Find files in directory that have one of two keywo

Question

My linux server has a directory that contains many other sub-directories, that contains files named with keywords. For example:

Dir1:
 -Dir1.1:
   -file-keyword11-keyword7-keyword9.txt
   -file-keyword2-keyword7-keyword97.txt
 -Dir1.2:
   -file-keyword4-keyword6-keyword9.txt
   -file-keyword2-keyword8-keyword3.txt
Dir2:
 -Dir2.1:
   -file-keyword5-keyword42-keyword2.txt
   -file-keyword8-keyword11-keyword9.txt

I need a to create a method that returns a list of all files containing one of two keywords. For example:

findFiles("keyword11", "keyword42");

Should return the following files of the previous example:

-file-keyword11-keyword7-keyword9.txt
-file-keyword5-keyword42-keyword2.txt
-file-keyword8-keyword11-keyword9.txt

I am thinking about creating a recursive method that tests if the name of each file contains one of the two keywords. But I am afraid about performance, because the directories have thousands of files and sub-directories. And there will be more and more files that will be created every day.

I would like to know what would be the right way to do it. Should I use file.getName().contains() method? Should I use regex? Or should I use a linux command like grep?

Answer 1

You can use FileVisitor, it's very convenient.

Here is the example:

public class FileVisitorTest {

    @Test
    public void test() throws Exception {
        String path = "D:\\downloads\\";
        findFiles(path,"apache", "Test");
    }

    public void findFiles(String path, String... keyWords) {
        try {
            Files.walkFileTree(Paths.get(path), new FileVisitor<Path>() {
                @Override
                public FileVisitResult preVisitDirectory(Path path, BasicFileAttributes fileAttributes) {
                    return FileVisitResult.CONTINUE;
                }

                public FileVisitResult visitFile(Path path, BasicFileAttributes fileAttributes) {
                    for (String keyWord : keyWords) {
                        if (path.getFileName() != null && path.getFileName().toFile().getName().contains(keyWord))
                            System.out.println("File name:" + path.getFileName());
                    }

                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
                    return FileVisitResult.CONTINUE;
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

If you want to do smth with directories, use preVisitDirectory and postVisitDirectory methods to do smth before and after you visit a directory.