java语言实现红黑树 仅仅实现了插入算法

package cn.itcast.shujujiegou.tree;

/**
* Created by likailong on 2016/10/13.
*/
public class RedBlackTree<T extends Comparable<? super T>> {
private RedBlackNode<T> header;
private RedBlackNode<T> nullNode;
private static final int RED=0;
private static final int BLACK=1;

public boolean isEmpty() {
return header==nullNode;
}

private static class RedBlackNode <T>{
T element;
int color;
RedBlackNode<T> left;
RedBlackNode<T> right;
RedBlackNode(T theElement){
this(theElement,null,null);
}
RedBlackNode(T theElement,RedBlackNode<T> lt,RedBlackNode<T> rt){
element=theElement;
left=lt;
right=rt;
color= RedBlackTree.BLACK;
}

}
public RedBlackTree(){
nullNode=new RedBlackNode<T>(null);
nullNode.left=nullNode.right=nullNode;
header=new RedBlackNode<T>(null);
header.left=header.right=nullNode;
}
private RedBlackNode<T> rotate(T item,RedBlackNode<T> parent){
if(compare(item,parent)<0)
return parent.left=compare(item,parent.left)<0?rotateWithLeftChild(parent.left):rotateWithRightChild(parent.left);
else
return parent.right=compare(item,parent.right)<0?rotateWithLeftChild(parent.right):rotateWithRightChild(parent.right);
}

private RedBlackNode<T> rotateWithRightChild(RedBlackNode<T> k2) {
RedBlackNode<T> k1=k2.right;
k2.right=k1.left;
k1.right=k2;
return k1;
}

private RedBlackNode<T> rotateWithLeftChild(RedBlackNode<T> k2) {
RedBlackNode<T> k1=k2.left;
k2.left=k1.right;
k1.right=k2;
return k1;
}

private final int compare(T item,RedBlackNode<T> t ){
if(t==header)
return 1;
else
return item.compareTo(t.element);
}
private RedBlackNode<T> current;
private RedBlackNode<T> parent;
private RedBlackNode<T> grand;
private RedBlackNode<T> great;
private void handleReorient(T item){
current.color=RED;
current.left.color=BLACK;
current.right.color=BLACK;
if(parent.color==RED){
grand.color=RED;
if((compare(item,grand)<0)!=(compare(item,parent)<0))
parent=rotate(item,grand);
current=rotate(item,great);
current.color=BLACK;
}
header.right.color=BLACK;
}
public void insert(T item){
current=parent=grand=header;
nullNode.element=item;
while (compare(item,current)!=0){
great=grand;
grand=parent;
parent=current;
current=compare(item,current)<0?current.left:current.right;
if(current.left.color==RED&¤t.right.color==RED){
handleReorient(item);
}
}
if(current!=nullNode)
return;
current=new RedBlackNode<>(item,nullNode,nullNode);
if(compare(item,parent)<0)
parent.left=current;
else
parent.right=current;
handleReorient(item);}
public void printTree(){
if(isEmpty()){
System.out.println("tree is empty");
}else
printTree(header.right);
}
private void printTree(RedBlackNode<T> t){
if(t!=nullNode){
printTree(t.left);
System.out.println(t.element);
printTree(t.right);
}
}
}