Created the abstract class Application.java and JavaDocs.

src/Practice/Application.java

@@ -1,9 +1,130 @@
 package Practice;
 
+import java.util.Scanner;
+
+/**
+ * This class is used to implement the generic features and UI of the problems.
+ *
+ * @author Jonathan Turner
+ * @version Spring 2024
+ */
 public abstract class Application {
 
-    public void start() {
+    private final int numOfOptions;
+    private final String[] menuOptions;
 
+
+    /**
+     * Creates a new application with specified menu options.
+     *
+     * @precondition options != null && options.length > 1
+     * @postcondition a new application is created.
+     *
+     * @param options the options for the program.
+     */
+    public Application(String[] options) {
+        if (options == null || options.length == 0) {
+            throw new IllegalArgumentException("The options must be valid and options.length < 1.");
+        }
+        this.numOfOptions = options.length;
+        this.menuOptions = options;
     }
 
+
+    /**
+     * Used as the main sentential loop and loops until the exit option is selected.
+     *
+     * @precondition none
+     * @postcondition none
+     */
+    public void start() {
+        int option = this.getOption();
+        while (option != (this.numOfOptions+1)) {
+            this.executeOption(option);
+            option = this.getOption();
+        }
+    }
+
+    /**
+     * This method is used to handle the option being selected.
+     *
+     * @precondition 0 < option <= this.numOfOptions
+     * @postcondition none
+     *
+     * @param option the Option being executed.
+     */
+    public abstract void executeOption(int option);
+
+    protected String getString(String prompt, String prefix, String error) {
+        System.out.println(prompt);
+        System.out.print(prefix);
+        Scanner sc = new Scanner(System.in);
+        String input = sc.nextLine();
+
+        while (input == null || input.isEmpty()) {
+            System.out.println(error);
+            System.out.print(prefix);
+            input = sc.nextLine();
+        }
+
+        return input;
+    }
+
+    /**
+     * Gets user input to a number. A prompt must be provided prior to running this method.
+     * If the input was not an integer/(unable to be autoboxed), returns -1.
+     *
+     * @precondition none
+     * @postcondition none
+     *
+     * @return the integer input, if invalid -1.
+     */
+    protected int getIntegerInput() {
+        Scanner sc = new Scanner(System.in);
+        try {
+            String textInput = sc.nextLine();
+            return Integer.parseInt(textInput);
+        } catch (Exception e) {
+            return -1;
+        }
+    }
+
+    /**
+     * Displays the menu options.
+     *
+     * @precondition none
+     * @postcondition the menu is displayed.
+     */
+    private void displayMenu() {
+        System.out.println("-----------------MAIN MENU--------------");
+        for (int index = 0; index < this.numOfOptions; index++) {
+            System.out.println((index+1) + ". " + this.menuOptions[index]);
+        }
+        System.out.println("3. Exit program");
+        System.out.println();
+    }
+
+    /**
+     * Prints out the menu of options, asks for an input, and if that input is invalid it prints an error and
+     * prompts the user again for the input.
+     *
+     * @precondition none
+     * @postcondition none
+     *
+     * @return the option selected
+     */
+    private int getOption() {
+        this.displayMenu(); // Prints out the menu
+
+        // Asks for the option and begins the loop until a valid option is gathered.
+        System.out.print("Enter option number: ");
+        int input = getIntegerInput();
+        while (input < 1 || input > (this.numOfOptions+1)) { // Compares it to the valid options available.
+            System.out.println("\nPlease enter a valid input.");
+            System.out.print("Enter option number: ");
+            input = getIntegerInput();
+        }
+        System.out.println();
+        return input;
+    }
 }