How to get all files from directory and sub directory with a given pattern

Question

I have a directory containing sub directories each one of this directories has a file called *.properties

I want to search for these files with java

Thanks

Answer 1

You can recursively call this method

File dir = new File("C:/");
File [] files = dir.listFiles(new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
    return name.endsWith(".properties");
    }
});

Alternately you use Java 7 Files.walkTree method and filter as described here .

Answer 2

See the java tutorial Walking the File Tree :

Do you need to create an application that will recursively visit all the files in a file tree? Perhaps you need to delete every .class file in a tree, or find every file that hasn't been accessed in the last year. You can do so with the FileVisitor interface.

In particular see the Finding Files example:

import java.io.*;
import java.nio.file.*;
import java.nio.file.attribute.*;
import static java.nio.file.FileVisitResult.*;
import static java.nio.file.FileVisitOption.*;
import java.util.*;

/**
 * Sample code that finds files that
 * match the specified glob pattern.
 * For more information on what
 * constitutes a glob pattern, see
 * http://docs.oracle.com/javase/javatutorials/tutorial/essential/io/fileOps.html#glob
 *
 * The file or directories that match
 * the pattern are printed to
 * standard out.  The number of
 * matches is also printed.
 *
 * When executing this application,
 * you must put the glob pattern
 * in quotes, so the shell will not
 * expand any wild cards:
 *     java Find . -name "*.java"
 */

public class Find {

    /**
     * A {@code FileVisitor} that finds
     * all files that match the
     * specified pattern.
     */
    public static class Finder
        extends SimpleFileVisitor<Path> {

        private final PathMatcher matcher;
        private int numMatches = 0;

        Finder(String pattern) {
            matcher = FileSystems.getDefault()
                    .getPathMatcher("glob:" + pattern);
        }

        // Compares the glob pattern against
        // the file or directory name.
        void find(Path file) {
            Path name = file.getFileName();
            if (name != null && matcher.matches(name)) {
                numMatches++;
                System.out.println(file);
            }
        }

        // Prints the total number of
        // matches to standard out.
        void done() {
            System.out.println("Matched: "
                + numMatches);
        }

        // Invoke the pattern matching
        // method on each file.
        @Override
        public FileVisitResult visitFile(Path file,
                BasicFileAttributes attrs) {
            find(file);
            return CONTINUE;
        }

        // Invoke the pattern matching
        // method on each directory.
        @Override
        public FileVisitResult preVisitDirectory(Path dir,
                BasicFileAttributes attrs) {
            find(dir);
            return CONTINUE;
        }

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

    static void usage() {
        System.err.println("java Find <path>" +
            " -name \"<glob_pattern>\"");
        System.exit(-1);
    }

    public static void main(String[] args)
        throws IOException {

        if (args.length < 3 || !args[1].equals("-name"))
            usage();

        Path startingDir = Paths.get(args[0]);
        String pattern = args[2];

        Finder finder = new Finder(pattern);
        Files.walkFileTree(startingDir, finder);
        finder.done();
    }
}

Answer 3

In addition to other answers:

Guava (since v15):

for (File f : Files.fileTreeTraverser().preOrderTraversal(rootDir)) {
    // filter and process
}

Commons IO:

for (File f : FileUtils.listFiles(rootDir, fileFilter, dirFilter)) {
    // process
}

Java 7:

Files.walkFileTree(rootDir, fileVisitor);