Hello, I'm getting quite flustered with this program and the errors are starting to get harder to debug. This is my tree.java file:
package TreePkg;
import java.io.FileNotFoundException;
import java.lang.SecurityException;
import java.util.Scanner;
import java.util.NoSuchElementException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.Serializable;
import java.io.EOFException;
class TreeNode<T extends Comparable <T>>
{
T data;
TreeNode<T> leftNode;
TreeNode<T> rightNode;
public TreeNode (T item){
data = item;
leftNode=rightNode=null;
}
}
public class Tree <T extends Comparable <T> & Serializable>
{
private TreeNode<T> root;
Scanner input = new Scanner(System.in);
public void Tree (){
root=null;
}
public void insertItem (T item){
if( root == null )
root = new TreeNode<T>( item );
else
insert(root, item);
}
private void insert (TreeNode<T> tree, T item){
if(item.compareTo(tree.data)<0)
{
if(tree.leftNode==null)
tree.leftNode = new TreeNode<T>(item);
else
insert(tree.leftNode, item);
}
else if(item.compareTo(tree.data)>0)
{
if(tree.rightNode==null)
tree.rightNode = new TreeNode<T>(item);
else
insert(tree.rightNode, item);
}
}
public void deleteItem (T item){
root = deleteNode(root, item);
}
private TreeNode<T> deleteNode (TreeNode<T> tree, T item){
if(tree != null){
if(item.compareTo(tree.data)<0)
tree.leftNode=deleteNode(tree.leftNode,item);
else if(item.compareTo(tree.data)>0)
tree.rightNode=deleteNode(tree.rightNode,item);
else if(item.compareTo(tree.data)==0)
if(tree.leftNode==null){
tree=tree.rightNode;
}
else if(tree.rightNode==null){
tree=tree.leftNode;
}
else{
TreeNode<T> tempNode=tree.leftNode;
while(tempNode.rightNode !=null)
tempNode=tempNode.rightNode;
tree.data=tempNode.data;
tree.leftNode=deleteNode(tree.leftNode,tempNode.data);
}
}
return tree;
}
////////preOrder///
public void preOrderTraversal(){
if(root !=null)
preOrderHelper(root);
else
System.out.println("\nTree is Empty\n");
}
private void preOrderHelper(TreeNode<T> tree){
if(tree==null)
return;
System.out.printf("%s",tree.data);
preOrderHelper(tree.leftNode);
preOrderHelper(tree.rightNode);
}
////////inOrder////
public void inOrderTraversal(){
if(root != null)
inOrderHelper(root);
else
System.out.println("\nTree is Empty\n");
}
private void inOrderHelper(TreeNode<T> tree){
if(tree==null)
return;
inOrderHelper(tree.leftNode);
System.out.printf("%s", tree.data);
inOrderHelper(tree.rightNode);
}
////////postOrder//
public void postOrderTraversal(){
if(root !=null)
postOrderHelper(root);
else
System.out.println("\nTree is Empty\n");
}
private void postOrderHelper(TreeNode<T> tree){
if(tree==null)
return;
postOrderHelper(tree.leftNode);
postOrderHelper(tree.rightNode);
System.out.printf("%s", tree.data);
}
// public boolean treeFormatTraversal()
// private boolean treeForamtHelper(TreeNode<T> tree, String indentSpaces)
public int lengthIs(){
return countNodes(root);
}
private int countNodes(TreeNode<T> tree){
if(tree==null)
return 0;
else
return countNodes(tree.leftNode)+countNodes(tree.rightNode)+1;
}
public boolean findItem(T item){
TreeNode<T> tree = root;
boolean found = false;
while(tree != null && found == false){
if(item.compareTo(tree.data)<0)
tree = tree.leftNode;
else if(item.compareTo(tree.data)>0)
tree = tree.rightNode;
else
found=true;
}
return found;
}
public boolean isEmpty(){
if(root==null)
return true;
else
return false;
}
public void clear(){
root=null;
}
public boolean saveToFile(){
String name;
System.out.print("Name of the output file: ");
name = input.nextLine();
try{
ObjectOutputStream output = new ObjectOutputStream(new FileOutputStream(name));
if(output==null){
System.out.println("\nOutput file did not open.\n");
}else{
output.close();
}
TreeNode<T> tree;
saveTree(output,tree);
}
catch(FileNotFoundException fnfe){
System.out.println("File not found.");
return false;
}
catch(SecurityException se){
System.out.println("No write access to this file.");
return false;
}
catch(Exception e){
System.out.println("Error opening file.");
return false;
}
return true;
}
private boolean saveTree(ObjectOutputStream output, TreeNode<T> tree){
output.writeObject(tree.data);
output.writeObject(tree.leftNode);
output.writeObject(tree.rightNode);
}
public boolean buildFromFile(){
String name;
boolean end = false;
System.out.print("Name of the input file: ");
name = input.nextLine();
ObjectInputStream ois = new ObjectInputStream(new FileInputStream(name));
try{
if(input==null){
System.out.println("\nInput file did not open.\n");
}
else if(input !=null){
ois.close();
}
}
catch(FileNotFoundException fnfe){
System.out.println("File not found.");
return false;
}
catch(NoSuchElementException nsee){
System.out.println("Invalid input. Please try again");
return false;
}
catch(IllegalStateException ise){
System.out.println("Illegal state.");
return false;
}
catch(EOFException eofe){
System.out.println("End of file.");
end=true;
return false;
}
catch(Exception e){
System.out.println("Error opening file.");
return false;
}
return true;
while(end==false){
System.out.println("Insert a value from the file.");
T obj = (T)ois.readObject();
insertItem(obj);
}
}
}The errors I've been getting are relatively similar:
Unreported exception java.io.IOException; must be caught or declared to be thrown
(all lines of the saveTree method)
Unreachable while statement
(end of program)
and then it says the ObjectOutputStream ois = new ObjectOutputStream(new FileInputStream(name)); is an unreported exception java.io.FileNotFoundException AND IOException...
I have no idea what this means as I have included try catch blocks in the appropriate methods.
PLEASE HALP!
Thanks,
Zach
