Search using Thread

I am looking for files using threads, the code I developed looks for the correct file, but it happens that it does not finish the execution when it finds, that is, if it does not find it, it continues to execute.

import java.io.File;
import java.util.Scanner;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import javax.swing.JOptionPane;

public class ProcuraArquivoThreadPool implements Runnable{

private static boolean achou;
private File pasta;
private String arquivo;
private Executor pool;

public ProcuraArquivoThreadPool(File pasta, String arquivo, Executor pool) {
    this.pasta = pasta;
    this.arquivo = arquivo;
    this.pool = pool;
}
public static void procura(String pasta, String arquivo, Executor pool) {
    achou = false;
    pool.execute(new ProcuraArquivoThreadPool(new File(pasta), arquivo, pool));

}

public void run() {
    if(achou){
        return;
    }

    for(File f : pasta.listFiles()){
        if(achou){
            break;
        } else if(f.isDirectory()){
            pool.execute(new ProcuraArquivoThreadPool (f, arquivo, pool));                               
        } else if(f.getName().equalsIgnoreCase(arquivo)){
            System.out.println("Achei: " + f.getPath());
            achou = true;
            break;
        }
    }
}

public static void main (String[] args){
    Scanner teclado = new Scanner(System.in);

    //System.out.println("Digite o caminho da Pasta");
    //String pasta = teclado.nextLine();
    System.out.println("Digite o arquivo a ser procurado");
    String arquivo = teclado.nextLine();

            String pasta = "C:/";

            System.out.println("Procurando......");

    ScheduledExecutorService threadpool = Executors.newScheduledThreadPool(4);

    procura(pasta, arquivo,threadpool);
}
}