Edit Values of an object in ObjectArrayList JAVA

Question

I am attempting to edit values of liftobject from LiftObject.java in a array list called lift. I'm trying to use setDirection() to change this value from 0 to 22 (supposed to be -1 but i was just testing).

LiftObject.java

package system;

import java.io.Serializable;

public class LiftObject implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    int capacity;
    int direction;
    int currentFloor;
    int LiftNum;
    int id;

    public LiftObject(int capacity, int direction, int currentFloor, int LiftNum){
        this.capacity = capacity;
        this.direction = direction;
        this.currentFloor = currentFloor;
        this.LiftNum = LiftNum;
    }

    public int getCapacity(){return this.capacity;}
    public int getDirection(){return this.direction;}
    public int getCurrentFloor(){return this.currentFloor;}
    public int getLiftNum(){return this.LiftNum;}

    public int setCapacity(int capacity){return this.capacity;}
    public int setDirection(int direction){return this.direction;}
    public int setCurrentFloor(int currentFloor){return this.currentFloor;}
    public int setLiftNum(int LiftNum){return this.LiftNum;}


}

Then the main file, TestSystem.java

package system;

public class TestSystem {
    static int TopFloor = 20;
    static int Capacity = 8;
    int W_PersCount = 0;
    int A_PersCount = 0;
    int T_PersCount = 0;
    public static ObjectArrayList lift = new ObjectArrayList();
    public static ObjectArrayList wPers = new ObjectArrayList();
    public static ObjectArrayList tPers = new ObjectArrayList();
    public static ObjectArrayList aPers = new ObjectArrayList();

    public void DirectLift() {
        System.out.println("Direct Lift Start.");
        //The lift only changes direction when it hits the top or bottom
        int CF =((LiftObject) TestSystem.lift.get(0)).getCurrentFloor();
        System.out.println("Floor: ");
        System.out.println(CF);
        if( CF == 0) {
            ((LiftObject) TestSystem.lift.get(0)).setDirection(+1);
            System.out.println(((LiftObject) TestSystem.lift.get(0)).getDirection());
        }else if(CF == TopFloor){
            ((LiftObject) TestSystem.lift.get(0)).setDirection(-1);
            System.out.println(((LiftObject) TestSystem.lift.get(0)).getDirection());
        }else {
            System.out.println("Continue");
        }

    }


    public void LiftGeneration(int capacity, int direction, int currentFloor, int LiftNum) {
        LiftObject obj = new LiftObject(capacity,direction,currentFloor,LiftNum);
        obj.capacity = capacity;
        obj.direction = direction;
        obj.currentFloor = currentFloor;
        obj.LiftNum = LiftNum;


        lift.add(obj);
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getCapacity());
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getDirection());
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getCurrentFloor());
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getLiftNum());
    }

    public void System() {
        //The lift only changes direction when it hits the top or bottom
        int CF =((LiftObject) TestSystem.lift.get(0)).getCurrentFloor();
        System.out.println("Floor: ");
        System.out.println(CF);
        System.out.println("Direct Lift Start.");
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getCapacity());
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getDirection());
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getCurrentFloor());
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getLiftNum());
        ((LiftObject)TestSystem.lift.get(0)).setDirection(22);
        System.out.println(((LiftObject) TestSystem.lift.get(0)).getDirection());

    }

    public static void main(String[] args) {
        System.out.println("Start.");
        TestSystem myObj = new TestSystem(); // Create an object of MyClass
        myObj.LiftGeneration(Capacity, 0, 0, 1);
        System.out.println("Works here");
        myObj.System();

    }

The problem is that no change occurs when I try and change the direction from 0 to -1 Any help would be greatly appreciated, thank you.

Answer 1

Your problem is here:

 public int setDirection(int direction){return this.direction;}

It should be:

 public void setDirection(int direction){this.direction = direction;}

All your setters are written the same as your getters. When you write a setter you don't return a value; you set it. You'll want to adjust all your other setters to be something similar to what is here. Otherwise, you'll have issues with them too.