Re: Thread + stack + synchronization.

"ppp" <jimmie0@xxxxx> wrote in message
news:1164725022.003969.308220@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I have problem with Producent-Consument-Buffer.

Below is my Buffer class with wstaw (in english PUSH) and pobierz (POP)
methods, main class Glowny and Producent class. I thint that is all ok,
but when i try to compile there is exception:

Exception in thread "Thread-0" java.lang.NullPointerException
at zadanie7a.Producent.run(Producent.java:14)

I'm correcting your terminology here: The exception didn't happen when
you tried to *compile* the program, but when you tried to *run* the program.
You compile the program using javac, and you run the program using java.

[most of code snipped]
Glowny.bufor.wstaw(s); // here is this error
[...]

///////////////////
// Main class
///////////////////

package zadanie7a;

public class Glowny {
public static int rozBufora = 10;
public static Bufor bufor;
public static String s = "Element";

public static void main(String[] args){
Producent p = new Producent();
Konsument k = new Konsument();
p.start();
}
}

The problem is that bufor is set to null by default, and you never
assign any other value to it.

- Oliver


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