Files and Paths

File Write Read

A small text file can be written, read back, and removed using Files helpers.

writeString Files.writeString stores text at a path, creating or replacing the file.
readString Files.readString loads the whole text file into a String.

File Write Read

score
FileWriteRead.java
Replay: real traced execution (multi-file project)
import java.nio.file.Files;
import java.nio.file.Path;

public class FileWriteRead {
    public static void main(String[] args) throws Exception {
        int score = 7;
        Path path = Path.of("java21_write_read.txt");
        String text = "score=" + score;

        Files.writeString(path, text);
        String loaded = Files.readString(path);
        Files.deleteIfExists(path);

        System.out.println(loaded);
    }
}

import java.nio.file.Files;
import java.nio.file.Path;

public class FileWriteRead {
    public static void main(String[] args) throws Exception {
        int score = 3;
        Path path = Path.of("java21_write_read.txt");
        String text = "score=" + score;

        Files.writeString(path, text);
        String loaded = Files.readString(path);
        Files.deleteIfExists(path);

        System.out.println(loaded);
    }
}

import java.nio.file.Files;
import java.nio.file.Path;

public class FileWriteRead {
    public static void main(String[] args) throws Exception {
        int score = 12;
        Path path = Path.of("java21_write_read.txt");
        String text = "score=" + score;

        Files.writeString(path, text);
        String loaded = Files.readString(path);
        Files.deleteIfExists(path);

        System.out.println(loaded);
    }
}

  1. score ← 7, path ← java21_write_read.txt, text ← score=7, loaded ← score=7

    4public class FileWriteRead {5    public static void main(String[] args) throws Exception {6        int score→ 7 = 7;  //@score=3, 127        Path path→ java21_write_read.txt = Path.of("java21_write_read.txt");8        String text→ score=7 = "score=" + score7;910        Files.writeString(pathjava21_write_read.txt, textscore=7);11        String loaded→ score=7 = Files.readString(pathjava21_write_read.txt);12        Files.deleteIfExists(pathjava21_write_read.txt);1314        System.out.println(loadedscore=7);15    }
    outputscore=7

  1. score ← 3, path ← java21_write_read.txt, text ← score=3, loaded ← score=3

    4public class FileWriteRead {5    public static void main(String[] args) throws Exception {6        int score→ 3 = 3;7        Path path→ java21_write_read.txt = Path.of("java21_write_read.txt");8        String text→ score=3 = "score=" + score3;910        Files.writeString(pathjava21_write_read.txt, textscore=3);11        String loaded→ score=3 = Files.readString(pathjava21_write_read.txt);12        Files.deleteIfExists(pathjava21_write_read.txt);1314        System.out.println(loadedscore=3);15    }
    outputscore=3

  1. score ← 12, path ← java21_write_read.txt, text ← score=12, loaded ← score=12

    4public class FileWriteRead {5    public static void main(String[] args) throws Exception {6        int score→ 12 = 12;7        Path path→ java21_write_read.txt = Path.of("java21_write_read.txt");8        String text→ score=12 = "score=" + score12;910        Files.writeString(pathjava21_write_read.txt, textscore=12);11        String loaded→ score=12 = Files.readString(pathjava21_write_read.txt);12        Files.deleteIfExists(pathjava21_write_read.txt);1314        System.out.println(loadedscore=12);15    }
    outputscore=12