[[oktatas:programozás:java|< Java]]

====== Java nio csomag ======

  * **Szerző:** Sallai András
  * Copyright (c) 2022, Sallai András
  * Licenc: [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]]
  * Web: https://szit.hu

===== Fájl olvasása =====

<code java App.java>
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

public class App {
    public static void readFile() {
        try {
            tryReadFile();
        } catch (IOException e) {
            System.err.println("Hiba! A fájl nem olvasható!");
        }
    }
    public static void tryReadFile() throws IOException {
        Path path = Paths.get("employees.txt");
        Charset cs = StandardCharsets.UTF_8;
        List<String> lines = Files.readAllLines(path, cs);
        lines.forEach( line -> {
            String[] rows = line.split(":");
            System.out.println(rows[0]);
        });
    }

    public static void main(String[] args) throws Exception {
        readFile();
    }
}

</code>

===== Írás fájlba =====

<code java App.java>
import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class App {    
    public static void writeFile() {
        try {
            tryWriteFile();
        } catch (IOException e) {
            System.err.println("Hiba! A fájl nem olvasható!");
        }
    }
    public static void tryWriteFile() throws IOException {
        Path path = Paths.get("adat.txt");
        Charset cs = StandardCharsets.UTF_8;
        
        BufferedWriter writer = Files.newBufferedWriter(path, cs);
        writer.write("Valami");
        writer.close();
        
    }

    public static void main(String[] args) throws Exception {
        writeFile();
    }
}
</code>