Move file list between folders

Question

I have a method that copies files from one folder to another, then deletes the file. It suits me perfectly, but I wonder if there’s any way to do it without having to resort to InputStream and OutputStream, because I’ve had some problems with writing using these classes.

I saw that in java 8 there are functions that facilitate file operations using the class Files. It is possible to do this operation of "move files" more simply and directly, using other methods, such as the class Files?

Follow the current code:

private static void copiarArquivos() throws IOException {

    File src = new File(".");
    String dstPath = "C:\\java\\";
    File dst;

    File[] files = src.listFiles();

    for (File f : files) {
        String fileName = f.getName();

        if (fileName.contains("File")) {

            dst = new File(dstPath + fileName);
            InputStream in = new FileInputStream(f);
            OutputStream out = new FileOutputStream(dst);
            byte[] buf = new byte[1024];
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
            in.close();
            out.close();
            f.delete();
        }
    }
}

Answer 1

The first big change to make is just move the file and not copy it, that’s a huge waste of resources. You can just ask the operating system to rearrange your file system organization without even copying, or even moving one byte from it, just change its metadata to indicate that it is in another folder. You don’t need to know how it works, just know which method to call.

private static void copiarArquivos() throws IOException {
    File src = new File(".");
    String dstPath = "C:\\java\\";
    for (File f : src.listFiles()) {
        String fileName = f.getName();
        if (fileName.contains("File")) Files.move(f.toPath(), Paths.get(dstPath, fileName), REPLACE_EXISTING);
    }
}

I put in the Github for future reference.

Java 8 still allows use streams (examples) and the code can become more declarative. I do not always like, I think this is simple and understandable.

You can kill two variables, but I left.

Answer 2

Just out of curiosity in versions prior to 7.

Renaming:

import java.io.File;

public class Movendo {

  public static void main(String[] args) {
    try {
      File arquivo = new File("C:/pasta1/arquivo.txt");

      if (arquivo.renameTo(new File("C:/pastab/" + arquivo.getName()))) {
        System.out.println("Arquivo movido com sucesso!");
      } else {
        System.out.println("Falha ao mover arquivo!");
      }
    } catch (Exception e) {
      System.out.println("Falha ao mover arquivo!");
    }
  }
}