// Linked list hints for CDLinks, assignment #7.

// Creates a list of Nodes, implemented as a linked list. Node could be called CD.

The main program can be identical to CDstore2.java, as follows. What is different is the code that enables us to make a linked list of the CD's, instead of an array:

class CDLinks

{

public static void main (String [] args)

{

CDlist cdlist = new CDlist ();

cdlist.readData ();

cdlist.addCD ();

cdlist.displayData ();

cdlist.storeData ();

} // method main

} // class CDLinks

This might be some class CD, or, as you may call it, class Node (the name doesn't matter. It is the thing, with data fields and a next field of its own type, which will get linked into the linked list in class CDlist below):

class Node

{

private String name, artist, company, catalog;

private int orderNo = 1;

private Node next;

Constructor will include:

Node (String n, String a, String comp, String cat,

int orderNo)

assign all the data fields.

also set next equal to null.

Other methods for Node (or CD if you call it that):

public Node getNext()

public void setNext(Node next)

public void readCDData (BufferedReader infile, String n)

throws IOException

identical to array version

public void displayCD ()

identical to array version

public void storeCD (PrintStream outfile)

identical to array version

} // end class Node

// CDList, where a lot more of the pointer stuff is needed. Some clues:

// It's like the array version is some ways, with creating of newNode where

// appropriate...

class CDlist

{

private Node listHead = null;

These methods will be needed:

// Here is the code for a generic addNode, as in the linked list program online and in class:

public void addNode ( Node newNode )

{

if (listHead == null)

{

listHead = newNode;

newNode.setNext(null);

}

else // list not empty

{

Node tempPtr = listHead;

while ( tempPtr.getNext() != null )

tempPtr = tempPtr.getNext();

tempPtr.setNext( newNode );

}

} // addNode

// Please trace displayData and addNode on paper to understand it.

// This will enable you to understand how one moves around in a linked list.

public void displayData()

{

Node tempPtr = listHead;

while (tempPtr != null)

{

tempPtr.displayCD();

tempPtr = tempPtr.getNext();

}

System.out.println ();

} // displayData

// Here are a few more things:

BufferedReader stdin = new BufferedReader (new InputStreamReader

(System.in));

public void readData ()

You'll need this in the method:

// Get a Node object for the CD

Node newCDnode = new Node();

// Read the data into the object

newCDnode.readCDData (infile, name);

// Call the method in Node to add it to the linked list

addNode (newCDnode); replaces list[i].addNode();

public void addCD ()

You'll need this in this method:

// Get a Node object, using the constructor that assigns the data from the parameters:

Node newCDnode = new Node (name, artist, company, catalog, orderNo);

// Add the object to the linked list:

addNode (newCDnode);

public void storeData ()

} // class CDlist