How to make a text file give you a string array

Question

I have a string array:

String[] word ={"atom","electron","oxyegn","explosion","combustion","flask","laser","molecule","ion","bond"};\

But i need to get this string from a text file that I would needed to have created. Please help me, I need this for my java assignment which it to build a hangman game (these are the words that are going to be guessed).

Answer 1

you can store these values in CSV (comma separated variables) in a file, like below.

atom,electron,oxyegn,explosion,combustion,flask,laser,molecule,ion,bond

While retrieving, you can read the contents of the file and split the line by comma like below

String s = ...read line form file...
String[] word = s.split(",");

Also, if you need to save some new values, you can do something like below (if you are using Java8)

String s = Stream.of(word).collect(Collectors.joining(","));
... save s in file...

• J.Dumitru: Hi, thnx for the help, do you need code for creating the file, I am pretty new to incorporating text files into java, so the more specific the better :)

Answer 2

Here's how I solved it:

package org.gooeybits.meltdown.utilities;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
 * Created by Yohanan Ben Abrahams.
 */
public class Main {
 private String[] words = null;
 public Main() {}
 public Main run() {
 this.words = loadWordsFromFile("/your/path/to/file.txt");
 return this;
 }
 private String[] loadWordsFromFile(String url) {
 String currentLine;
 List<String> words = new ArrayList<>();
 BufferedReader bufferedReader = null;
 try {
 bufferedReader = new BufferedReader(new FileReader(url));
 while ((currentLine = bufferedReader.readLine()) != null) {
 String[] split = currentLine.split("\\W");
 words.addAll(Arrays.asList(split));
 }
 } catch (IOException e) {
 System.err.print("Could not open the word file: " + e.getMessage());
 e.printStackTrace();
 } finally {
 try {
 if (bufferedReader != null) {
 bufferedReader.close();
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 return words.toArray(new String[words.size()]);
 }
 public String[] getWords() {
 return words;
 }
 public static void main(String[] args) {
 String[] words = new Main().run().getWords();
 for (String word : words) {
 System.out.println(word);
 }
 }
}

Answer 3

You can use a StreamTokenizer :

List<String> wordList = new ArrayList<String>();
Reader reader = new StringReader("atom electron ...");//replace this with a FileReader in you case
StreamTokenizer tokenizer = new StreamTokenizer(reader);
while(tokenizer.nextToken() != StreamTokenizer.TT_EOF){
 wordList.add(tokenizer.sval);
}
reader.close();

And if you really need an array :

String[] words = wordList.toArray(new String[worldList.size()];

• J.Dumitru: thank you for your help. Since i am just learning file readers could you specify an example of how I may do this step by step?
• Alexandre Cartapanis: replace the Reader reader = new StringReader("atom electron ..."); with Reader reader = new FileReader("/path/to/your/textfile");
• Alexandre Cartapanis: Note that StreamTokenizer is a part of the java standard API (java.io.StreamTokenizer)

Answer 4

If you do not wish to use any external imports, the following code would work:

public class TestStrings {
 private String[] namesList;
 public TestStrings() {
 String filePath = "path/to/file";
 this.namesList = readFile(filePath).split(",");
 }
 private static String readFile(String fileName) throws IOException {
 BufferedReader br = new BufferedReader(new FileReader(fileName));
 try {
 StringBuilder sb = new StringBuilder();
 String line = br.readLine();
 while (line != null) {
 sb.append(line);
 sb.append("\n");
 line = br.readLine();
 }
 return sb.toString();
 } finally {
 br.close();
 }
 }

• J.Dumitru: Thank you, how do i use the string array, nameslist, outside of the main ?
• Jaydev: Set the array to an instance variable within a constructor.
• J.Dumitru: I am not sure how to do that, still learning the basics, could you show me an example please :)