Answer:
Check the explanation
Explanation:
Main1.java
import java.lang.InterruptedException;
import java.lang.Thread;
import java.util.Random;
public class Main {
final private static int FARMERS = 10;
public static void main(String[] args) {
Bridge bridge = new Bridge();
Random r = new Random();
System.out.println("Running with " + FARMERS + " farmers...");
// Enter a bunch of farmers from different directions.
for (int i = 0; i < FARMERS; i++) {
Farmer farmer;
if (r.nextBoolean()) {
farmer = new SouthBoundFarmer(bridge);
} else {
farmer = new NorthBoundFarmer(bridge);
}
cross(farmer);
}
}
private static void cross(Farmer f) {
new Thread(f).start();
}
}
SouthBoundFarmer.java
public class SouthBoundFarmer extends Farmer {
public SouthBoundFarmer(Bridge b) {
super(b);
this.name = "South";
}
}
Farmer.java
import java.lang.InterruptedException;
import java.util.Random;
public class Farmer implements Runnable {
private Bridge bridge;
private Random random;
protected String name;
public Farmer(Bridge b) {
this.bridge = b;
this.random = new Random();
}
public void crossBridge(Bridge bridge) {
System.out.println("[" + this.name + "] Waiting to enter bridge...");
try {
bridge.enter();
System.out.println("[" + this.name + "] Entering bridge...");
// Crossing bridge...some farmers are fast, others are slow :P
Thread.sleep(1000 + random.nextInt(9000));
System.out.println("[" + this.name + "] Leaving bridge...");
} catch (InterruptedException e) {
System.out.println("...Interrupted!");
} finally {
bridge.leave();
}
}
public void run() {
this.crossBridge(this.bridge);
}
}
Bridge.java
import java.lang.InterruptedException;
import java.util.concurrent.Semaphore;
public class Bridge {
private Semaphore lock;
public Bridge() {
this.lock = new Semaphore(1);
}
public void enter() throws InterruptedException {
this.lock.acquire();
}
public void leave() {
this.lock.release();
}
}
NorthBoundFarmer.java
public class NorthBoundFarmer extends Farmer {
public NorthBoundFarmer(Bridge b) {
super(b);
this.name = "North";
}
}
KINDLY CHECK THE OUTPUT BELOW :
