or some reason I keep getting an error  Exception in thread "main" java.lang.Error: Unresolved compilation problem: The method append(char) is undefined for the type StringBuilder   at StringBuilder.main(StringBuilder.java:19)

Please use the template provided below and make sure the output matches exactly.   import java.util.Scanner;import java.util.ArrayList; public class PhotoLineups {    // TODO: Write method to create and output all permutations of the list of names.   public static void printAllPermutations(ArrayList<String> permList, ArrayList<String> nameList) {      }    public static void main(String[] args) {      Scanner scnr = new Scanner(System.in);      ArrayList<String> nameList = new ArrayList<String>();      ArrayList<String> permList = new ArrayList<String>();      String name;            // TODO: Read in a list of names; stop when -1 is read. Then call recursive method.   }}

JAVA PROGRAM MODIFY THIS PROGRAM SO IT READS THE TEXT FILES IN HYPERGRADE. I HAVE PROVIDED THE INPUTS AND THE FAILED TEST CASE AS A SCREENSHOT. HERE IS THE WORKING CODE TO MODIFY:  import java.io.*;import java.util.*;public class NameSearcher {    private static List<String> loadFileToList(String filename) throws FileNotFoundException {        List<String> namesList = new ArrayList<>();        File file = new File(filename);        if (!file.exists()) {            throw new FileNotFoundException(filename);        }        try (Scanner scanner = new Scanner(file)) {            while (scanner.hasNextLine()) {                String line = scanner.nextLine().trim();                String[] names = line.split("\\s+");                for (String name : names) {                    namesList.add(name.toLowerCase());                }            }        }        return namesList;    }    private static Integer searchNameInList(String name, List<String> namesList) {…

I am trying to write a spell checker class from scratch in java, and a spell checker test program in main but I got stuck because public int quadraticProbing(String[] hashArray, int initial_index, int collision) beginning from line 256 of SpellCheckHashTable.java is throwing a NullPointerException in 3 places as shown below. Exception in thread "main" java.lang.NullPointerException        at SpellCheckHashTable.quadraticProbing(SpellCheckHashTable.java:265)        at SpellCheckHashTable.insert(SpellCheckHashTable.java:209)        at SpellCheckHashTableDemo.main(SpellCheckHashTableDemo.java:48) I am trying to have the class use OOP principles of encapsulation, private variables, and getter and setter methods. Apart from hashcode() my program would not use predefined hashing methods from java. The program will: Read a set of words W, from a words.txt file and store them in a hash table; Implement a spellCheck function that performs a spell check on a string s, entered by user at the…

I need help finding out what to put in the: encryptedArray[index] = encrypt(messageArray);//pass something to encrypt from the array System.out.print(messageArray);//print encrypted version portion of the coding as well as how to call the "encryptAll" method

This is a java question do what in the question says please and do it on your own dont plagarise or copy from other sites thank you

My problem is my code does not recognize the file path.   CODE:   Author.java package libraryDatabase; import java.util.Objects; public class Author { String firstName; public Author() { } String LastName; public Author(String firstName, String lastName) { this.firstName = firstName; LastName = lastName; } @java.lang.Override public java.lang.String toString() { return "Author{" + "firstName='" + firstName + '\'' + ", LastName='" + LastName + '\'' + '}'; } //this will be used for comparing two authors @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Author author = (Author) o; return Objects.equals(firstName, author.firstName) && Objects.equals(LastName, author.LastName); } //this will be used when we compare two authors in search method @Override public int hashCode() { return Objects.hash(firstName, LastName); } }   Book.java package libraryDatabase; public class Book { Author author; String…

How do I implement a file with sets of numbers, such as 0 4 2 6 0 9 1 5 to an adjacency matrix JAVA?

The code below gives the error : Exception in thread "main" java.lang.IllegalArgumentException: bound must be positive at java.base/java.util.Random.nextInt at the line code (arr[i]=rand.nextInt(high-low+1)+low). How to fix this??  public static int[] generateIntArray(int size, int low, int high){ Random rand = new Random(); int[] arr=new int[size]; for(int i=0;i<size;i++){ arr[i]=rand.nextInt(high-low+1)+low; } return arr; } }

Review the following code. What will be printed to the console when we run the program? Explain why. Be sure to include a discussion of exceptions in your explanation. import java.util.LinkedList; public class Main { public static void main(String[] args) { LinkedList heroes = new LinkedList(); heroes.addLast("Jubilee"); heroes.addLast("Jean Grey"); heroes.addLast("Wolverine"); try { System.out.println(heroes.get(0)); } catch (IndexOutOfBoundsException e) { System.out.println("Exception caught!"); } } }