Threaded Binary Tree: An alternative to find the successor and predecessor in linear time

Threaded Binary Tree

package ds.threadedTree;

class ThreadedNode {

int tData;
ThreadedNode left, right;
boolean leftThread, rightThread;

public ThreadedNode() {

}

public ThreadedNode(int tData, ThreadedNode left, ThreadedNode right,
boolean leftThread, boolean rightThread) {
this.tData = tData;
this.left = left;
this.right = right;
this.leftThread = leftThread;
this.rightThread = rightThread;
}

public ThreadedNode(boolean leftThread, boolean rightThread) {
this.tData = Integer.MAX_VALUE;
this.left = this;
this.right = this;
this.leftThread = leftThread;
this.rightThread = rightThread;
}

}

class ThreadedBSTree {
private ThreadedNode root;

public ThreadedBSTree() {
root = new ThreadedNode(true, false);
}

/*
* public int insert(int tData){ ThreadedNode newNode = findNode(root,
* tData); // if(newNode==null)
*
* }
*/

public ThreadedNode findNode(ThreadedNode current, int tData) {
if (current.tData < tData) {
if (current.rightThread)
return current;
return findNode(current.right, tData);
} else if (current.tData > tData) {
if (current.leftThread)
return current;
return findNode(current.left, tData);
} else
return null;
}

public void insert(int ele) {
ThreadedNode ptr = findNode(root, ele);

/** element already present **/
if (ptr == null)
return;

if (ptr.tData < ele) {
ThreadedNode nptr = new ThreadedNode(ele, ptr, ptr.right, true,
true);
ptr.right = nptr;
ptr.rightThread = false;
} else {
ThreadedNode nptr = new ThreadedNode(ele, ptr.left, ptr, true, true);
ptr.left = nptr;
ptr.leftThread = false;
}
}

public void inOrder() {
ThreadedNode temp = root;
for (;;) {
temp = insucc(temp);
if (temp == root)
break;
System.out.print(temp.tData + " ");
}
}

public ThreadedNode insucc(ThreadedNode tree) {
ThreadedNode temp;
temp = tree.right;
if (!tree.rightThread)
while (!temp.leftThread)
temp = temp.left;
return temp;
}

}

public class ThreadedTree {

public static void main(String args[]) {

ThreadedBSTree threadedBSTree = new ThreadedBSTree();

threadedBSTree.insert(12);
threadedBSTree.insert(9);
threadedBSTree.insert(22);
threadedBSTree.insert(16);
threadedBSTree.insert(32);
threadedBSTree.insert(30);
threadedBSTree.insert(42);

threadedBSTree.inOrder();

}

}