Java Programming

Hi I am trying the huffman tree decoding with my own created classes. Its just 5 letters for now. here is the code of the three classes:

MAIN:

import java.io.*;

public class HuffmanTree
{
	public static void main (String[] args) throws IOException
	{
		Tree tree = new Tree();

		String character = "e";
		String code = "0";
		tree.insert(character, code);
		System.out.println("Saved " + character);

		character = "a";
		code = "10";
		tree.insert(character, code);
		System.out.println("Saved " + character);
		
		character = "d";
		code = "111";
		tree.insert(character, code);
		System.out.println("Saved " + character);

		character = "b";
		code = "1100";
		tree.insert(character, code);
		System.out.println("Saved " + character);

		character = "c";
		code = "1101";
		tree.insert(character, code);
		System.out.println("Saved " + character);

		tree.inOrder(tree.root()); //PROBLEM HERE, WHICH IS RELATED TO INSERTING
		System.out.print("Decode: ");
		//code = getString();
		//tree.search(code);
	}

	public static String getString() throws IOException
      	{
      		InputStreamReader isr = new InputStreamReader(System.in);
      		BufferedReader br = new BufferedReader(isr);
      		String s = br.readLine();
      		return s;
      	}

NODE:

import java.io.*;
import java.util.*;
import java.lang.Integer;

public class Node

   {
   private int key;
   private String ch;              // data item (key)
   private Node leftChild;         // the node's left child
   private Node rightChild;        // the node's right child

   public Node(String letter)
      {
	ch = letter;
      }
   public void displayNode()
      {
      	System.out.println('{'+ch+'}');
      }
   public Node getLeftChild()
      {
      	return leftChild;
      }
   public Node getRightChild()
      {
      	return rightChild;
      }
   public String getCh()
      {
      	return ch;
      }
   public double getKey()
      {
      	return key;
      }
   public void setLeftChild(Node lC)
      {
      	leftChild = lC;
      }
   public void setRightChild(Node rC)
      {
      	rightChild = rC;
      }
   public void setCh(String ch)

      {
      	this.ch = ch;
      }

   }

TREE:

import java.io.*;    

public class Tree
{
    	public Node root; // first node of tree
	Node rootNode = new Node("root");

    	public Tree() 
        {
        	root = rootNode;
        }         

	public Node root()
	{
		return root;
	}

	public void insert(String letter, String input)
	{
		Node newNode = new Node(letter);
		Node current = root;
		Node parent;
		
		for(int i=0; i<input.length(); i++)
        	{
			parent = current;
         		char ch = input.charAt(i);
			int bit = Character.getNumericValue(ch);
			//System.out.println("i = " + i + ", bit = " + bit + ", ch = " + ch + ", Parent: " + parent);
			if(bit == 0)
			{
				current = current.getLeftChild();
				if((i == input.length()-1) && (current == null))
				{	
					parent.setLeftChild(newNode);
					newNode.setCh(letter);			
				}
				else
				{
					Node newerNode = new Node("empty");
					parent.setLeftChild(newerNode);
					current = newerNode;
				}	
			}
			else
			{
				current = current.getRightChild();
				if((i == input.length()-1) && (current == null))
				{
					//System.out.println("Module3");
					parent.setRightChild(newNode);
					newNode.setCh(letter);
				}	
				else
				{
					//System.out.println("Module4");
					Node newerNode = new Node("empty");
					parent.setRightChild(newerNode);
					current = newerNode;
				}
			}
		}
	}

	public void search(String input)
	{        
		String test = root.getRightChild().getRightChild().getCh();
		System.out.println("Character at right is '" + test + "'");            
		Node current = root;
		Node parent;
		for(int i=0; i<input.length(); i++)
        	{
         		char ch = input.charAt(i);
			int bit = Character.getNumericValue(ch);
			//System.out.println("i = " + i + ", bit = " + bit + ", ch = " + ch);
			if(bit == 0)
			{
				current = current.getLeftChild();
				System.out.println("Left current: " + current.getCh());
				if(current.getCh() != "empty")
				{
					System.out.println("moduleLEFT");
					System.out.print(current.getCh());
					current = root;
					System.out.println(current.getCh());
				}
			}
			else
			{
				System.out.println(current + current.getCh());
				current = current.getRightChild();
				System.out.println(current.getCh());
				if(current.getCh() == "d")
				{
					System.out.println("moduleRIGHT");
					System.out.print(current.getCh());
					current = root;
				}
			}
		}  
        }

	public void display()
	{
		String test = root.getRightChild().getRightChild().getCh();
		System.out.println("Character at right is '" + test + "'");
	}

	public void inOrder(Node localRoot)
      	{
      		if(localRoot != null)
        	{
         		inOrder(localRoot.getLeftChild());
         		localRoot.displayNode();
         		inOrder(localRoot.getRightChild());
         	}
      	}
}		

When i run it i get the output:

[13818160@lab219-02 trees]$ java HuffmanTree
Saved e
Saved a
Saved d
Saved b
Saved c
{e}
{root}
{empty}
{empty}
{c}
{empty}
Decode:

The problem is when inserting as you can see, after i call inOrder to display the tree inOrder (from {e} onwards) it has empty for some reason when it should really be displaying the other letters. I have tried everything but cant seem to find the problem anymore.
Could someone help???

Thanks
Phil