public class StaticSync extends Object {
private static int nextSerialNum = 10001;
public static synchronized int getNextSerialNum() {
int sn = nextSerialNum;
try { Thread.sleep(1000); }
catch ( InterruptedException x ) { }
nextSerialNum++;
return sn;
}
private static void print(String msg) {
String threadName = Thread.currentThread().getName();
System.out.println(threadName + ": " + msg);
}
public static void main(String[] args) {
try {
Runnable r = new Runnable() {
public void run() {
print("getNextSerialNum()=" +
getNextSerialNum());
}
};
Thread threadA = new Thread(r, "threadA");
threadA.start();
Thread.sleep(1500);
Thread threadB = new Thread(r, "threadB");
threadB.start();
Thread.sleep(500);
Thread threadC = new Thread(r, "threadC");
threadC.start();
Thread.sleep(2500);
Thread threadD = new Thread(r, "threadD");
threadD.start();
} catch ( InterruptedException x ) {
// ignore
}
}
}