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reading and writing files java

I have a float array which I stored in it some values from user input.
I have 2 methods one that saves the values stored in the array to a text file each value on a line and the second method rereads the values again and stores them in the array. for example, the user input was 1,2,3,4 I save them to a text file and then I read the same txt file now my array should display 8 elements 1,2,3,4,1,2,3,4.
the problem I'm having is that when I store these elements on the txt file it's storing them and adding like 100 zeros under them and when I'm calling the second method to reread these elements from the file it reads the zeros so when I'm displaying the elements in my array it's displaying 0,0,0,0 when it should display 1,2,3,4,1,2,3,4.
what might be causing me this problem?
public void saveValuesToFile(Scanner keyboard) {
try {
System.out.println("Enter name of file: ");
String fileName = keyboard.next();
File file = new File(fileName);
PrintWriter outputFile = new PrintWriter(file);
for(int i = 0; i < numbers.length; i++) {
outputFile.println(numbers[i]);
}
outputFile.close();
} catch (FileNotFoundException e) {
System.out.println("file dont exist");
e.printStackTrace();
}
}
public void readFromFile(Scanner keyboard) {
System.out.println("Enter file name");
String fileName = keyboard.next();
BufferedReader reader = null;
try {
reader = new BufferedReader (new FileReader(fileName));
String input = null;
while ((input = reader.readLine()) != null) {
for (int i = 0; i < numbers.length; i++) {
numbers[i] = Float.parseFloat(input);
}
}
}
catch (NumberFormatException | IOException e) {
e.printStackTrace();
}
}

You may check why the array is populated properly using additional println statement. In your version each element of array is populated with the same element read from the file. If you remove the inner loop, array will be populated properly.
int i=0;
while ((input = reader.readLine()) != null) {
numbers[i] = Float.parseFloat(input);
System.out.println((i) + "::"+numbers[i]);
i++;
}

Zeros are being added because you're saving numbers as float. If you store an integer 3 in a float variable it will be converted to a float equivalent which is 3.0
Also you don't need two loops here,
while ((input = reader.readLine()) != null) {
for (int i = 0; i < numbers.length; i++) {
numbers[i] = Float.parseFloat(input);
}
You can instead do following,
int i = 0;
while ((input = reader.readLine()) != null) {
numbers[i] = Float.parseFloat(input);
i++;
}
Following is a fully functional program of what you desire,
import java.util.Scanner;
import java.io.*;
public class Hello {
public static float[] numbers = {1,2,3,4,1,2,3,4};
public static void saveValuesToFile(Scanner keyboard) {
try {
System.out.println("Enter name of file: ");
String fileName = keyboard.next();
File file = new File(fileName);
PrintWriter outputFile = new PrintWriter(file);
for(int i = 0; i < numbers.length; i++) {
outputFile.println(numbers[i]);
}
outputFile.close();
} catch (FileNotFoundException e) {
System.out.println("file doesn't exist");
e.printStackTrace();
}
}
public static void readFromFile(Scanner keyboard) {
System.out.println("Enter file name");
String fileName = keyboard.next();
BufferedReader reader = null;
try {
reader = new BufferedReader (new FileReader(fileName));
String input = null;
int i = 0;
while ((input = reader.readLine()) != null) {
numbers[i] = Float.parseFloat(input);
i++;
}
for(int j = 0; j < numbers.length; j++) {
System.out.println(numbers[j]);
}
}
catch (NumberFormatException | IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
saveValuesToFile(scanner);
readFromFile(scanner);
}
}

combine two methods in Java together in this Java code

I want combine the two methods Just some error in my document parser, frequencyCounter and parseFiles thsi code.
I want all of frequencyCounter should be a function that should be executed from within parseFiles, and relevant information don't worry about the file's content should be passed to doSomething so that it knows what to print.
Right now I'm just keep messing up on how to put these two methods together, please give some advices
this is my main class:
public class Yolo {
public static void frodo() throws Exception {
int n; // number of keywords
Scanner sc = new Scanner(System.in);
System.out.println("number of keywords : ");
n = sc.nextInt();
for (int j = 0; j <= n; j++) {
Scanner scan = new Scanner(System.in);
System.out.println("give the testword : ");
String testWord = scan.next();
System.out.println(testWord);
File document = new File("path//to//doc1.txt");
boolean check = true;
try {
FileInputStream fstream = new FileInputStream(document);
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
strLine = br.readLine();
// Read File Line By Line
int count = 0;
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
String[] lineWords = strLine.split("\\s+");
// System.out.println(strLine);
count++;
}
}
System.out.println(testWord + "frequency: " + count);
br.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}

The code below gives you this output:
Professor frequency: 54
engineering frequency: 188
data frequency: 2
mining frequency: 2
research frequency: 9
Though this is only for doc1, you've to add a loop to iterate on all the 5 documents.
public class yolo {
public static void frodo() throws Exception {
String[] keywords = { "Professor" , "engineering" , "data" , "mining" , "research"};
for(int i=0; i< keywords.length; i++){
String testWord = keywords[i];
File document = new File("path//to//doc1.txt");
boolean check = true;
try {
FileInputStream fstream = new FileInputStream(document);
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
strLine = br.readLine();
// Read File Line By Line
int count = 0;
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
String[] lineWords = strLine.split("\\s+");
count++;
}
}
System.out.println(testWord + "frequency: " + count);
br.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
hope this helps!

Replace letters with *

Making a hangman style of game
I have the random word now. How do I replace the letters of the word with an asterix * so that when the program starts the word is shown as *.
I assume that when someone inputs a letter for the hangman game you get the index of that character in the word and then replace the corresponding *.
public class JavaApplication10 {
public static String[] wordArray = new String[1];
public static String file_dir = "Animals.txt";
public static String selectedWord = "";
public static char[] wordCharacter = new char[1];
Scanner sc = new Scanner(System.in);
public static void main(String[] args) throws IOException {
wordArray = get_word(file_dir);
selectedWord = select_word(wordArray);
System.out.println(selectedWord);
}
public static String[] get_word(String file_dir) throws IOException {
FileReader fileReader = new FileReader(file_dir);
BufferedReader bufferedReader = new BufferedReader(fileReader);
List<String> lines = new ArrayList<String>();
String line = null;
while ((line = bufferedReader.readLine()) != null) {
lines.add(line);
}
bufferedReader.close();
return lines.toArray(new String[lines.size()]);
}
public static String select_word(String[] wordArray) {
Random rand = new Random();
int lines = Math.abs(rand.nextInt(wordArray.length)- 1);
return wordArray[lines];
}
}

If you know how many lines are there you could use Random method in java with a specific range to pick out a line at random.
Then you could read the file line-by-line till you reach that random line and print it.
// Open the file
FileInputStream fstream = new FileInputStream("testfile.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
int counter=0;
//While-loop -> Read File Line By Line till the end of file
//And will also terminate when the required line is printed
while ((strLine = br.readLine()) != null && counter!=randomValue){
counter++;
//You need to set randomValue using the Random method as suggested
if(counter==randomValue)
// Print the content on the console
System.out.println (strLine+"\n");
}
//Close the input stream
br.close();

Assuming Java 8:
// Loading ...
Random R = new Random(System.currentTimeMillis());
List<String> animals = Files.readAllLines(Paths.get(path));
// ...
// When using
String randomAnimal = animals.get(R.nextInt(animals.size()));

Answer of your first question :
First you have to get the total number of lines
Then you have to generate a random number between 1 and that total number.
Finally, get the required word
try {
InputStream is = new BufferedInputStream(new FileInputStream("D:\\test.txt"));
byte[] c = new byte[1024];
int count = 0;
int readChars = 0;
boolean empty = true;
while ((readChars = is.read(c)) != -1) {
empty = false;
for (int i = 0; i < readChars; ++i) {
if (c[i] == '\n') {
++count;
}
}
}
int noOfLines = count+1;
System.out.println(noOfLines);
Random random = new Random();
int randomInt = random.nextInt(noOfLines);
FileReader fr = new FileReader("D:\\test.txt");
BufferedReader bufferedReader =
new BufferedReader(fr);
String line = null;
int counter =1;
while((line = bufferedReader.readLine()) != null) {
if(counter == randomInt)
{
System.out.println(line); // This the word you want
}
counter++;
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
finally {
//is.close();
}

java read only integers from file

If I have a file that contains for example:
results1: 2, 4, 5, 6, 7, 8, 9
results2: 5, 3, 7, 2, 8, 5, 2
I want to add the integers from each line to a array. One array
for each line. How can I do this with code that does only read the integers?
Here's what I got this far
String data = null;
try {
Scanner in = new Scanner(new File(myFile));
while (in.hasNextLine()) {
data = in.nextLine();
numbers.add(data);
}
in.close();
} catch (Exception e) {
}

Easy.
One line per array, not two as you have it. New line after each one.
Read each line as a String, discard the leading "resultsX:", and split what remains at a delimiter of your choosing (e.g. comma). Parse each into an integer and add it to a List.
I don't think that leading "results1: " is adding any value. Why do you have that?

public static void main(String[] args) throws IOException {
BufferedReader reader=null;
try {
reader = new BufferedReader(new FileReader(new File("PATH TO FILE")));
// Only works if File allways contains at least two lines ... all lines after the second
// will be ignored
System.out.println(String.format("Array 1 : %s", Arrays.toString(stringArray2IntArray(readNextLine(reader)))));
System.out.println(String.format("Array 2 : %s", Arrays.toString(stringArray2IntArray(readNextLine(reader)))));
} finally {
if (reader!=null) {
reader.close();
}
}
}
private static Integer[] stringArray2IntArray(String[] numStrings) {
List<Integer> result = new ArrayList<Integer>();
for (int i = 0; i < numStrings.length; i++) {
result.add(Integer.parseInt(numStrings[i].trim()));
}
return result.toArray(new Integer[numStrings.length]);
}
private static String[] readNextLine(BufferedReader reader) throws IOException {
return reader.readLine().split(":")[1].split(",");
}

Assuming you have an input file, like this:
2,4,5,6,7,8,9
5,3,7,2,8,5,2
here is a code snippet to load it:
String firstLine = "";
String secondLine = "";
File file = new File("path/to/file");
try {
BufferedReader br = new BufferedReader(new FileReader(file));
firstLine = br.readLine();
secondLine = br.readLine();
} catch(Exception e){
e.printStackTrace();
}
String[] firstResult = firstLine.split(",");
String[] secondResult = secondLine.split(",");
int[] firstIntegers = new int[firstResult.length];
for(int i = 0; i <= firstResult.length ; i++){
firstIntegers[i] = Integer.parseInt(firstResult[i]);
}
int[] secondIntegers = new int[secondResult.length];
for(int i = 0; i <= secondResult.length ; i++){
firstIntegers[i] = Integer.parseInt(secondResult[i]);
}

Open the file with a BufferedReader br and then read it line by line.
Store each line in an int array and add all those int arrays to a list. At the end, this list will contain all the int arrays that we wanted, so iterate this list to do whatever you want to do next.
String filePath = "/path/to/file";
BufferedReader br = null;
List<Integer[]> arrays = new ArrayList<>(); //this contains all the arrays that you want
try {
br = new BufferedReader(new FileReader(filePath));
String line = null;
while ((line = br.readLine()) != null) {
line = line.substring(line.indexOf(":")+2); //this starts the line from the first number
String[] stringArray = line.split(", ");
Integer[] array = new Integer[stringArray.length];
for (int i = 0; i < stringArray.length; ++i) {
array[i] = Integer.parseInt(stringArray[i]);
}
arrays.add(array);
}
} catch (FileNotFoundException ex) {
System.err.println(ex);
} catch (IOException ex) {
System.err.println(ex);
} finally {
try {
br.close();
} catch (Exception ex) {
System.err.println(ex);
}
}
Since ArrayLists keep insertion order, then, e.g., arrays.get(3) will give you the array of the fourth line (if there is such a line) and arrays.size() will give you the number of lines (i.e., int arrays) that are stored.

How do you store each value separately using comma then they store into separate array?

A simple data file which contains
1908,Souths,Easts,Souths,Cumberland,Y,14,12,4000
1909,Souths,Balmain,Souths,Wests,N
Each line represents a season of premiership and has the following format: year, premiers, runners up, minor premiers, wooden spooners, Grand Final held, winning score,
losing score, crowd
I know how to store a data into an array and use the delimiter, but I am not exactly sure how to store EACH data item by a comma into separate arrays? Some suggestions and what particular code to be used would be nice.
UPDATE:
I just added the code but it still didn't work. Here's the code:
import java.io.*;
import java.util.Scanner;
public class GrandFinal {
public static Scanner file;
public static String[] array = new String[1000];
public static void main(String[] args) throws FileNotFoundException {
File myfile = new File("NRLdata.txt");
file = new Scanner (myfile);
Scanner s = file.useDelimiter(",");
int i = 0;
while (s.hasNext()) {
i++;
array[i] = s.next();
}
for(int j=0; j<array.length; j++) {
if(array[j] == null)
;
else if(array[j].contains("Y"))
System.out.println(array[j] + " ");
}
}
}

Here you go. Use ArrayList. Its dynamic and convenient.
BufferedReader br = null;
ArrayList<String> al = new ArrayList();
String line = "";
try {
br = new BufferedReader(new FileReader("NRLdata.txt"));
while ((line = br.readLine()) != null) {
al.add(line);
}
} catch (Exception e) {
e.printStackTrace();
}
for (int i = 0; i < al.size(); i++) {
System.out.println(al.get(i));
}
What does not work in your case ?
Because your season array is empty. You need to define the length, for ex:
private static String[] season = new String[5];
This is not right because you don't know how many lines you are going to store. Which is why I suggested you to Use ArrayList.

After working around a bit, I have come up with following code:
private static File file;
private static BufferedReader counterReader = null;
private static BufferedReader fileReader = null;
public static void main(String[] args) {
try {
file = new File("C:\\Users\\rohitd\\Desktop\\NRLdata.txt");
counterReader = new BufferedReader(new FileReader(file));
int numberOfLine = 0;
String line = null;
try {
while ((line = counterReader.readLine()) != null) {
numberOfLine++;
}
String[][] storeAnswer = new String[9][numberOfLine];
int counter = 0;
fileReader = new BufferedReader(new FileReader(file));
while ((line = fileReader.readLine()) != null) {
String[] temp = line.split(",");
for (int j = 0; j < temp.length; j++) {
storeAnswer[j][counter] = temp[j];
System.out.println(storeAnswer[j][counter]);
}
counter++;
}
} catch (IOException e) {
e.printStackTrace();
}
}
catch (FileNotFoundException e) {
System.out.println("Unable to read file");
}
}
I have added counterReader and fileReader; which are used for counting number of lines and then reading the actual lines. The storeAnswer 2d array contains the information you need.
I hope the answer is better now.