent thread usually has a normal priority, that is, 5norm_priority


System.out.println ("Main thread will hang for 7 seconds!");


Try


{


Thread.Sleep (7000);/main thread hangs 7 seconds


}


catch (interruptedexception e)


{


Return


}


System.out.println ("Back to the main thread!");


if (thread1.isalive ())


{


thread1.stop ()//If Thread1 still exists, kill him


System.out.println ("Thread1 sleep too long, the main thread killed the thread1!");


}


Else


System.out.println ("Main thread did not find Thread1,thread1 awake sequence execution ended!");


Thread2.start ()//Start thread2


System.out.println ("Main thread will hang up again for 7 seconds!");


Try


{


Thread.Sleep (7000);/main thread hangs 7 seconds


}


catch (interruptedexception e)


{


return;


}


System.out.println ("Back to the main thread!");


if (thread2.isalive ())


{


thread2.stop ()//If thread2 still exists, kill him


System.out.println ("Thread2 sleep too long, the main thread killed the thread2!");


}


Else


System.out.println ("Main thread did not find thread2,thread2 awake sequence execution ended!");


System.out.println ("Press any key at end of program to continue!");


Try


{


System.in.read ();


}


catch (IOException e)


{


System.out.println (e.tostring ());


}


}//main


}//multithread


class Threaduseextends extends Thread


//By inheriting the thread class and implementing its abstract method run ()


//When appropriate, create an instance of this thread subclass to implement multithreaded mechanisms


//A thread starts (or is in a ready state) once it gets the CPU will automatically call its run () method


{


threaduseextends () {}//constructor


public void Run ()


{


System.out.println ("I am the thread instance of the thread subclass!");


System.out.println ("I will hang up for 10 seconds!");


System.out.println ("Back to the main thread, please wait a moment, just hang up the main thread may not wake up!") ");


Try


{


sleep (10000);//Hang up 5 seconds


}


catch (interruptedexception e)


{


return;


}


If the run () method is finished sequentially, the thread will automatically end without being killed by the main thread


//But if the sleep time is too long, the thread survives and may be killed by Stop ()


}


}


class Threaduserunnable implements Runnable


///By implementing the Run () method in the Runnable interface, and then using this to implement the class of the Run () method


//Create thread instances for parameters


{


//thread thread2=new Thread (this);


//Creates a thread instance of the threads class for the parameter with this class that implements the run () method in the Runnable interface


threaduserunnable () {}//constructor


public void Run ()


{


System.out.println ("I am the thread instance of the thread class and take arguments for the class that implements the Runnable interface!");


System.out.println ("I will hang up for 1 seconds!");


System.out.println ("Back to the main thread, please wait a moment, just hang up the main thread may not wake up!") ");


Try


{


Thread.Sleep (1000);//Hang up for 5 seconds


}


catch (interruptedexception e)


{


return;


}


//If the run () method is finished sequentially, the thread will automatically end without being killed by the main thread


//But if the sleep time is too long, the thread survives and may be killed by Stop ()


}


}


//The program can make modifications such as changing the sleep time or Priority setpriority ()