List directory and subdirectory files with listFiles

Question

Today I list through the code below the files that are in the directory passed by the parameter, but now I would like to list also the files that are in the subdirectories. I did some searches but I did not find anything that does not alter my structure much, also found that removing the isFile() I would, but it didn’t work.

void indexaArquivosDoDiretorio(File raiz) {
    FilenameFilter filtro = new FilenameFilter() {
        public boolean accept(File arquivo, String nome) {
            return nome.toLowerCase().endsWith(".pdf")
                    || nome.toLowerCase().endsWith(".odt")
                    || nome.toLowerCase().endsWith(".doc")
                    || nome.toLowerCase().endsWith(".docx")
                    || nome.toLowerCase().endsWith(".ppt")
                    || nome.toLowerCase().endsWith(".pptx")
                    || nome.toLowerCase().endsWith(".xls")
                    || nome.toLowerCase().endsWith(".txt")
                    || nome.toLowerCase().endsWith(".rtf");
        }
    };

    for (File arquivo : raiz.listFiles(filtro)) {
        if (arquivo.isFile()) {
            try {
                // Extrai o conteúdo do arquivo com o Tika;
                String textoExtraido = getTika().parseToString(arquivo);
                indexaArquivo(arquivo, textoExtraido);
                System.out.println(arquivo);
                i++;
            } catch (Exception e) {
                logger.error(e);
            }
        } else {
            indexaArquivosDoDiretorio(arquivo);
        }
    }
}

Answer 1

You can browse a directory structure, subdirectories and files with the method:

Path walkFileTree(Path start, FileVisitor<? super Path> visitor)

You need to specify the initial directory and implement the Filevisitor interface to tell you exactly what information should be shown when you go through the directory or file in question.

An example:

import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.BasicFileAttributes;

class MyFileVisitor extends SimpleFileVisitor<Path> {
    public FileVisitResult visitFile(Path path, BasicFileAttributes fileAttributes){
        System.out.println("Nome do arquivo:" + path.getFileName());
        return FileVisitResult.CONTINUE;
    }
    public FileVisitResult preVisitDirectory(Path path, BasicFileAttributes fileAttributes){
        System.out.println("----------Nome do diretório:" + path + "----------");
        return FileVisitResult.CONTINUE;
    }
}

public class Walk {
    public static void main(String[] args) {
        Path source = Paths.get("C:\\Users\\Math\\Desktop");
        try {
            Files.walkFileTree(source, new MyFileVisitor());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Source: Oracle Certified Professional Java SE 7 Programmer Exams 1Z0-804 and 1Z0-805: A Comprehensive OCPJP 7 Certification Guide (Expert’s Voice in Java)

Answer 2

I managed to solve my difficulty as follows: As I was already using a filter to show me the kind of files I was interested in, I came to the conclusion that the right place to check would be there. Then it dawned on me that a directory has no extension, so it would end up with "empty" the name, and that’s what I did. I added the line nome.toLowerCase().endsWith("") in my FilenameFilter and it worked.

That’s what the code looks like:

void indexaArquivosDoDiretorio(File raiz) {
        FilenameFilter filtro = new FilenameFilter() {
            public boolean accept(File arquivo, String nome) {
                return nome.toLowerCase().endsWith(".pdf")
                        || nome.toLowerCase().endsWith(".odt")
                        || nome.toLowerCase().endsWith(".doc")
                        || nome.toLowerCase().endsWith(".docx")
                        || nome.toLowerCase().endsWith(".ppt")
                        || nome.toLowerCase().endsWith(".pptx")
                        || nome.toLowerCase().endsWith(".xls")
                        || nome.toLowerCase().endsWith(".txt")
                        || nome.toLowerCase().endsWith(".rtf")
                        || nome.toLowerCase().endsWith("");
            }
        };

    for (File arquivo : raiz.listFiles(filtro)) {
        if (arquivo.isFile()) {
            try {
                // Extrai o conteúdo do arquivo com o Tika;
                String textoExtraido = getTika().parseToString(arquivo);
                indexaArquivo(arquivo, textoExtraido);
                System.out.println(arquivo);
                i++;
            } catch (Exception e) {
                logger.error(e);
            }
        } else {
            indexaArquivosDoDiretorio(arquivo);
        }
    }
}