网上有关于二叉数的java实现http://blog.csdn.net/skylinesky/article/details/6611442

多数案例都没有键值，有键值的也全是整型。我用java实现了一个可以任何对象为键的二叉数

package Tree;

import java.io.IOException;

public class Tree<I extends Comparable<I> ,V> {
	
	@SuppressWarnings("rawtypes")
	private Node root;
	
	@SuppressWarnings("unchecked")
	public Node<I, V> getRoot() {
		return root;
	}

	public void setRoot(Node<I, V> root) {
		this.root = root;
	}

	//向树添加节点
	@SuppressWarnings({ "unchecked" })
	public void add(I index,V value){
		
		if(root == null){
			root = new Node<I, V>(index,value);
			System.out.println(root);
		}else{
			Node<I, V> current = root;
			Node<I, V> parent = null;
			while(true){
				parent = current;
				int result = index.compareTo(current.getIndex());
				if(result < 0){
					current = current.getLeft();
					if(current == null){
						current = new Node<I, V>(index,value);
						parent.setLeft(current);
						return ;
					}
				}else{
					current = current.getRight();
					if(current == null){
						current = new Node<I, V>(index,value);
						parent.setRight(current);
						return ;
					}
				}
			}
		}
		
	}
	
	//查找
	@SuppressWarnings("unchecked")
	public Node<I, V> find(I index){
		Node<I, V> current = root;
		int result = index.compareTo(current.getIndex()); 
		while(result != 0){
			if(result < 0){
				current = current.getLeft();
			}else {
				current = current.getRight();
			}
			if(current == null){
				return null;
			}
			result = index.compareTo(current.getIndex()); 
		}
		
		return current;
	}
	
	//中序遍历
	public void centerTraversal(Node<I, V> node){
		if(node != null){
			centerTraversal(node.getLeft());
			System.out.println(node);
			centerTraversal(node.getRight());
		}
	}
	
	//前序遍历
	public void leftTraversal(Node<I, V> node){
		if(node != null){
			System.out.println(node);
			centerTraversal(node.getLeft());
			centerTraversal(node.getRight());
		}
	}
	
	//后序遍历
	public void rightTraversal(Node<I, V> node){
		if(node != null){
			System.out.println(node);
			centerTraversal(node.getLeft());
			centerTraversal(node.getRight());
		}
	}
	
	@SuppressWarnings("unchecked")
	public void delete(I index){
		
		Node<I, V> current = root;
		boolean isLeft = true;
		Node<I, V> parent = null;
		int result = index.compareTo(current.getIndex()); 
		
		//找到要删除的结点
		while(result != 0){
			parent = current;
			System.out.println(current.getIndex());
			if(result < 0){
				current = current.getLeft();
				isLeft = true;
			}else {
				current = current.getRight();
				isLeft = false;
			}
			if(current == null){
				throw new RuntimeException(" \"" + index + "\" 没有这个节点");
			}
			result = index.compareTo(current.getIndex()); 
		}
		
		//这个要删除的节点没有子结点
		if(current.getLeft() == null && current.getRight() == null){
			if(current == root){
				root = null;
			}else{				
				if(isLeft){
					parent.setLeft(null);
				}else{
					parent.setLeft(null);
				}
			}
		}else if(current.getRight() == null){
			//只有左子结点
			
			if(current == root){
				root = root.getLeft();
			}else{				
				if(isLeft){
					parent.setLeft(current.getLeft());
				}else{
					parent.setRight(current.getLeft());
				}
			}
		//只有右子结点
		}else if(current.getLeft() == null){
			if(current == root){
				root = root.getRight();
			}else{				
				if(isLeft){
					parent.setLeft(current.getRight());
				}else{
					parent.setRight(current.getRight());
				}
			}
		}else{
			//左右子节点都有的情况下，
			Node<I,V> follow = current;
			Node<I,V> followParent = follow;
			Node<I,V> followCurrent = follow.getRight();
			
			if(followCurrent.getLeft() == null){
				if(isLeft){
					parent.setLeft(current.getRight());
				}else{
					parent.setRight(current.getRight());
				}
				current.getRight().setLeft(current.getLeft());
			}else{
				while(followCurrent != null){
					followParent = follow;
					follow = followCurrent;
					followCurrent = followCurrent.getLeft();
				}
				followParent.setLeft(follow.getRight());
				if(isLeft){
					parent.setLeft(follow);
				}else{
					parent.setRight(follow);
				}
				follow.setLeft(current.getLeft());
				follow.setRight(current.getRight());
			}
			
			
		}
		
	}
	
	 public static void main(String[] args) throws IOException{
	     Tree<Integer,Double> tree = new Tree<Integer,Double>();
	     tree.add(50, 1.5);
	     tree.add(25, 1.2);
	     tree.add(75, 1.7);
	     tree.add(12, 1.5);
	     tree.add(37, 1.2);
	     tree.add(43, 1.7);
	     tree.add(30, 1.5);
	     tree.add(33, 1.2);
	     tree.add(87, 1.7);
	     tree.add(93, 1.5);
	     tree.add(97, 1.5);
	     
	     tree.leftTraversal(tree.getRoot());
	     System.out.println();

	     tree.delete(30);
	     
	     tree.centerTraversal(tree.getRoot());
	     System.out.println();
	     
	     tree.rightTraversal(tree.getRoot());
	     System.out.println();
	     
	 }
}

package Tree;

public class Node<I extends Comparable<I> ,V> {
	//节点的关键字
	private I index;
	
	//节点的值
	private V value;
	
	private Node<I,V> left;
	
	private Node<I,V> right;

	public Node(){
	}

	public Node(I index,V value){
		this(index,value,null,null);
	}
	
	public Node(I index,V value,Node<I,V> left,Node<I,V> right){
		this.index = index;
		this.value = http://www.mamicode.com/value;>