Develop Reference

Choosing a Random word from a text file

I'm trying to develop a hangman as an assignment, and is unable to get one random word from a Text file(which has various words and each word is separated with a space). I've written a code to get a random word, but unable to pick one words and replace it, with the sample string (String w = "this";) i have in the "Function()".
public String randomWord(String wordran) {
try {
BufferedReader reader = new BufferedReader(new FileReader("C:\\Users\\Admin\\Documents\\NetBeansProjects\\Main\\words.txt"));
String line = reader.readLine();
List<String> words = new ArrayList<String>();
while (line != null) {
String[] wordline = line.split(" ");
for (String word : wordline) {
words.add(word);
}
Random rand = new Random();
String randomWord1 = words.get(rand.nextInt(words.size()));
//System.out.println("rand word : " + randomWord1);
}
reader.close();
} catch (Exception e) {
}
return wordran;
}
public void function(){
int numGuesses = 10;
String w = randomWord();
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) {
System.out.println("You failed...:(");
break;
}
}
}
public static void main(String[] args) throws IOException {
Main ma = new Main();
ma.function();
loadWords();
// ma.randomWord();
}

There are three problems with your code:
You don't need to pass the parameter, String wordran to store the random word. A useful parameter can be String path through which you can pass the path of the file to the function.
You've missed reading the content from the file in the loop. You've read just the first line.
You haven't returned the random word which you have calculated by applying Random#nextInt.
On a side note, I recommend you use try-with-resources syntax to get rid of closing BufferedReader explicitly.
Given below is the correct code incorporating these comments:
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class Main {
public static void main(String[] args) throws IOException {
// Test
System.out.println(getRandomWord("C:\\Users\\Admin\\Documents\\NetBeansProjects\\Main\\words.txt"));
}
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()));
}
}

Search for multiline String in a text file

I have a text file from which i am trying to search for a String which has multiple lines. A single string i am able to search but i need multi line string to be searched.
I have tried to search for single line which is working fine.
public static void main(String[] args) throws IOException
{
File f1=new File("D:\\Test\\test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
while((s=br.readLine())!=null)
{
words=s.split("\n");
for (String word : words)
{
if (word.equals(input))
{
count++;
}
}
}
if(count!=0)
{
System.out.println("The given String "+input+ " is present for "+count+ " times ");
}
else
{
System.out.println("The given word is not present in the file");
}
fr.close();
}
And below are the file contents.
line one
line two
line three
line four

Use the StringBuilder for that, read every line from file and append them to StringBuilder with lineSeparator
StringBuilder lineInFile = new StringBuilder();
while((s=br.readLine()) != null){
lineInFile.append(s).append(System.lineSeparator());
}
Now check the searchString in lineInFile by using contains
StringBuilder searchString = new StringBuilder();
builder1.append("line one");
builder1.append(System.lineSeparator());
builder1.append("line two");
System.out.println(lineInFile.toString().contains(searchString));

More complicated solution from default C (code is based on code from book «The C programming language» )
final String searchFor = "Ich reiß der Puppe den Kopf ab\n" +
"Ja, ich reiß' ich der Puppe den Kopf ab";
int found = 0;
try {
String fileContent = new String(Files.readAllBytes(
new File("puppe-text").toPath()
));
int i, j, k;
for (i = 0; i < fileContent.length(); i++) {
for (k = i, j = 0; (fileContent.charAt(k++) == searchFor.charAt(j++)) && (j < searchFor.length());) {
// nothig
}
if (j == searchFor.length()) {
++found;
}
}
} catch (IOException ignore) {}
System.out.println(found);

Why don't you just normalize all the lines in the file to one string variable and then just count the number of occurrences of the input in the file. I have used Regex to count the occurrences but can be done in any custom way you find suitable.
public static void main(String[] args) throws IOException
{
File f1=new File("test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one line two";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
String fileStr = "";
while((s=br.readLine())!=null)
{
// Normalizing the whole file to be stored in one single variable
fileStr += s + " ";
}
// Now count the occurences
Pattern p = Pattern.compile(input);
Matcher m = p.matcher(fileStr);
while (m.find()) {
count++;
}
System.out.println(count);
fr.close();
}
Use StringBuilder class for efficient string concatenation.

Try with Scanner.findWithinHorizon()
String pathToFile = "/home/user/lines.txt";
String s1 = "line two";
String s2 = "line three";
String pattern = String.join(System.lineSeparator(), s1, s2);
int count = 0;
try (Scanner scanner = new Scanner(new FileInputStream(pathToFile))) {
while (scanner.hasNext()) {
String withinHorizon = scanner.findWithinHorizon(pattern, pattern.length());
if (withinHorizon != null) {
count++;
} else {
scanner.nextLine();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
System.out.println(count);

Try This,
public static void main(String[] args) throws IOException {
File f1 = new File("./src/test/test.txt");
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String input = "line one";
int count = 0;
String line;
while ((line = br.readLine()) != null) {
if (line.contains(input)) {
count++;
}
}
if (count != 0) {
System.out.println("The given String " + input + " is present for " + count + " times ");
} else {
System.out.println("The given word is not present in the file");
}
fr.close();
}

Converting ArrayLists in Java

I have the following code which counts and displays the number of times each word occurs in the whole text document.
try {
List<String> list = new ArrayList<String>();
int totalWords = 0;
int uniqueWords = 0;
File fr = new File("filename.txt");
Scanner sc = new Scanner(fr);
while (sc.hasNext()) {
String words = sc.next();
String[] space = words.split(" ");
for (int i = 0; i < space.length; i++) {
list.add(space[i]);
}
totalWords++;
}
System.out.println("Words with their frequency..");
Set<String> uniqueSet = new HashSet<String>(list);
for (String word : uniqueSet) {
System.out.println(word + ": " + Collections.frequency(list,word));
}
} catch (Exception e) {
System.out.println("File not found");
}
Is it possible to modify this code to make it so it only counts each occurrence once per line rather than in the entire document?

One can read the contents per line and then apply logic per line to count the words:
File fr = new File("filename.txt");
FileReader fileReader = new FileReader(file);
BufferedReader br = new BufferedReader(fileReader);
// Read the line in the file
String line = null;
while ((line = br.readLine()) != null) {
//Code to count the occurrences of the words
}

Yes. The Set data structure is very similar to the ArrayList, but with the key difference of having no duplicates.
So, just use a set instead.
In your while loop:
while (sc.hasNext()) {
String words = sc.next();
String[] space = words.split(" ");
//convert space arraylist -> set
Set<String> set = new HashSet<String>(Arrays.asList(space));
for (int i = 0; i < set.length; i++) {
list.add(set[i]);
}
totalWords++;
}
Rest of the code should remain the same.

file handling concept with spliting files

A folder contains number of text files like a.txt, b.txt, c.txt like that more than 30 files I need to search a particular string in the all files the output should come as follows:
a.txt contains your entered string
20
b.txt contains you entered string
30
And so on...
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("enter String");
String input = sc.nextLine();
double count = 0, countBuffer = 0, countLine = 0;
String lineNumber = ".txt";
File folder = new File("C://Users//Desktop//Santhosh.txt");
BufferedReader br;
String line = " ";
try {
br = new BufferedReader(new FileReader(folder));
try {
while ((line = br.readLine()) != null) {
countLine++;
//System.out.println(line);
String[] words = line.split(" ");
for (String word : words) {
if (word.equals(input)) {
count++;
countBuffer++;
}
}

#santhosh I think you want to search a text in files and count the occurrence of word according to file here is the program that do this:
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;
public class TextSearch {
File file;
FileReader reader;
BufferedReader buffReader;
String word;
Scanner scanner;
Map<String, Integer> counter = new TreeMap<String, Integer>();
public TextSearch() {
file = new File("D:\\Backup\\NP\\GN");// This Contain the 30 files
scanner = new Scanner(System.in);
System.out.println("Enter a word");
word = scanner.nextLine();
File[] listOfFiles = file.listFiles();
startSearch(listOfFiles);
Iterator<String> iterator = counter.keySet().iterator();
while (iterator.hasNext()) {
String key = iterator.next();
System.out.println(key + " contain this word " + word + " " + counter.get(key) + "times");
}
}
public void startSearch(File[] list) {
for (int i = 0; i < list.length; i++) {
if (list[i].isFile()) {
try {
reader = new FileReader(list[i]);
buffReader = new BufferedReader(reader);
String line = "";
while ((line = buffReader.readLine()) != null) {
if (line.contains(word)) {
if (counter.containsKey(list[i].getName())) {
Integer count = counter.get(list[i].getName());
count++;
counter.put(list[i].getName(), count);
} else {
counter.put(list[i].getName(), 1);
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
public static void main(String args[]) {
new TextSearch();
}
}

counting words of a file and storing it in array?

again. im gonna ask again about counting words and how to store it in array. So far, all i got is this.
Scanner sc = new Scanner(System.in);
int count;
void readFile() {
System.out.println("Gi navnet til filen: ");
String filNavn = sc.next();
try{
File k = new File(filNavn);
Scanner sc2 = new Scanner(k);
count = 0;
while(sc2.hasNext()) {
count++;
sc2.next();
}
Scanner sc3 = new Scanner(k);
String a[] = new String[count];
for(int i = 0;i<count;i++) {
a[i] =sc3.next();
if ( i == count -1 ) {
System.out.print(a[i] + "\n");
}else{
System.out.print(a[i] + " ");
}
}
System.out.println("Number of words: " + count);
}catch(FileNotFoundException e) {
my code works. but my question is, is there a more simple way to this? And the other question is how do i count the unique words out of the total words in a given file without using hashmap and arraylist.

Heres a simpler way to go about it:
public static void main(String[] args){
File f= new File(filename);
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(f)));
String line = null;
String[] res;
while((line = br.readLine())!= null ){
String[] tokens = line.split("\\s+");
String[] both = ArrayUtils.addAll(res, tokens);
}
}