/*
* this method always checks the status of the bridge and updates the status
* of the bridge before letting the bus in , and also gives the waiting
* numbers to the subsequent trucks if there are already 4 trucks on the
* bridge
*/
public void checkTheBridge(Truck aTruck) {
if (aTruck.getDirection().equals("left") && aTruck.getWaitingNumber() == 0)
aTruck.setWaitingNumber(updateWaitingTruck(1, 1));
else {
if (aTruck.getWaitingNumber() == 0) aTruck.setWaitingNumber(updateWaitingTruck(2, 1));
}
System.out.println(
"For waiting number " + aTruck.getWaitingNumber() + "new truck on the bridge");
synchronized (bridgeLock) {
try {
while (aTruck.getWeight() + BridgeWeight > maxBridgeWeight
|| bridgeLeftCount + bridgeRightCount >= 4
|| aTruck.getWaitingNumber() != servingTokenNumber) {
bridgeLock.notifyAll();
bridgeLock.wait();
}
BridgeWeight = BridgeWeight + aTruck.getWeight();
if (aTruck.getDirection().equals("left")) bridgeLeftCount++;
else bridgeRightCount++;
System.out.println(
"Number of Trucks on Bridge "
+ (bridgeLeftCount + bridgeRightCount)
+ " Weight of the bridge "
+ BridgeWeight);
servingTokenNumber++;
bridgeLock.notifyAll();
} catch (Exception e) {
System.out.println("Error:" + e);
}
}
}
// this method enables the truck to cross the bridge
public void crossthisTruck(Truck aTruck) {
checkTheBridge(aTruck);
// truck is on the road out side synchronized Block
try {
Thread.sleep(new Random().nextInt(200));
} catch (InterruptedException e) {
e.printStackTrace();
}
synchronized (bridgeLock) {
if (aTruck.getDirection().equals("left")) bridgeLeftCount--;
else bridgeRightCount--;
BridgeWeight -= aTruck.getWeight();
}
System.out.println(aTruck.getWaitingNumber() + "leaving Bridge");
}
