Creating a Queue Machine in Java

Problem:

Machine

- weight : int - cost : int

//constructor and set/get

Assembler

- machines : Queue<Machine>

+ Assembler() + enqueueMachine(machine : Machine) : void + finishMachine() : void + getCurrentMachine() : Machine + toString() : String

Implement the previous two classes.

Class machine has two private variables with a constructor and setters and getters. The Assembler class has a Queue of machines with the following functions:

• enqueueMachine(machine : Machine): adds a machine to the queue
• finishMachine(): removes the machine at the front of the queue
• getCurrentMachine(): returns the machine at the front of the queue 

Solution:

/**---------------------------Assembler.java--------------------------*/
import java.util.LinkedList;
import java.util.Queue;

public class Assembler
{
 private Queue  machines = new LinkedList();
 
 public Assembler()
 {
  
 }
 
 public void enqueueMachine(Machine machine)
 {
  machines.offer(machine);
 }
 
 public void finishMachine()
 {
  machines.poll();
 }
 
 public Machine getCurrentMachine()
 {
  return machines.element();
 }

 public String toString() {
  return "Machines are: " + machines + "\n";
 }

}
/**---------------------------Machine.java--------------------------*/

public class Machine
{
 private int weight;
 private int cost;
 
 
 public Machine(int weight, int cost) {
  this.weight = weight;
  this.cost = cost;
 }


 public int getWeight() {
  return weight;
 }


 public void setWeight(int weight) {
  this.weight = weight;
 }


 public int getCost() {
  return cost;
 }


 public void setCost(int cost) {
  this.cost = cost;
 }


 public String toString() {
  return "Cost: " + cost + " Weight: " + weight;
 }
 
 
 
}
/**---------------------------Tester.java--------------------------*/
public class Tester
{
 public static void main(String[] args)
 {
  Assembler assembler = new Assembler();
  
  assembler.enqueueMachine(new Machine(1,10));
  assembler.enqueueMachine(new Machine(2,20));
  assembler.enqueueMachine(new Machine(3,30));
  assembler.enqueueMachine(new Machine(4,40));

  System.out.println(assembler);
  
  assembler.finishMachine();
  
  System.out.println(assembler);

  System.out.println(assembler.getCurrentMachine());
 }
}