Display tree format directories

Question

I have this code here in JAVA where I need lists of folders and subfolders in tree format, but I can’t get it. Any help?

package Control;

import java.awt.Desktop;
import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class PercorreDir {


    public static StringBuffer buffer = new StringBuffer();

    public static int nespaço = 1;
    public static String espaço = "";

    public static StringBuffer percorre(File caminho){

        if(caminho.isDirectory()){

            buffer.append(espaço + caminho.getName()+"\n");

            for (File subpasta: caminho.listFiles()) {          

                for (int cta = 0; cta < nespaço; cta++){
                    espaço += "    ";
                }

                nespaço += 1;

                percorre(subpasta);
                }
        } else {
            nespaço = 0;
            espaço = "    ";

        }

        return buffer;

    }
}

Answer 1

If the problem is that whenever you find a file you "reset" the number of spaces to zero, which causes the next folder in the queue to be printed as if it were on the root. It is not necessary to do anything special in the case of files (since you do not want to treat them), instead I suggest increasing the number of spaces before going through the subfolder, and at the end decreasing again. Or better yet, don’t use a global variable (static), but pass the prefix of each folder as parameter:

public static StringBuffer percorre(File caminho){
    return percorre(caminho, "");
}

public static StringBuffer percorre(File caminho, String prefixo){

    if(caminho.isDirectory()){

        buffer.append(prefixo + caminho.getName()+"\n");

        String novoPrefixo = prefixo + "    ";

        for (File subpasta: caminho.listFiles()) {          
            percorre(subpasta, novoPrefixo);
        }
    }

    return buffer;

}