write in file java

@Test
public void givenUsingJava7_whenWritingToFile_thenCorrect() 
  throws IOException {
    String str = "Hello";
 
    Path path = Paths.get(fileName);
    byte[] strToBytes = str.getBytes();
 
    Files.write(path, strToBytes);
 
    String read = Files.readAllLines(path).get(0);
    assertEquals(str, read);
}
import java.io.File;  // Import the File class
import java.io.IOException;  // Import the IOException class to handle errors

public class CreateFile {
  public static void main(String[] args) {
    try {
      File myObj = new File("filename.txt");
      if (myObj.createNewFile()) {
        System.out.println("File created: " + myObj.getName());
      } else {
        System.out.println("File already exists.");
      }
    } catch (IOException e) {
      System.out.println("An error occurred.");
      e.printStackTrace();
    }
  }
}