Thread: Java help, passing/filtering a array

Hello,
I wont post the whole program because it is a lot of classes, interfaces and abstract classes.


I am trying to filter a array by simply getting a value which is Z. The String representation of the whole application is

1,1,1:3,4,2:RoomA
x,y,z h,w,l name

The z parameter is suppose to filter through and only allow any Array above z > 1. It then returns the filter array.


I have done something similer but returns the full arraylist by coverting a array.

 
public static ArrayList<Room> rooms = new ArrayList<Room>();
 
public class Storey implements Buildable{
 
public static  Room[] getAllRooms()
	{
 
 
		 Room[] array = new Room[rooms.size()];
		array = rooms.toArray(array);
 
 
		return  array = rooms.toArray(array);
}		
	}

The below code needs to filter it by making anything above Z then returning it.

 
public class engine implements model {
 
public Room[] getStoreyRooms(int storey) {
 
		//storey = RoomReference.getZ();
 
 
 
		 Room[] array = new Room[Storey.rooms.size()];
 
		// array = Storey.rooms.toArray(array);
 
 
		 array.equals(storey!=1);
 
		 {
 
			// if storey.getLocation()
 
          return Storey.rooms.toArray(array);
		 }
 
 
	}

This is the class it gets it from.

public class RoomReference {
private int x;
private int y;
private int z;
private AbstractRoom abstractRoom ;
 
 
 
	public RoomReference(int x, int y, int z) {
 
 
	this.abstractRoom = abstractRoom;
 
	this.x = x;
	this.y = y;
	this.z = z;
}
	public int getX()
	{
		return x;
	}
	public int getY()
	{
		return y;
	}
	public int getZ()
	{
		return z;
	}
 
	public String toString()
	{
 
		String s = "";
 
		s += x;
		s += ",";
		s += y;
		s += ",";
		s += z;
		s += ":";
		return s;
 
	}
 
 
 
}

I hope this is enough , but if you need me to post more please dont hesitate to ask.

I want to get any array to match with the data z > 1, So it will return from the method.

Lets just say we have data populated in the arraylist.
1,1,1:3,4,2:RoomA
1,2,1:5,4,3:RoomB
1,1,2:2,2,2:RoomC

Ok , we have x,y,z ,height,width,length , name


Checking rooms with getStoreyRooms()
1,1,2:2,2,2:RoomC

As you see only one Room in the arraylist shows because the z value is higher then 1.


It needs to be implement in this method with the following parameters.
and yes it needs to be coverted to array from a arraylist as the last example.

It is in the model interface,which the content of the method must be on the engine, as shown below.

public class engine implements model {
 
public Room[] getStoreyRooms(int storey) {
 
}

Think of x,y,z as coordiates , if it is 2,2,2
[][][]
[][X][]
[][][]

z as mutiple level building
I simply want to keep the matches, and get rid of the rest. anything that matches higher then z>1

does this answer your question?,if more detail is require please reply

Lets just say we have data populated in the arraylist.
1,1,1:3,4,2:RoomA
1,2,1:5,4,3:RoomB
1,1,2:2,2,2:RoomC

Does your ArrayList in this example contain three elements? What data type are the elements?
Are they Strings? Like this: "1,1,2:2,2,2:RoomC"
Or is 1,1,2:2,2,2:RoomC a representation of the contents of a Room object?

For the example you posted, would getStoryRooms() return an array with a single element?
A Room with the value: 1,1,2:2,2,2:RoomC

yes, i have a room class and yes it is a representation of Room ,


This is the AbstractRoom class it implements Room.

Under AbstractRoom are the classes that contain the values of each element used for the arraylist, such as the class RoomReference with x,y,z. class Rectangle with width height length, and this name on this class private String name is the roomsname. It connects with different classes then combines together, the linking of each class is correct since the other method getAllRooms() is successful, now i am trying to filter using the (z>1). I can attach the uml diagram if needed?

igorne the other arraylists.

public interface Room extends Buildable{
 
	public void addExit();
	public void addItem();
	public String getExit();
	public ExitPoint getExitList();
	public String getItem();
	public String getItemList();
	public RoomReference getLocation();
    public String getName();
	public void removeExit();
	public void removeItem();
	public String toString();
	public Object getExit(String string);
 
 
 
 
 
}

public abstract class AbstractRoom implements Room{
 
 
	private  String name;
	private RoomReference location;
	private ArrayList<ExitPoint> exits = new ArrayList<ExitPoint>();
	private ArrayList<Item> items = new ArrayList<Item>();
 
	public AbstractRoom(RoomReference location, String name)
	{
 
		this.location = location;
		this.name = name;
		this.items = new ArrayList<Item>();
 
	}
 
	public void addExit(ExitPoint v)
	{
		exits.add(v);
 
	}
 
	public void addItem(Item v)
	{
		items.add(v);
 
	}
	public void clearArea()
	{
		exits.clear();
		items.clear();
	}
	public ExitPoint getExit(ExitPoint v)
	{
		return v;
 
	}
	public ExitPoint getExitList()
	{
		//array list
		return null;
 
	}
	public Item getItem(Item i)
	{
		return i;
 
	}
	public String getItemList()
	{
		return null;
 
	}
	public RoomReference getLocation()
	{
 
 
		return location;
 
	}
	public String getName()
	{
		return name;
	}
	public void removeExit()
	{
 
	}
	public void removeItem()
	{
 
 
	}
 
 
}

Where is the definition of z in the definition of those two classes you just posted?
If z is not defined in the class, how can you use z's value to "filter" an instance of the class?

But once it is on its String representation, I cant slice it out to test the specify Z value

Why are you trying to work with the String representation of the class? You should be working with the Room objects.

I have created a new array on the method , as shown. String representation is needed to connect to other classes like roomReference by using the toString method.



Below is code I done. r is for RoomReference I created a instance of the object in the contractor, i can only do this without making it static.

 
	public Room[] getStoreyRooms(int storey) {
 
		storey = r.getZ();
 
 
 
 
		 Room[] a = new Room[s.rooms.size()];
 
		 System.out.println(a);	
	       if(1 > storey)
	       {
	    	   return a;
	       }				 		
		return null;
	}

This line gives me a nullpointerexception
storey = r.getZ();
I would assume it would be able to get the Z value from the RoomReference class? and not give me a null.

This line gives me a nullpointerexception
storey = r.getZ();

Does the r variable have a valid value or is its value null?
Where do you give the r variable the address of a Room object?

r is for RoomReference it reads the methond on the class that has getZ();

public engine(String name,int budget)
	{
		s = new Storey();
		o = new Owner(name, budget, budget);
		h = new House();
		RoomReference r = new RoomReference(1, 1, 1);
 
	this.name = name;
	this.budget = budget;
	}

The r variable in the engine constructor is local to the constructor. You need to move its definition outside of the constructor.

so to a different class?

I have notice it reads the local constructor but i dont know how i would implement it to read the contractor with the data it needs, i believe the method is corrected now. i need to find a way to access the data instead of the local data in the class. just give me a bit to try something out, please dont lock this thread.

        RoomReference r = null;  // define the variable here
 
 
        public engine(String name,int budget)
	{
		s = new Storey();
		o = new Owner(name, budget, budget);
		h = new House();
		r = new RoomReference(1, 1, 1);  // give it a value here
 
	this.name = name;
	this.budget = budget;
	}

I have tried the above no sucess, it still gives me a null exception.

it still gives me a null exception.

Please copy and paste the FULL text of the error message.

There are many ways for r to be null.

Are you sure that this statement:
r = new RoomReference(1, 1, 1)
is executed BEFORE you try to use the value of r?

Is there more than one r variable? And you are using one that does not have a value.

Where do you give r a value? Your code does not show where the r variable that is used in getStoreyRooms() is gettting a value.

You have the same problem in this code that you had before. You have defined a local variable with the same name as the class variable. That definition hides the class variable and does not change its value:
RoomReference r = new RoomReference(1, 1, 1);

Remove the RoomReference and leave it like this:
r = new RoomReference(1, 1, 1);

What do you expect anyone to recommend from this little post?
Is this what you are trying to do>
You have an array list containing Room objects.
You have a loop that goes through the objects in the array list and selects some based on the object's z value.
The selected objects are to be removed from the original arraylist and added to a new array list.
You then display the contents of the new arraylist.

The problem is that an incorrect object is selected and moved to the new arraylist.

The solution is to check the logic for making the selection. Why does it select an object with the incorrect z value?