Develop Reference

taking in input from a file in java

i cannot for the life of me seem to take in the contents of this file, i keep getting No such elements exception on line 25, all help appreciate. heres a link to the file link
heres my code
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class practiceFinal {
public static void main(String[] args) {
String fileName = args[0];
int length = fileLength(fileName);
int[] array = new int[length];
String[] list = new String[length];
arrayPopulate(array, list, fileName);
for (int i = 0; i < array.length; i++) {
System.out.print(array[i]);
}
}
public static int fileLength(String fileName) {
File file = new File(fileName);
Scanner fileScan = new Scanner(fileName);
int counter = 0;
while (fileScan.hasNext()) {
fileScan.next();
counter++;
}
return counter;
}
public static void arrayPopulate(int[] array, String[] list, String fileName) {
File file = new File(fileName);
Scanner fileScan = null;
try {
fileScan = new Scanner(file);
} catch (FileNotFoundException e) {
System.out.println("details: " + e.getMessage());
}
for (int i = 0; i < array.length; i++) {
array[i] = fileScan.nextInt();
list[i] = fileScan.next();
}
}
}

There are a few problems here. First of all you are using fileScan.next(); to try and get the length of a file. This is going to give you 2 times the length because you are counting each token fileScan.next() grabs which will be first the number and then the letter.
Length of lines is 144 but when you calculate it, it returns 288.
So use fileScan.nextLine();, now some people have mentioned this but your program is still not going to work correctly because you passed Scanner fileScan = new Scanner(fileName); // mistake passed fileName instead of file
Here are the changes I made inside the fileLength() method:
File file = new File(fileName);
Scanner fileScan = new Scanner(file); // mistake passed fileName instead of file, changed from Scanner fileScan = new Scanner(fileName)
while (fileScan.hasNextLine()) {
fileScan.nextLine(); // changed from fileScan.next()
counter++;
}
Your output looks like:
84c89C11w71h110B96d61H92d10B3p40c97G117X13....
When you are printing the results, change the print statements to
System.out.print(array[i]);
System.out.print(" " + list[i]);
System.out.println();
Output now looks like:
84 c
89 C
11 w
71 h
....

Instead of using int length = fileLength(fileName); to find the length, use int length = fileName.length();

From the format of your file and your current code, it looks like length represents the number of "words" in the file. In your loop, you need to advance i by 2 instead of 1, since it consumes two "words" per iteration. This also means that each array is twice as long as it should be. Instantiate them with length/2.
for (int i = 0; i < array.length; i += 2) {
array[i] = fileScan.nextInt();
list[i] = fileScan.next();
}
Alternately, you could make length represent the number of lines in the file. To do that, use hasNextLine() and nextLine() in your counting loop. Then leave all of the rest of your code as-is.
while (fileScan.hasNextLine()) {
fileScan.nextLine();
counter++;
}
Additionally, make sure your Scanner is passed the proper parameters. A String is valid, but not for File I/O. You would need to first create a File object using the fileName.
Scanner fileScan = new Scanner(new File(fileName));

PrintWriter isn't writing the int values into the new file it created

So I'm supposed to read in a .txt file and then write a new one with the numbers backwards. For some reason only the number 0 is being printed in the new file when it should be 987654321987654321.
EDIT:
The input file reads:
123456789123456789
import java.io.*;
import java.util.*;
class Reverb
{
public static void main(String[] args) throws IOException
{
//System.out.println("Enter the name of the file you wish to open and reverse.");
Scanner kb = new Scanner(System.in);
//String s = kb.next();
Scanner inFile = new Scanner(new File("Untitled.txt"));
PrintWriter outFile = new PrintWriter("reversamundo2.txt");
int[] a = new int[18];
int index = 0;
while(inFile.hasNextInt())
{
a[index] = inFile.nextInt();
index++;
}
for(int i = index; i >= 0; i--)
{
outFile.println(a[i]);
}
inFile.close();
outFile.close();
}
}

You want to read character by character instead of a string and then reverse it. You can just read the String and reverse it using StringBuilder. So the code looks like:
Scanner inFile = new Scanner(new File("Untitled.txt"));
PrintWriter outFile = new PrintWriter("reversamundo2.txt");
// Read the first String from the input file.
String line = inFile.next();
// Create a StringBuilder object for that string, reverse it and return a string.
String reverse = new StringBuilder(line).reverse().toString();
// Print the reversed string to a new file.
outFile.print(reverse);

Input a text file in a two dimensional array with doubles

I'm new in Java.
I want to input a text file and create from it a two dimensional array the input is
like this
12,242 323,2324
23,4434 23,4534
23,434 56,3434
....
34,434 43,3443
I have tried
import java.util.Scanner;
import java.io.File;
import java.io.IOException;
public class InputText {
/**
* #param args the command line arguments
* #throws java.io.IOException
*/
public static void main(String[] args) throws IOException {
int i=0;
File file;
file = new File("file.txt");
Scanner read=new Scanner(file);
while (read.hasNextLine()) {
String line=read.nextLine();
System.out.println(line);
}
}
}
which gives me the input but I cannot insert this in an array I tried different ways like splitting it.
Any suggestions?
Sorry for not being clear. The input i mentioned is doubles seperated by spaces. Also the format i gave you is what i get after i run the part of the programm i wrote. What i see in the text file is the numbers seperated by spaces. I tried to implement your suggestion but nothing seemed to work. I'm really lost here....

If you want to split a line to two numbers you can use
string[] numbers = line.split("\\s+");
If you want to read a double with comma
NumberFormat format = NumberFormat.getInstance(Locale.FRANCE);
...
double d1 = format.parse(numbers[0]).doubleValue();
double d2 = format.parse(numbers[1]).doubleValue();
Personally i prefer to use scanner. In that case create it with
Scanner scanner = new Scanner(file);
while (scanner.hasNextLine()) {
Scanner scanner2 = new Scanner(scanner.nextLine()).useLocale(Locale.FRANCE);
if (!scanner2.hasNextDouble()){
System.out.println("Do not have a pair");
continue;
}
double d1 = scanner2.nextDouble();
if (!scanner2.hasNextDouble()){
System.out.println("Do not have a pair");
continue;
}
double d2 = scanner2.nextDouble();
//do something
}

After reading the line.. you will have to again split the string on ','. The split string need to be converted into interger. YOu can see as below:
import java.util.Scanner;
import java.io.File;
import java.io.IOException;
public class InputText {
/**
* #param args the command line arguments
* #throws java.io.IOException
*/
public static void main(String[] args) throws IOException {
int i = 0;
File file;
file = new File("file.txt");
Scanner read = new Scanner(file);
while (read.hasNextLine()) {
String line = read.nextLine();
String[] numbers = line.split(",");
for (i = 0; i < numbers.lenght; i++) {
String numStr = numbers[i];
String x=numStr.replaceAll("\\s+",""); //eleminate the space in any.
Double num = Double.valueOf(x);
System.out.println(" num is: " + num); //Here you can store the number in array.
}
}
}
}

Try to use something like that(add also try catch statement)
String line = "";
br = new BufferedReader(new FileReader("file.txt"));
int i=0;
while ((line = br.readLine()) != null) {
// use comma as separator
String[] lineArray= line.split(",");
for(int j=0;j<lineArray.length;j++){
my2DArray[i][j] = lineArray[j];
}
i++;
}
for(int i=0;i<my2DArray[0].length;i++){
for(int j=0;j<my2DArray[1].length;j++){
System.out.print(my2DArray[i][j] + " ");
}
}

Find specific word in text file and count it

someone can help me with code?
How to search in text file any word and count how many it were repeated?
For example test.txt:
hi
hola
hey
hi
bye
hoola
hi
And if I want to know how many times are repeated in test.txt word "Hi" program must say "3 times repeated"
I hope you understood what I want, thank you for answers.

public int countWord(String word, File file) {
int count = 0;
Scanner scanner = new Scanner(file);
while (scanner.hasNextLine()) {
String nextToken = scanner.next();
if (nextToken.equalsIgnoreCase(word))
count++;
}
return count;
}

HashMap h=new HashMap();
FileInputStream fin=new FileInputStream("d:\\file.txt");
BufferedReader br=new BufferedReader(new InputStreamReader(fin));
String n;
while((n=br.readLine())!=null)
{
if(h.containsKey(n))
{
int i=(Integer)h.get(n);
h.put(n,(i+1));
}
else
h.put(n, 1);
}
now iterate through this map to get the count for each word using each word as a key to the map values

Apache Commons - StringUtils.countMatches()

Use MultiSet collection from google guava library.
Multiset<String> wordsMultiset = HashMultiset.create();
Scanner scanner = new Scanner(fileName);
while (scanner.hasNextLine()) {
wordsMultiset.add(scanner.nextLine());
}
for(Multiset.Entry<String> entry : wordsMultiset ){
System.out.println("Word : "+entry.getElement()+" count -> "+entry.getCount());
}

package File1;
import java.io.BufferedReader;
import java.io.FileReader;
public class CountLineWordsDuplicateWords {
public static void main(String[] args) {
FileReader fr = null;
BufferedReader br =null;
String [] stringArray;
int counLine = 0;
int arrayLength ;
String s="";
String stringLine="";
try{
fr = new FileReader("F:/Line.txt");
br = new BufferedReader(fr);
while((s = br.readLine()) != null){
stringLine = stringLine + s;
stringLine = stringLine + " ";/*Add space*/
counLine ++;
}
System.out.println(stringLine);
stringArray = stringLine.split(" ");
arrayLength = stringArray.length;
System.out.println("The number of Words is "+arrayLength);
/*Duplicate String count code */
for (int i = 0; i < arrayLength; i++) {
int c = 1 ;
for (int j = i+1; j < arrayLength; j++) {
if(stringArray[i].equalsIgnoreCase(stringArray[j])){
c++;
for (int j2 = j; j2 < arrayLength; j2++) {
stringArray[j2] = stringArray[j2+1];
arrayLength = arrayLength - 1;
}
}//End of If block
}//End of Inner for block
System.out.println("The "+stringArray[i]+" present "+c+" times .");
}//End of Outer for block
System.out.println("The number of Line is "+counLine);
System.out.println();
fr.close();
br.close();
}catch (Exception e) {
e.printStackTrace();
}
}//End of main() method
}//End of class CountLineWordsDuplicateWords

package somePackage;
public static void main(String[] args) {
String path = ""; //ADD YOUR PATH HERE
String fileName = "test2.txt";
String testWord = "Macbeth"; //CHANGE THIS IF YOU WANT
int tLen = testWord.length();
int wordCntr = 0;
String file = path + fileName;
boolean check;
try{
FileInputStream fstream = new FileInputStream(file);
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
//Read File Line By Line
while((strLine = br.readLine()) != null){
//check to see whether testWord occurs at least once in the line of text
check = strLine.toLowerCase().contains(testWord.toLowerCase());
if(check){
//get the line, and parse its words into a String array
String[] lineWords = strLine.split("\\s+");
for(String w : lineWords){
//first see if the word is as least as long as the testWord
if(w.length() >= tLen){
/*
1) grab the specific word, minus whitespace
2) check to see whether the first part of it having same length
as testWord is equivalent to testWord, ignoring case
*/
String word = w.substring(0,tLen).trim();
if(word.equalsIgnoreCase(testWord)){
wordCntr++;
}
}
}
}
}
System.out.println("total is: " + wordCntr);
//Close the input stream
br.close();
} catch(Exception e){
e.printStackTrace();
}
}

public class Wordcount
{
public static void main(String[] args)
{
int count=0;
String str="hi this is is is line";
String []s1=str.split(" ");
for(int i=0;i<=s1.length-1;i++)
{
if(s1[i].equals("is"))
{
count++;
}
}
System.out.println(count);
}
}

You can read text file line by line. I assume that each line can contain more than one word. For each line, you call:
String[] words = line.split(" ");
for(int i=0; i<words.length; i++){
if(words[i].equalsIgnoreCase(searhedWord))
count++;
}

try using java.util.Scanner.
public int countWords(String w, String fileName) {
int count = 0;
Scanner scanner = new Scanner(inputFile);
scanner.useDelimiter("[^a-zA-Z]"); // non alphabets act as delimeters
String word = scanner.next();
if (word.equalsIgnoreCase(w))
count++;
return count;
}

Try it this way with Pattern and Matcher.
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Dem {
public static void main(String[] args){
try {
File f = new File("d://My.txt");
FileReader fr = new FileReader(f);
BufferedReader br = new BufferedReader(fr);
String s = new String();
while((s=br.readLine())!=null){
s = s + s;
}
int count = 0;
Pattern pat = Pattern.compile("it*");
Matcher mat = pat.matcher(s);
while(mat.find()){
if(mat.find()){
mat.start();
count++;
}
}
System.out.println(count);
} catch (Exception e) {
e.printStackTrace();
}
}
}

import java.io.*;
import java.util.*;
class filedemo
{
public static void main(String ar[])throws Exception
BufferedReader br=new BufferedReader(new FileReader("c:/file.txt"));
System.out.println("enter the string which you search");
Scanner ob=new Scanner(System.in);
String str=ob.next();
String str1="",str2="";
int count=0;
while((str1=br.readLine())!=null)
{
str2 +=str1;
}
int index = str2.indexOf(str);
while (index != -1) {
count++;
str2 = str2.substring(index + 1);
index = str2.indexOf(str);
}
System.out.println("Number of the occures="+count);
}
}

package com.test;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.Scanner;
public class Test {
public static void main(String[] args) throws Exception{
BufferedReader bf= new BufferedReader(new FileReader("src/test.txt"));
Scanner sc = new Scanner(System.in);
String W=sc.next();
//String regex ="[\\w"+W+"]";
int count=0;
//Pattern p = Pattern.compile();
String line=bf.readLine();
String s[];
do
{
s=line.split(" ");
for(String a:s)
{
if(a.contains(W))
count++;
}
line=bf.readLine();
}while(line!=null);
System.out.println(count);
}
}

public int occurrencesOfHi()
{
String newText = Text.replace("Hi","");
return (Text.length() - newText.length())/2;
}

How to tokenize an input file in java

i'm doing tokenizing a text file in java. I want to read an input file, tokenize it and write a certain character that has been tokenized into an output file. This is what i've done so far:
package org.apache.lucene.analysis;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
class StringProcessing {
// Create BufferedReader class instance
public static void main(String[] args) throws IOException {
InputStreamReader input = new InputStreamReader(System.in);
BufferedReader keyboardInput = new BufferedReader(input);
System.out.print("Please enter a java file name: ");
String filename = keyboardInput.readLine();
if (!filename.endsWith(".DAT")) {
System.out.println("This is not a DAT file.");
System.exit(0);
}
File File = new File(filename);
if (File.exists()) {
FileReader file = new FileReader(filename);
StreamTokenizer streamTokenizer = new StreamTokenizer(file);
int i = 0;
int numberOfTokensGenerated = 0;
while (i != StreamTokenizer.TT_EOF) {
i = streamTokenizer.nextToken();
numberOfTokensGenerated++;
}
// Output number of characters in the line
System.out.println("Number of tokens = " + numberOfTokensGenerated);
// Output tokens
for (int counter = 0; counter < numberOfTokensGenerated; counter++) {
char character = file.toString().charAt(counter);
if (character == ' ') { System.out.println(); } else { System.out.print(character); }
}
} else {
System.out.println("File does not exist!");
System.exit(0);
}
System.out.println("\n");
}//end main
}//end class
When i run this code, this is what i get:
Please enter a java file name: D://eclipse-java-helios-SR1-win32/LexractData.DAT
Number of tokens = 129
java.io.FileReader#19821fException in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 25
at java.lang.String.charAt(Unknown Source)
at org.apache.lucene.analysis.StringProcessing.main(StringProcessing.java:40)
The input file will look like this:
-K1 Account
--Op1 withdraw
---Param1 an
----Type Int
---Param2 amount
----Type Int
--Op2 deposit
---Param1 an
----Type Int
---Param2 Amount
----Type Int
--CA1 acNo
---Type Int
-K2 CheckAccount
--SC Account
--CA1 credit_limit
---Type Int
-K3 Customer
--CA1 name
---Type String
-K4 Transaction
--CA1 date
---Type Date
--CA2 time
---Type Time
-K5 CheckBook
-K6 Check
-K7 BalanceAccount
--SC Account
I just want to read the string which are starts with -K1, -K2, -K3, and so on... can anyone help me?

The problem is with this line --
char character = file.toString().charAt(counter);
file is a reference to a FileReader that does not implement toString() .. it calls Object.toString() which prints a reference around 25 characters long. Thats why your exception says OutofBoundsException at the 26th character.
To read the file correctly, you should wrap your filereader with a bufferedreader and then put each readline into a stringbuffer.
FileReader fr = new FileReader(filename);
BufferedReader br = new BufferedReader(fr);
StringBuilder sb = new StringBuilder();
String s;
while((s = br.readLine()) != null) {
sb.append(s);
}
// Now use sb.toString() instead of file.toString()

If you are wanting to tokenize the input file then the obvious choice is to use a Scanner. The Scanner class reads a given input stream, and can output either tokens or other scanned types (scanner.nextInt(), scanner.nextLine(), etc).
import java.util.Scanner;
import java.io.File;
import java.io.IOException;
public static void main(String[] args) throws IOException {
Scanner in = new Scanner(new File("filename.dat"));
while (in.hasNext) {
String s = in.next(); //get the next token in the file
// Now s contains a token from the file
}
}
Check out Oracle's documentation of the Scanner class for more info.

public class FileTokenize {
public static void main(String[] args) throws IOException {
final var lines = Files.readAllLines(Path.of("myfile.txt"));
FileWriter writer = new FileWriter( "output.txt");
String data = " ";
for (int i = 0; i < lines.size(); i++) {
data = lines.get(i);
StringTokenizer token = new StringTokenizer(data);
while (token.hasMoreElements()) {
writer.write(token.nextToken() + "\n");
}
}
writer.close();
}