Thread: B-Tree to B+ Tree

I've just started learning about BTrees and B+ Trees and I'm a little lost. I have 3 classes that implement the insert method for BTrees. BTreeNode, BTree, and BTreeTest. What I want to know is that besides changing the number of keys for the internal nodes from 2T-1 to M-1, and the children from 2T to M, number of keys for the leafs from 2T-1 to L, and the number of children from 2T to M, how else would I need to change my code in order for it to work for B+ Trees. On my BTreeNode class I have the insert method and on the BTree class I have it to where it checks if you have to split the root before inserting a new key. The duplicate method just makes sure there's no duplicates.
These are my methods:

public class BTreeNode{
	public int[] key;
	public BTreeNode[] c;
	boolean isLeaf;
	public int[] nextLeaf;
	public int n;
	private int T; //Each node has at least T-1 and at most 2T-1 keys
	public int min;
	public int max;
 
	public  BTreeNode(int t){
		T = t;
		isLeaf = true;
		key = new int[2*T-1];
		c = new BTreeNode[2*T];
		n = 0;
	}
        public void insert(int newKey){
		// Insert new key to current node
		// Make sure that the current node is not full by checking and
		// splitting if necessary before descending to node
 
		if(duplicate(newKey) == false){
			int i = n-1;
			if(isLeaf){
				while((i >= 0) && (newKey < key[i])) {
					key[i+1] = key[i];
					i--;
				}
				n++;
				key[i + 1] = newKey;
			}
			else{
				while ((i >= 0) && (newKey < key[i])) {
					i--;
				}
				int insertChild = i + 1;  // Subtree where new key must be inserted
				if(c[insertChild].isFull()){
					// The root of the subtree where new key will be inserted has to be split
					// update keys and references accordingly
 
					n++;
					c[n] = c[n-1];
					for(int j = n - 1; j > insertChild; j--){
						c[j] = c[j-1];
						key[j] = key[j-1];
					}
					key[insertChild] = c[insertChild].key[T - 1];
					c[insertChild].n = T - 1;
 
					BTreeNode newNode = new BTreeNode(T);
					for(int k = 0; k < T - 1; k++){
						newNode.c[k] = c[insertChild].c[k + T];
						newNode.key[k] = c[insertChild].key[k + T];
					}
 
					newNode.c[T - 1] = c[insertChild].c[2*T-1];
					newNode.n = T-1;
					newNode.isLeaf = c[insertChild].isLeaf;
					c[insertChild+1] = newNode;
 
					if(newKey < key[insertChild]){
						c[insertChild].insert(newKey);  
 
					}
					else{
						c[insertChild + 1].insert(newKey);   
 
					}
				}
				else
					c[insertChild].insert(newKey);
 
			}
		}
		else return;
	}
}
 
public class BTree{
	private BTreeNode root;
	private int T; //2T is the maximum number of children a node can have
	private int height;
	private int firstLeaf;
 
        public void insert(int newKey){
		if (root.isFull()){//Split root;
			split();
			height++;
		}
		root.insert(newKey);
	}
}

Any help would be appreciated. Thanks in advance.