"I'm not able to get out a tree output from this program. Please can someone help me to resolve the issue?" Here is the code:

import javax.swing.*;

import java.awt.Component;

import java.awt.event.ActionEvent;

import java.io.IOException;

public class BinarySearchTreeMain {

private JRadioButton IsBalancedRadioButton;

ButtonGroup buttonGroup = new ButtonGroup();

private JTextField expressionEntryField, expressionResultField;

private JRadioButton InorderRadioButton;

private Component IsFullButton;

public static void main(String[] args) throws IOException {

BinarySearchTreeMain binarySearch = new BinarySearchTreeMain();

binarySearch.instantiateGui();

}

private void instantiateGui() {

JFrame window = new JFrame("Binary Tree Categorizer");

window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JPanel panel = (JPanel) window.getContentPane();

window.setLayout(null);

JLabel promptLabel = new JLabel("Enter Tree");

promptLabel.setBounds(25, 15, 100, 20);

panel.add(promptLabel);

JLabel resultLabel = new JLabel("Output");

resultLabel.setBounds(25, 70, 100, 20);

panel.add(resultLabel);

expressionEntryField = new JTextField("", 30);

expressionEntryField.setBounds(125, 15, 350, 20);

panel.add(expressionEntryField);

expressionResultField = new JTextField("", 30);

expressionResultField.setBounds(125, 70, 350, 20);

panel.add(expressionResultField);

JButton MakeTreeButton = new JButton("MakeTree?");

MakeTreeButton.setBounds(175, 125, 125, 25);

MakeTreeButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, MakeTreeButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(MakeTreeButton);

JButton IsBalancedButton = new JButton("IsBalanced?");

IsBalancedButton.setBounds(175, 175, 125, 25);

IsBalancedButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, IsBalancedButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(IsBalancedButton);

JButton IsFullButton = new JButton("IsFull?");

IsFullButton.setBounds(175, 225, 125, 25);

IsFullButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, IsFullButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(IsFullButton);

JButton IsProperButton = new JButton("IsProper?");

IsProperButton.setBounds(175, 275, 125, 25);

IsProperButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, IsProperButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(IsProperButton);

JButton HeightButton = new JButton("Height?");

HeightButton.setBounds(175, 325, 125, 25);

HeightButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, HeightButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(HeightButton);

JButton NodesButton = new JButton("Nodes");

NodesButton.setBounds(175, 375, 125, 25);

NodesButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, NodesButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(NodesButton);

JButton InOrderButton = new JButton("InOrder?");

InOrderButton.setBounds(175, 425, 125, 25);

InOrderButton.addActionListener((ActionEvent e) -> {

try {

String entry = expressionEntryField.getText();

validateUserInput(entry);

validateUserSelections();

sortButtonAction(entry, InOrderButton);

} catch (Exception e1) {

System.out.println("Uncaught Exception: " + e1);

}

});

panel.add(InOrderButton);

window.getRootPane().setDefaultButton(MakeTreeButton);

window.setSize(500, 600);

window.setVisible(true);

}

private void validateUserSelections() {

}

private void sortButtonAction(String entry, AbstractButton MakeTreeRadioButton) throws Exception {

BinarySearchTree binarySearchTree;

String values[] = entry.split(" ");

// TODO: Optimize

if (MakeTreeRadioButton.isSelected()) {

binarySearchTree = new BinarySearchTree();

for (int i = 1; i < values.length; i++) {

if (values[i].split("/").length > 2) {

throw new Exception("Error. Malformed Fraction");

}

if (!values[i].contains("/")) {

Integer.parseInt(values[i]);

values[i] = values[i] + "/1";

}

binarySearchTree.bstInsert("int", (values[i]));

}

} else {

binarySearchTree = new BinarySearchTree(Integer.parseInt(values[0]));

for (int i = 1; i < values.length; i++) {

binarySearchTree.insert(Integer.parseInt(values[i]));

}

}

if (IsBalancedRadioButton.isSelected()) {

expressionResultField.setText(binarySearchTree.ascendingOrder(binarySearchTree.getRoot()));

} else {

expressionResultField.setText(binarySearchTree.ascendingOrder(binarySearchTree.getRoot()));

}

}

private void validateUserInput(String entry) throws Exception {

if (entry.equals("")) {

throw new Exception("Please Enter an Expression.");

}

for (int i = 0; i < entry.length(); i++) {

char c = entry.charAt(i);

if (!Character.isDigit(c) && c != '/' && !Character.isWhitespace(c)) {

throw new Exception("Error: Non numeric input detected.");

}

if (c == '/' && IsBalancedRadioButton.isSelected()) {

throw new Exception("Error: List of Integers contains a fraction.");

}

}

}

}

public class BinarySearchTree {

int key;

BinarySearchTree left, right;

public BinarySearchTree(int item) {

key = item;

left = right = null;

}

public BinarySearchTree() {

}

public void bstInsert(String string, String string2) {

}

public void insert(int parseInt) {

}

public Object getRoot() {

return null;

}

public String ascendingOrder(Object root) {

return null;

}

}

// Java program to introduce Binary Tree

class BinaryTree {

// Root of the Binary Tree

BinarySearchTree root;

// Constructors

BinaryTree(int key) {

root = new BinarySearchTree(key);

}

BinaryTree() {

root = null;

}

// tree.root = new Node(1);

// tree.root.left = new Node(2);

// tree.root.right = new Node(3);

// tree.root.left.left = new Node(4);

void printPostorder(BinarySearchTree node) {

if (node == null)

return;

// first recur on left subtree

printPostorder(node.left);

// then recur on right subtree

printPostorder(node.right);

// now deal with node

System.out.print(node.key + " ");

}

// Given a binary tree print this node in inorder

void printInorder(BinarySearchTree node) {

if (node == null)

return;

// first recur on left child

printInorder(node.left);

// the print the data of node

System.out.print(node.key + " ");

// now recur on right child

printInorder(node.right);

}

// Given a binary tree, print its nodes in preorder

void printPreorder(BinarySearchTree node) {

if (node == null)

return;

// first print data of node

System.out.print(node.key + " ");

// then recur on left subtree

printPreorder(node.left);

// now recur on right subtree

printPreorder(node.right);

}

public static void instantiateGui() {

}

}