CODEWITHSUNDEEP
javamultithreading
pfulop
pfulop

Reputation: 1009

Java, main code stops when the thread is started

When i start some thread in my program, everything else is stopped.

This is my Thread code...

static Thread b1 = new Thread(new Builders());
b1.run();
System.out.println("done");

This is the class Builders.

public class Builders implements Runnable {

    static boolean busy=false;
    Random r = new Random();

    public void run() {
        try{
            busy=true;
            System.out.println("ready");
            Thread.sleep(9999);
            busy=false;
            System.out.println("done");
        }
        catch(Exception e){
        }
    }
}

When I run the program , the thread is started and the program wait for the end of the thread. I thought the main point of the threads is that the code can run simultaneously. Could someone please help me understand what I'm doing wrong.

Upvotes: 3

Views: 243

Answers (3)

wattostudios
wattostudios

Reputation: 8774

You need to call the start() method. The internal code of Thread will start a new operating system thread that calls your run() method. By calling run() yourself, you're skipping the thread-allocation code, and just running it in your current Thread.

Upvotes: 1

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 727057

This is because you are not starting a thread - instead, you are executing thread's code synchronously by calling run(); you need to call start() instead.

Better yet, you should use executors.

Upvotes: 2

Tudor
Tudor

Reputation: 62469

That's because threads are started with start(), not run(), which simply calls the run method on the current thread. So it should be:

static Thread b1 = new Thread(new Builders());
b1.start();
System.out.println("done");

Upvotes: 8

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