use .split() for files. java

asgr 0
Viewed 47

I have a file and want to split the file line by line. But I do not want to create a new file each time. just store every line in an Array. the .split() method is exactly what I want but it can't be used for files.

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;

class Read{

    public static void main(String args[])
    {
        try{
            File datei = new File("file.txt");
            Scanner myReader = new Scanner(datei);
            String[] splitDatei = datei.split(System.lineSeparator());


            myReader.close();


        }catch(FileNotFoundException e){
            System.out.println("");
            e.printStackTrace();
        }
    }
}
split java arrays
2 Answers

There is java.nio.file.Files#readAllLines(java.nio.file.Path) method:

List<String> stringList = Files.readAllLines(Path.of("file.txt"));

or java.nio.file.Files#lines(java.nio.file.Path) (you can can get a stream and then convert it to an array):

try (Stream<String> stream = Files.lines(Path.of("file.txt"))) {
    String[] strings = stream.toArray(String[]::new);
} catch (IOException e) {
    //
}

Docs:

Files#readAllLines

Files#lines

star670

It doesn't even appear that you are making use of your scanner in the code that you linked.

If you need to use the Scanner to do it, then you can use a variation of the following code. Though I recommend using star67's solution followed by a .toArray(new String[0]); call.

List<String> lines = new ArrayList<>();
File datei = new File("file.txt");
Scanner myReader = new Scanner(datei);
while(myReader.hasNextLine())
{
    lines.add(myReader.nextLine());
}
myReader.close();
final String[] linesArray = lines.toArray(new String[0]);
Jake Henry0
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