Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;
import java.util.List;

public class WritingFilesDemo {

public static void main(String[] args) throws IOException {
        Path dir  = Path.of("output");
        Path file = dir.resolve("report.txt");

// Create directory tree
        Files.createDirectories(dir);

// --- Files.writeString (simple) ---
        Files.writeString(file, "=== Report ===
", StandardCharsets.UTF_8);

// --- Append with StandardOpenOption.APPEND ---
        Files.writeString(file, "Item 1: done
",
            StandardCharsets.UTF_8, StandardOpenOption.APPEND);

// --- Files.write with list of lines ---
        List<String> lines = List.of("Item 2: done", "Item 3: pending", "");
        Files.write(file, lines, StandardCharsets.UTF_8, StandardOpenOption.APPEND);

// --- BufferedWriter for large output ---
        Path bigFile = dir.resolve("big.txt");
        try (BufferedWriter writer =
                Files.newBufferedWriter(bigFile, StandardCharsets.UTF_8)) {
            for (int i = 1; i <= 5; i++) {
                writer.write("Record " + i + ": value=" + (i * 10));
                writer.newLine();
            }
        } // flush + close happens here

// Read back to verify
        System.out.println("report.txt:");
        Files.readAllLines(file).forEach(l -> System.out.println("  " + l));

// --- Path operations ---
        System.out.println("
big.txt size: " + Files.size(bigFile) + " bytes");
        System.out.println("Exists:       " + Files.exists(file));

// Cleanup
        Files.delete(bigFile);
        Files.delete(file);
        Files.delete(dir);
    }
}