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How to replace a word based on its length?

All words having the given length wordLength in the string sentence must be replaced with the word myWord. All parameters come from user input and may vary. I have tried this way but it only returns the initial string with the initial words.
Here is my source code:
package main;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
public static void main(String[] args) throws Exception {
String sentence = "";
int wordLength = 0;
String myWord = "";
InputStreamReader is = new InputStreamReader(System.in);
BufferedReader bis = new BufferedReader(is);
System.out.println("Text input: ");
sentence = bis.readLine();
System.out.println("Word lenth to replace");
wordLength = Integer.parseInt(bis.readLine());
System.out.println("Word to replace to");
myWord = bis.readLine();
Text myText = new Text(myWord, sentence, wordLength);
myText.changeSentence();
System.out.println("New string" + myText.getSentence());
}
}
class Text {
private String mySentence;
private int charNumber;
private String wordToChange;
private String newSentence = "1.";
public Text(String wordToChange, String mySentece, int charNumber) {
this.mySentence = mySentece;
this.wordToChange = wordToChange;
this.charNumber = charNumber;
}
public String getSentence() {
return newSentence;
}
public void changeSentence() {
int firstPos = 0;
int i;
for (i = 0; i < mySentence.length(); i++) {
if (mySentence.charAt(i) == ' ') {
if (i - firstPos == charNumber) {
newSentence = newSentence.concat(wordToChange + " ");
firstPos = i + 1;
} else {
newSentence = newSentence.concat(mySentence.substring(firstPos, i + 1));
firstPos = i + 1;
}
} else if (i == mySentence.length() - 1) {
if (i - firstPos == charNumber) {
newSentence = newSentence.concat(wordToChange + " ");
firstPos = i + 1;
} else {
newSentence = newSentence.concat(mySentence.substring(firstPos, i + 1));
firstPos = i + 1;
}
}
}
}
}

I changed your code a little bit:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Main {
public static void main(String[] args) {
String sentence = "";
int wordLenght = 0;
String myWord = "";
InputStreamReader is = new InputStreamReader(System.in);
BufferedReader bis = new BufferedReader(is);
try {
System.out.println("Text input: ");
sentence = bis.readLine();
System.out.println("Word lenth to replace");
wordLenght = Integer.parseInt(bis.readLine());
System.out.println("Word to replace to");
myWord = bis.readLine();
} catch (IOException e) {
e.printStackTrace();
}
Text myText = new Text(myWord, sentence, wordLenght);
System.out.println(myText.getChangeSentence());
}
}
class Text {
private String mySentence;
private int charNumber;
private String wordToChange;
private String newSentence = "1.";
public Text(String wordToChange, String mySentece, int charNumber) {
this.mySentence = mySentece;
this.wordToChange = wordToChange;
this.charNumber = charNumber;
}
public String getChangeSentence() {
String[] words = mySentence.split(" ");
for(int i = 0 ; i < words.length ; i++) {
if(words[i].length() == charNumber) {
words[i] = wordToChange;
}
}
for (String word : words) {
newSentence += word + " ";
}
return newSentence;
}
}
Input : This is a test
word length : 2
word to replace : ii
output: This ii a test

As I can see the only separator of words that is currently considered to appear in the input text is a single white space " ". If that's true, then the changeSentence method can be quite short. There is no need to do parse the sentence character by characted. Having in mind that the white space is a separator, you can simply split the sentence by the characted " " and collect them as words. After that you can just iterate through words and replace ones that lenght matches given input characters number. After that, you can just join words together with the previously used separator and that's it.
Examples if you want to try with loops
public void changeSentence() {
final String[] words = mySentence.split(" ");
for (int i = 0; i < words.length; i++) {
if (words[i].length() == charNumber) {
words[i] = wordToChange;
}
}
newSentence = String.join(" ", words);
}
or with regular expressions
public void changeSentence() {
String regex = "\\b\\w{" + charNumber+ "}\\b";
newSentence = mySentence.replaceAll(regex, wordToChange);
}
or with the stream API
public void changeSentence() {
newSentence = Arrays.stream(mySentence.split(" "))
.map(s -> s.length() == charNumber ? wordToChange : s)
.collect(Collectors.joining(" "));
}

How can i make my turn my text file to 40x40 matrix [closed]

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In my code i need to read my text file and create a 40x40 matrix however my array only reads the first line Here is my code;
String worldData = "world.txt";
File worldFile = new File(worldData);
int[][] worldArray = new int[40][40];
Scanner scanner = new Scanner(worldFile);
while (scanner.hasNextLine()) {
String allText = scanner.nextLine();
String[] allLines = allText.split(";");
for (int i = 0; i < worldArray.length; i++) {
for (int j = 0; j < worldArray[0].length; j++) {
worldArray[i][j] = Integer.parseInt(allLines[0]);
}
}

I hope the in-line comment may give you some hints:
while (scanner.hasNextLine()) {
// you read a single line once in the while loop
String allText = scanner.nextLine();
String[] allLines = allText.split(";");
// here, for every new coming line, the for loop starts
// from array[0][0], therefore, it overwrites all the existing
// data. Thus, finally, you have only the last line in your array.
for (int i = 0; i < worldArray.length; i++) {
for (int j = 0; j < worldArray[0].length; j++) {
worldArray[i][j] = Integer.parseInt(allLines[0]);
}
}

Assuming that every line contains a row of the world matrix, the for-i loop should read exactly one line.
Scanner scanner = new Scanner(worldFile);
for (int i = 0; i < worldArray.length; i++) {
if (!scanner.hasNextLine()) {
throw new IllegalArgumentException("There are only " + i
+ " lines of the 40 needed.");
}
String line = scanner.nextLine();
String[] cells = line.split(";");
if (cells.length != 40) {
throw new IllegalArgumentException("There are " + i
+ " cells instead of the 40 needed.");
}
for (int j = 0; j < worldArray[0].length; j++) {
worldArray[i][j] = Integer.parseInt(cells[j]);
}
}
Alternatively you can do without a Scanner:
String worldData = "world.txt";
Path worldFile = Paths.get(worldData);
List<String> lines = Files.readAllLines(worldFile, StandardCharsets.UTF_8);
if (lines.size() < 40) {
throw new IllegalArgumentException("There are only "
+ lines.size()
+ " lines of the 40 needed.");
}
for (int i = 0; i < worldArray.length; i++) {
String line = lines.get(i);
String[] cells = line.split(";");
if (cells.length != 40) {
throw new IllegalArgumentException("There are " + i
+ " cells instead of the 40 needed.");
}
for (int j = 0; j < worldArray[0].length; j++) {
worldArray[i][j] = Integer.parseInt(cells[j]);
}
}

Other answers are good. Here you can try this to reduce loop operations and easily get integers from file without parsing String to Integer. Use delimiter with scanner object.
String worldData = "world.txt";
File worldFile = new File(worldData);
int[][] worldArray = new int[40][40];
int i = 0; // For index of worldArray
Scanner scanner = new Scanner(worldFile).useDelimiter("[\\n;]");
while(sc.hasNextInt()) {
wA[i/40][i%40] = sc.nextInt();
i++;
/* Since worldArray is a square matrix, you can keep
incrementing i and divide i by 40 to get rows index and i%40 to get column index thus simplifying the code.*/
}

you can use BufferedReader to read line by line from the file
BufferedReader br = new BufferedReader(new FileReader("world.txt"));
String line = null;
while((line=br.readLine()) != null) {
// process your line
}
br.close();

Passing a parameter to another function

I wrote a code for hangman, and i want to pass the randomly guessed word(randomly guessed from a text file), to be passed to a function hangman() where i can get the length of the word. a random word will be guessed from the getRandomWord(String path) function and I have passed value obtained to function() But cannot seem to pass the and get the result.
public class Main {
public static void main(String[] args) throws IOException {
Main ma = new Main();
String stm= null;
loadWords();
//hangman(w);
function();
}
public static String[] loadWords() {
System.out.println("Loading words from file :");
try {
File myObj = new File("C:\\Users\\Admin\\Documents\\NetBeansProjects\\Main\\words.txt");
Scanner myReader = new Scanner(myObj);
while (myReader.hasNext()) {
String data = myReader.nextLine().toLowerCase();
String[] spl = data.split(" ");
System.out.println(spl.length + " words loaded");
return spl;
}
myReader.close();
} catch (FileNotFoundException e) {
System.out.println("An error occurred.");
e.printStackTrace();
}
return null;
// TODO: Fill in your code here
}
public static String getRandomWord(String path) throws IOException {
List<String> words = new ArrayList<String>();
try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
String line;
while ((line = reader.readLine()) != null) {
String[] wordline = line.split("\\s+");
for (String word : wordline) {
words.add(word);
}
}
}
Random rand = new Random();
return words.get(rand.nextInt(words.size()));
}
public static List< String> getRemainingLetters(ArrayList< String> lettersGuessed) {
String alpha = "abcdefghijklmnopqrstuvwxyz";
String[] alpha1 = alpha.split("");
ArrayList< String> alpha2 = new ArrayList<>(Arrays.asList(alpha1));
for (int i = 0; i < lettersGuessed.size(); i++) {
for (int j = 0; j < alpha2.size(); j++) {
if (alpha2.get(j).equals(lettersGuessed.get(i))) {
alpha2.remove(j);
break;
}
}
}
return alpha2;
}
public static void function() throws IOException {
int numGuesses = 5;
String w = getRandomWord("C:\\Users\\Admin\\Documents\\NetBeansProjects\\Main\\words.txt");
String[] word = w.split("");
ArrayList< String> wList = new ArrayList<>(Arrays.asList(word));
ArrayList< String> wAnswer = new ArrayList< String>(wList.size());
for (int i = 0; i < wList.size(); i++) {
wAnswer.add("_ ");
}
int left = wList.size();
Scanner scanner = new Scanner(System.in);
boolean notDone = true;
ArrayList< String> lettersGuessed = new ArrayList< String>();
while (notDone) {
System.out.println();
String sOut = "";
List< String> lettersLeft = getRemainingLetters(lettersGuessed);
for (String s : lettersLeft) {
sOut += s + " ";
}
System.out.println("Letters Left: " + sOut);
sOut = "";
for (int i = 0; i < wList.size(); i++) {
sOut += wAnswer.get(i);
}
System.out.println(sOut + " Guesses left:" + numGuesses);
System.out.print("Enter a letter(* exit): ");
String sIn = scanner.next();
numGuesses--;
if (sIn.equals("*")) {
break;
}
lettersGuessed.add(sIn);
for (int i = 0; i < wList.size(); i++) {
if (sIn.equals(wList.get(i))) {
wAnswer.set(i, sIn);
left--;
}
}
if (left == 0) {
System.out.println("Congradulations you guessed it!");
break;
}
if (numGuesses == 0) {
StringBuilder sb = new StringBuilder();
for (String string : wList) {
sb.append(string);
}
String stm = sb.toString();
System.out.println("Sorry you ran out of guesses, the word was: " + stm);
break;
}
}
}
public static void hangman(String word) {
System.out.println("Welcome to Hangman Ultimate Edition");
System.out.println("I am thinking of a word that is " + word.length() + " letters long");
System.out.println("-------------");
}
}

Problems in your code:
Not passing the random word to the methods, hangman and function.
Instead of re-using the random word obtained from the method, getRandomWord in main, you have called getRandomWord again in the method, hangman which will give you a different random word causing incosistency.
Given below is the corrected program with a sample run:
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.Scanner;
public class Main {
public static void main(String[] args) throws IOException {
String word = getRandomWord("C:\\Users\\Admin\\Documents\\NetBeansProjects\\Main\\words.txt");
hangman(word);
function(word);
}
public static String getRandomWord(String path) throws IOException {
List<String> words = new ArrayList<String>();
try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
String line;
while ((line = reader.readLine()) != null) {
String[] wordline = line.split("\\s+");
for (String word : wordline) {
words.add(word);
}
}
}
Random rand = new Random();
return words.get(rand.nextInt(words.size()));
}
public static List<String> getRemainingLetters(ArrayList<String> lettersGuessed) {
String alpha = "abcdefghijklmnopqrstuvwxyz";
String[] alpha1 = alpha.split("");
ArrayList<String> alpha2 = new ArrayList<>(Arrays.asList(alpha1));
for (int i = 0; i < lettersGuessed.size(); i++) {
for (int j = 0; j < alpha2.size(); j++) {
if (alpha2.get(j).equals(lettersGuessed.get(i))) {
alpha2.remove(j);
break;
}
}
}
return alpha2;
}
public static void function(String w) throws IOException {
// The available number of guesses = length of the random word
int numGuesses = w.length();
// Split the random word into letters
String[] word = w.split("");
ArrayList<String> wList = new ArrayList<>(Arrays.asList(word));
ArrayList<String> wAnswer = new ArrayList<String>(wList.size());
for (int i = 0; i < wList.size(); i++) {
wAnswer.add("_ ");
}
int left = wList.size();
Scanner scanner = new Scanner(System.in);
boolean notDone = true;
ArrayList<String> lettersGuessed = new ArrayList<String>();
while (notDone) {
System.out.println();
String sOut = "";
List<String> lettersLeft = getRemainingLetters(lettersGuessed);
for (String s : lettersLeft) {
sOut += s + " ";
}
System.out.println("Letters Left: " + sOut);
sOut = "";
for (int i = 0; i < wList.size(); i++) {
sOut += wAnswer.get(i);
}
System.out.println(sOut + " Guesses left:" + numGuesses);
System.out.print("Enter a letter(* exit): ");
String sIn = scanner.next();
numGuesses--;
if (sIn.equals("*")) {
break;
}
lettersGuessed.add(sIn);
for (int i = 0; i < wList.size(); i++) {
if (sIn.equals(wList.get(i))) {
wAnswer.set(i, sIn);
left--;
}
}
if (left == 0) {
System.out.println("Congradulations you guessed it!");
break;
}
if (numGuesses == 0) {
StringBuilder sb = new StringBuilder();
for (String string : wList) {
sb.append(string);
}
String stm = sb.toString();
System.out.println("Sorry you ran out of guesses, the word was: " + stm);
break;
}
}
}
public static void hangman(String word) {
System.out.println("Welcome to Hangman Ultimate Edition");
System.out.println("I am thinking of a word that is " + word.length() + " letters long");
System.out.println("-------------");
}
}
A sample run:
Welcome to Hangman Ultimate Edition
I am thinking of a word that is 3 letters long
-------------
Letters Left: a b c d e f g h i j k l m n o p q r s t u v w x y z
_ _ _ Guesses left:3
Enter a letter(* exit): c
Letters Left: a b d e f g h i j k l m n o p q r s t u v w x y z
_ _ _ Guesses left:2
Enter a letter(* exit): a
Letters Left: b d e f g h i j k l m n o p q r s t u v w x y z
_ _ _ Guesses left:1
Enter a letter(* exit): t
Sorry you ran out of guesses, the word was: fox

To make your existing code run, you should just clean up the main method:
remove unused code:
Main ma = new Main(); // no need to create an instance, you use only static methods
String stm= null; // not used anywhere
loadWords(); // not used, entire method may be removed:
// it reads words only in the first line
fix method function to have a String w parameter, move getting the random word out of this method.
Thus, resulting changes should be:
public static void main(String[] args) throws IOException {
String word = getRandomWord("C:\\Users\\Admin\\Documents\\NetBeansProjects\\Main\\words.txt");
hangman(word);
function(word);
}
public static void function(String w) throws IOException {
int numGuesses = 5;
String[] word = w.split("");
// ... the rest of this method remains as is
}

Set boolean to true, but filewriter still overwrites the file, any advice?

I have created a simple program that sorts integers in an input file using different algorithms. I also use filewriter to output results to another file. Unfortunately no matter how I change my code, file gets overridden. Any advice?
Been searching for answer on google and tried changing the way I input the syntax but nothing works.
important bits:
setting the writer up
try {
FileWriter fileWriter = new FileWriter ("Sorted output.txt");
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
outputting to the file
out.println("User's own data set sorted using bubble sort.");
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println("Sorted Array looks like this:" + Arrays.toString(intArrayBubble));
out.println(timeToSort + bubbleSortIs + bubbleTime + "ms");
it works fine, however its used in a do while loop, with nested if statements, and each one overrides the other.
Rest of code in case its required - UPDATED - still not working
import java.io.*;
import java.util.*;
import java.util.concurrent.TimeUnit;
public class PDD_Sorting {
public static void main (String [] pArgs)
{
//Array for a file
String[] FileOne;
FileOne = new String[0];
int optionOne = 1,
optionTwo = 2,
optionThree = 3,
secondaryOptionOne = 1,
secondaryOptionTwo = 2,
secondaryOptionThree = 3,
userSelection,
subUserSelection;
String unsortedArray = "Unsorted array is: ",
bubbleSort = "Sorted array using bubble sort: ",
selectionSort = "Sorted array using selection sort: ",
insertionSort = "Sorted array using insertion sort: ",
timeToSort = "Time needed to sort this array using ",
bubbleSortIs = "bubble sort is ",
selectionSortIs = "selection sort is ",
insertionSortIs = "insertion sort is ",
welcomeToSorter = "Welcome to the SORTER - program that can sort your txt files containing integeres in an ascending order!",
notFiles = "Integers, not files :)",
pleaseSelect = "Please select one of the following options, by enetering a number asociated with it.",
optionOneUserInput = "1. Sort your own data set - input your own set of data (integers, separated by colons, no spaces) into the Input file.",
optionTwoPredefined = "2. Use predetermind set of data to test the algorythms.",
optionThreeExit = "3. Exit the program.",
subMenuPleaseSelect = "Please select which algorythm would you like to use to sort this file.",
optionBubble = "(1) - Bubble Sort.",
optionSelection = "(2) - Selection Sort.",
optionInsertion = "(3) - Insertion Sort.",
usersDataBubble = "User's own data set sorted using bubble sort.",
sortedArrayLooks = "Sorted Array looks like this:",
msTime = "ms",
usersDataSelection = "User's own data set sorted using selection sort.",
usersDataInsertion = "User's own data set sorted using insertion sort.",
validOption = "Please enter a valid option i.e. 1,2 or 3",
lessThanZero = "If time shown in ms is 0, that means the time needed to conduct the sort is shorter than 1ms.",
fileCreated = "File created.",
terminatingProgram = "Terminating the program.",
unableToWriteFile = "Unable to write to file";
System.out.println(welcomeToSorter);
System.out.println(notFiles);
Scanner tInput = new Scanner (System.in);
try {
FileWriter fileWriter = new FileWriter ("Sorted output.txt");
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
do {
System.out.println(pleaseSelect);
System.out.println(optionOneUserInput);
System.out.println(optionTwoPredefined);
System.out.println(optionThreeExit);
// Scanner tInput = new Scanner (System.in);
userSelection = tInput.nextInt();
if (userSelection == optionOne) {
//System.out.println("Please enter a valid path for your file.");
String[] splitFile = null;
//String userFile = tInput.next();
FileOne = getAndPrepareFile(splitFile);
System.out.println(subMenuPleaseSelect);
System.out.println(optionBubble);
System.out.println(optionSelection);
System.out.println(optionInsertion);
subUserSelection = tInput.nextInt();
if (subUserSelection == secondaryOptionOne) {
int size = FileOne.length;
int [] intArrayBubble = new int [size];
for(int i=0; i<size; i++) {
intArrayBubble[i] = Integer.parseInt(FileOne[i]);
}
bubbleSort(intArrayBubble);
long bubbleTime = timeCount(intArrayBubble);
out.println(usersDataBubble);
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println(sortedArrayLooks + Arrays.toString(intArrayBubble));
out.println(timeToSort + bubbleSortIs + bubbleTime + msTime);
}
else if (subUserSelection == secondaryOptionTwo) {
int size2 = FileOne.length;
int [] intArraySelection = new int [size2];
for(int i=0; i<size2; i++) {
intArraySelection[i] = Integer.parseInt(FileOne[i]);
}
doSelectionSort(intArraySelection);
long selectionTime = timeCount(intArraySelection);
out.println(usersDataSelection);
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println(sortedArrayLooks + Arrays.toString(intArraySelection));
out.println(timeToSort + selectionSortIs + selectionTime + msTime);
}
else if (subUserSelection == secondaryOptionThree) {
int size3 = FileOne.length;
int [] intArrayInsertion = new int [size3];
for(int i=0; i<size3; i++) {
intArrayInsertion[i] = Integer.parseInt(FileOne[i]);
}
doInsertionSort(intArrayInsertion);
long insertionTime = timeCount(intArrayInsertion);
out.println(usersDataInsertion);
out.println(unsortedArray + Arrays.deepToString(FileOne));
out.println(sortedArrayLooks + Arrays.toString(intArrayInsertion));
out.println(timeToSort + insertionSortIs + insertionTime + msTime);
}
else {
System.out.println(validOption);
tInput.next();
}
}
else if (userSelection == optionTwo){
//file being prepared and loaded via function
String[] splitFilePredefined = null;
FileOne = getAndPrepareFilePredefined(splitFilePredefined);
//converting string array into int array so the method can sort it.
int size = FileOne.length;
int [] intArrayBubble = new int [size];
for(int i=0; i<size; i++) {
intArrayBubble[i] = Integer.parseInt(FileOne[i]);
}
int size2 = FileOne.length;
int [] intArraySelection = new int [size2];
for(int i=0; i<size2; i++) {
intArraySelection[i] = Integer.parseInt(FileOne[i]);
}
int size3 = FileOne.length;
int [] intArrayInsertion = new int [size3];
for(int i=0; i<size3; i++) {
intArrayInsertion[i] = Integer.parseInt(FileOne[i]);
}
//inserting pre-prepared int arrays into variables including a timecount method
int bubbleTime = timeCount(intArrayBubble);
int selectionTime = timeCount(intArraySelection);
int insertionTime = timeCount(intArrayInsertion);
//sorting array using various sorts
bubbleSort(intArrayBubble);
doSelectionSort(intArraySelection);
doInsertionSort(intArrayInsertion);
//out.println("Sorted arrray using insertion sort looks like this: " + Arrays.toString(intArrayInsertion));
out.println(timeToSort + bubbleSortIs + bubbleTime + "ms");
out.println(timeToSort + selectionSortIs + selectionTime + "ms");
out.println(timeToSort + insertionSortIs + insertionTime + "ms");
out.println(lessThanZero);
System.out.println(fileCreated);
}
else if (userSelection == optionThree){
System.out.println(terminatingProgram);
System.exit(0);
}
else {
System.out.println(validOption);
tInput.next();
}
out.flush();
out.close();
//tInput.close();
}while (userSelection != optionThree);
}
catch (Exception e)
{
System.out.println(unableToWriteFile);
tInput.next();
}
tInput.close();
}//end main
//method that fetches the file from predefined, hardcoded location and removes comas, esentially prepares the file for the next phase
private static String[] getAndPrepareFile (String[] splitFile)
{
Scanner fileIn = null;
try
{
fileIn = new Scanner(new FileInputStream("C:\\Users\\Greg\\Documents\\Programming\\PDD - Assignment 1\\Input.txt"));
String fileNew = fileIn.next();
splitFile = fileNew.split(",");
//System.err.println(Arrays.toString(splitFile)); //Arrays.toString needed to print the array correctly, otherwise it prints the address of the object
fileIn.close();
}
catch (IOException e)
{
System.out.println("File not found.");
//System.exit(0);
}
return splitFile;
}
//as above but works for predefined file, that can be generated using randomNumber.java program
private static String[] getAndPrepareFilePredefined (String[] splitFilePredefined)
{
Scanner fileIn = null;
try
{
fileIn = new Scanner(new FileInputStream("C:\\Users\\Greg\\Documents\\Programming\\PDD - Assignment 1\\Generated input.txt"));
String fileNew = fileIn.next();
splitFilePredefined = fileNew.split(",");
//System.err.println(Arrays.toString(splitFile)); //Arrays.toString needed to print the array correctly, otherwise it prints the address of the object
fileIn.close();
}
catch (IOException e)
{
System.out.println("File not found.");
//System.exit(0);
}
return splitFilePredefined;
}
//method used to sort a file using bubble sort
private static void bubbleSort(int[] arr) {
int n = arr.length;
int temp = 0;
for(int i=0; i < n; i++){
for(int j=1; j < (n-i); j++){
if(arr[j-1] > arr[j]){
//swap elements
temp = arr[j-1];
arr[j-1] = arr[j];
arr[j] = temp;
}
}
}
}
//method used to sort a file using selection sort
private static int[] doSelectionSort(int[] arr){
for (int i = 0; i < arr.length - 1; i++)
{
int index = i;
for (int j = i + 1; j < arr.length; j++)
if (arr[j] < arr[index])
index = j;
int smallerNumber = arr[index];
arr[index] = arr[i];
arr[i] = smallerNumber;
}
return arr;
}
//method used to sort a file using sinsertion sort
private static int[] doInsertionSort(int[] input){
int temp;
for (int i = 1; i < input.length; i++) {
for(int j = i ; j > 0 ; j--){
if(input[j] < input[j-1]){
temp = input[j];
input[j] = input[j-1];
input[j-1] = temp;
}
}
}
return input;
}
//method used to calculate how much time has lapsed while using any of the given sort methods, outputs in ms, if less than 1 ms, outputs 0ms
private static int timeCount (int[] anArray)
{
long start = System.nanoTime();
Arrays.sort(anArray);
long end = System.nanoTime();
long timeInMillis = TimeUnit.MILLISECONDS.convert(end - start, TimeUnit.NANOSECONDS);
//System.out.println("Time spend in ms: " + timeInMillis);
return (int) timeInMillis;
}
}//end class
File gets constantly overridden, how do i stop this and make it add to file instead?

You don't need the first FileWriter fileWriter = new FileWriter("Sorted output.txt");; this is actually creating/overwriting the file, after which your PrintWriter opens it again for appending.
So, just change
// ... omitting beginning
try {
FileWriter fileWriter = new FileWriter ("Sorted output.txt");
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
do {
// ... omitting rest
to
// ... omitting beginning
try {
//BufferedWriter bufferedWriter = new BufferedWriter (fileWriter);
PrintWriter out = new PrintWriter (new FileWriter("Sorted output.txt", true));
do {
// ... omitting rest

Move out.close() outside the loop
else {
System.out.println("Please enter a valid option i.e. 1,2 or 3");
tInput.next();
}
out.flush();
/* THIS -> out.close(); <- THIS */
//tInput.close();
}while (userSelection != optionThree);
out.close();
}
I tried your code and your problem is not that the file is being overwritten, but that you are closing the outputstream in the first iteration.

Java ArrayIndexOutOfBoundsException keeps appearing while trying to find most occuring word in file

I am currently building a program which reads a file and prints the most occurring words and how many times each word appears like so:
package WordLookUp;
import java.util.*;
import java.io.*;
import java.lang.*;
public class WordLookUp {
private String[] mostWords;
private Scanner reader;
private String line;
private FileReader fr;
private BufferedReader br;
private List<String> original;
private String token = " ";
public WordLookUp(String file) throws Exception {
this.reader = new Scanner(new File(file));
this.original = new ArrayList<String>();
while (this.reader.hasNext()) { //reads file and stores it in string
this.token = this.reader.next();
this.original.add(token); //adds it to my arrayList
}
}
public void findMostOccurringWords() {
List<String> mostOccur = new ArrayList<String>();
List<Integer> count = new ArrayList<Integer>();
int counter = 0;
this.mostWords = this.token.split(" "); //storing read lines in mostWords arrayList
try {
for (int i = 0; i < original.size(); i++) {
if (this.original.equals(this.mostWords[i])) {
counter++; //increase counter
mostOccur.add(this.mostWords[i]);
count.add(counter);
}
}
for (int i = 0; i < mostOccur.size(); i++) {
System.out.println("Word: " + mostOccur.get(i) + " count: " + count.get(i));
}
} catch (ArrayIndexOutOfBoundsException ae) {
System.out.println("Illegal index");
}
}
}
package WordLookUp;
import java.util.*;
import java.io.*;
public class Main {
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
WordLookUp wL = new WordLookUp("tiny1.txt");
wL.findMostOccurringWords();
}
}
So when I keep running my file, it throws the exception I gave it: "Illegal index". I think it is my findMostOccuringWords method. To me the logic feels correct, but I don't know why it is throwing an ArrayIndexOutOfBoundsException. I tried playing with the for loops and tried to go from int i = 0 to i < mostOccur.size() - 1 but that is not working either. Is my logic wrong ? I am not allowed to use a hashmap and our professor gave us a hint that we can do this assignment easily with arrays and ArrayLists (no other built in functions, but regexes is highly recommended for use as well for the rest of the assignment). I put a private FileReader and BufferedReader up there as I am trying to see if they would work better or not. Thanks for the advice!

Can you try to use the following codes? I think your current algorithm is wrong.
public class WordLookUp {
private List<String> original;
private List<String> mostOccur = new ArrayList<String>();
private List<Integer> count = new ArrayList<Integer>();
public WordLookUp(String file) throws Exception {
try(Scanner reader = new Scanner(new File(file));){
this.original = new ArrayList<String>();
String token = " ";
while (reader.hasNext()) { //reads file and stores it in string
token = reader.next();
this.original.add(token); //adds it to my arrayList
findMostOccurringWords(token);
}
}
}
public void findMostOccurringWords(String token) {
int counter = 0;
String[] mostWords = token.split(" "); //storing read lines in mostWords arrayList
try {
for (int i = 0; i < mostWords.length; i++) {
for(int j = 0; j < this.original.size(); j++) {
if (original.get(j).equals(mostWords[i])) {
counter++; //increase counter
}
}
if (mostOccur.contains(mostWords[i])) {
count.set(mostOccur.indexOf(mostWords[i]),counter);
}else {
mostOccur.add(mostWords[i]);
count.add(counter);
}
}
} catch (ArrayIndexOutOfBoundsException ae) {
System.out.println("Illegal index");
}
}
public void count() {
for (int i = 0; i < mostOccur.size(); i++) {
System.out.println("Word: " + mostOccur.get(i) + " count: " + count.get(i));
}
}
}
public class Main {
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
WordLookUp wL = new WordLookUp("F:\\gc.log");
wL.count();
}
}

Here in this loop:
for (int i = 0; i < mostOccur.size(); i++) {
System.out.println("Word: " + mostOccur.get(i) + " count: " + count.get(i));
}
You check to make sure that i is within bounds for mostOccur but not count. I would add a condition to check to make sure it is in bounds. Such as:
for (int i = 0; i < mostOccur.size() && i < count.size(); i++) {
System.out.println("Word: " + mostOccur.get(i) + " count: " + count.get(i));
}