I want to find all the txt files in directory and in the nested sub-directories. If found, I want to move that from one location to another.
The below code works fine, if i don't have any nested sub-directories.
The problem with the below code is, Once it find the nested directories it return the file only from that particular nested sub-directory.
But I want all the txt files in my directory ( parent and its nested sub-directories ).
public class FilesFindingInDirectory {
static ArrayList<File> al = new ArrayList<File>();
static File fileLocation = null;
public static void main(String[] args) throws IOException {
File filePath = new File("C:\\Users\\Downloads");
File[] listingAllFiles = filePath.listFiles();
ArrayList<File> allFiles = iterateOverFiles(listingAllFiles);
for (File file : allFiles) {
if(file != null) {
String fileName = file.getName();
String sourceFilepath = file.getAbsolutePath();
File targetFilePath = new File("D:\\TestFiles");
String targetPath = targetFilePath.getPath();
Files.move(Paths.get(sourceFilepath), Paths.get("D:\\TestFiles\\" + fileName));
}
}
}
public static ArrayList<File> iterateOverFiles(File[] files) {
for (File file : files) {
if (file.isDirectory()) {
iterateOverFiles(file.listFiles());// Calls same method again.
} else {
fileLocation = findFileswithTxtExtension(file);
if(fileLocation != null) {
System.out.println(fileLocation);
al.add(fileLocation);
}
}
}
return al;
}
public static File findFileswithTxtExtension(File file) {
if(file.getName().toLowerCase().endsWith("txt")) {
return file;
}
return null;
}
}
You're already using the nio Files API to move the files, why not using it to iterate over the files?
List<Path> txtFiles = Files.walk(Paths.get("C:\\Users\\Downloads"))
//use to string here, otherwise checking for path segments
.filter(p -> p.toString().endsWith(".txt"))
.collect(Collectors.toList());
If you don't need that intermediary list, you could as well run your move operation in a foreach terminal operation
Files.walk(Paths.get("C:\\Users\\Downloads"))
.filter(p -> p.toString().endsWith(".txt"))
.forEach(p -> {
try {
Files.move(p, Paths.get("D:\\TestFiles", p.getFileName().toString()));
} catch (IOException e) {
e.printStackTrace();
}
});
From your recursive function remove this line:
return al;
change this line to just call the recursive function:
ArrayList<File> allFiles = iterateOverFiles(listingAllFiles);
to
iterateOverFiles(listingAllFiles);
and finally change your for loop to iterate over the static field al.
for (File file : allFiles) {
to
for (File file : al) {
Explanation: There are numerous ways to write recursion for this problem. In this case you have a global variable for collecting the results. Each iteration should add to that global result, and simply return. At the end of all recursion calls, the global variable will contain all the results.
You are properly calling the function recursively, but you're then ignoring its return value. Instead, you should append it to the result list:
public static List<File> iterateOverFiles(File[] files) {
List<File> result = new ArrayList<>();
for (File file : files) {
if (file.isDirectory()) {
result.addAll(iterateOverFiles(file.listFiles()); // Here!
} else {
fileLocation = findFileswithTxtExtension(file);
if(fileLocation != null) {
result.add(fileLocation);
}
}
}
return result;
}
Just iterate over a directory, skipping any non-directory entries and entries that do not have the desired extension. Add all files with the correct extension to a result, and do that recursively for each directory.
public class FilesFindingInDirectory {
public static void main(String[] args) throws IOException {
File filePath = new File("C:\\Users\\Downloads");
Collection<File> allFiles = findFiles(filePath, ".txt");
allFiles.forEach(file -> {
String fileName = file.getName();
String sourceFilepath = file.getAbsolutePath();
File targetFilePath = new File("D:\\TestFiles");
String targetPath = targetFilePath.getPath();
Files.move(Paths.get(sourceFilepath), Paths.get("D:\\TestFiles\\" + fileName));
}
}
}
public static List<File> findFiles(File dir, String extension) {
File[] files = dir.listFiles(f -> f.isDirectory() || f.getName().toLowerCase().endsWith(extension);
ArrayList<File> result = new ArrayList<>();
if (files != null) {
for (File file : files) {
if (file.isDirectory()) {
result.addAll(findFiles(file, extension);
} else {
result.add(file);
}
}
return result;
}
}
I am searching for a sound file in a folder and want to know if the sound file exist may it be .mp3,.mp4,etc.I just want to make sure that the filename(without extension) exists.
eg.File searching /home/user/desktop/sound/a
return found if any of a.mp3 or a.mp4 or a.txt etc. exist.
I tried this:
File f=new File(fileLocationWithExtension);
if(f.exist())
return true;
else return false;
But here I have to pass the extension also otherwise its returning false always
To anyone who come here,this is the best way I figured out
public static void main(String[] args) {
File directory=new File(your directory location);//here /home/user/desktop/sound/
final String name=yourFileName; //here a;
String[] myFiles = directory.list(new FilenameFilter() {
public boolean accept(File directory, String fileName) {
if(fileName.lastIndexOf(".")==-1) return false;
if((fileName.substring(0, fileName.lastIndexOf("."))).equals(name))
return true;
else return false;
}
});
if(myFiles.length()>0)
System.Out.println("the file Exist");
}
Disadvantage:It will continue on searching even if the file is found which I never intended in my question.Any suggestion is welcome
This code will do the trick..
public static void listFiles() {
File f = new File("C:/"); // use here your file directory path
String[] allFiles = f.list(new MyFilter ());
for (String filez:allFiles ) {
System.out.println(filez);
}
}
}
class MyFilter implements FilenameFilter {
#Override
//return true if find a file named "a",change this name according to your file name
public boolean accept(final File dir, final String name) {
return ((name.startsWith("a") && name.endsWith(".jpg"))|(name.startsWith("a") && name.endsWith(".txt"))|(name.startsWith("a") && name.endsWith(".mp3")|(name.startsWith("a") && name.endsWith(".mp4"))));
}
}
Above code will find list of files which has name a.
I used 4 extensions here to test(.jpg,.mp3,.mp4,.txt).If you need more just add them in boolean accept() method.
EDIT :
Here is the most simplified version of what OP wants.
public static void filelist()
{
File folder = new File("C:/");
File[] listOfFiles = folder.listFiles();
for (File file : listOfFiles)
{
if (file.isFile())
{
String[] filename = file.getName().split("\\.(?=[^\\.]+$)"); //split filename from it's extension
if(filename[0].equalsIgnoreCase("a")) //matching defined filename
System.out.println("File exist: "+filename[0]+"."+filename[1]); // match occures.Apply any condition what you need
}
}
}
Output:
File exist: a.jpg //These files are in my C drive
File exist: a.png
File exist: a.rtf
File exist: a.txt
File exist: a.mp3
File exist: a.mp4
This code checks all the files of a path.It will split all filenames from their extensions.And last of all when a match occurs with defined filename then it will print that filename.
If you're looking for any file with name "a" regardless of the suffix, the glob that you're looking for is a{,.*}. The glob is the type of regular expression language used by shells and the Java API to match filenames. Since Java 7, Java has support for globs.
This Glob explained
{} introduces an alternative. The alternatives are separated with ,. Examples:
{foo,bar} matches the filenames foo and bar.
foo{1,2,3} matches the filenames foo1, foo2 and foo3.
foo{,bar} matches the filenames foo and foobar - an alternative can be empty.
foo{,.txt} matches the filenames foo and foo.txt.
* stands for any number of characters of any kind, including zero characters. Examples:
f* matches the filenames f, fa, faa, fb, fbb, fab, foo.txt - every file that's name starts with f.
The combination is possible. a{,.*} is the alternatives a and a.*, so it matches the filename a as well as every filename that starts with a., like a.txt.
A Java program that lists all files in the current directory which have "a" as their name regardless of the suffix looks like this:
import java.io.*;
import java.nio.file.*;
public class FileMatch {
public static void main(final String... args) throws IOException {
try (final DirectoryStream<Path> stream = Files.newDirectoryStream(Paths.get("."), "a{,.*}")) {
for (final Path entry : stream) {
System.out.println(entry);
}
}
}
}
or with Java 8:
import java.io.*;
import java.nio.file.*;
public class FileMatch {
public static void main(final String... args) throws IOException {
try (final DirectoryStream<Path> stream = Files.newDirectoryStream(Paths.get("."), "a{,.*}")) {
stream.forEach(System.out::println);
}
}
}
If you have the filename in a variable and you want to see whether it matches the given glob, you can use the FileSystem.getPathMatcher() method to obtain a PathMatcher that matches the glob, like this:
final FileSystem fileSystem = FileSystems.getDefault();
final PathMatcher pathMatcher = fileSystem.getPathMatcher("glob:a{,.*}");
final boolean matches = pathMatcher.matches(new File("a.txt").toPath());
You can try some thing like this
File folder = new File("D:\\DestFile");
File[] listOfFiles = folder.listFiles();
for (File file : listOfFiles) {
if (file.isFile()) {
System.out.println("found ."+file.getName().substring(file.getName().lastIndexOf('.')+1));
}
}
Try this:
File parentDirToSearchIn = new File("D:\\DestFile");
String fileNameToSearch = "a";
if (parentDirToSearchIn != null && parentDirToSearchIn.isDirectory()) {
String[] childFileNames = parentDirToSearchIn.list();
for (int i = 0; i < childFileNames.length; i++) {
String childFileName = childFileNames[i];
//Get actual file name i.e without any extensions..
final int lastIndexOfDot = childFileName.lastIndexOf(".");
if(lastIndexOfDot>0){
childFileName = childFileName.substring(0,lastIndexOfDot );
if(fileNameToSearch.equalsIgnoreCase(childFileName)){
System.out.println(childFileName);
}
}//otherwise it could be a directory or file without any extension!
}
}
You could make use of the SE 7 DirectoryStream class :
public List<File> scan(File file) throws IOException {
Path path = file.toPath();
try (DirectoryStream<Path> paths = Files.newDirectoryStream(path.getParent(), new FileNameFilter(path))) {
return collectFilesWithName(paths);
}
}
private List<File> collectFilesWithName(DirectoryStream<Path>paths) {
List<File> results = new ArrayList<>();
for (Path candidate : paths) {
results.add(candidate.toFile());
}
return results;
}
private class FileNameFilter implements DirectoryStream.Filter<Path> {
final String fileName;
public FileNameFilter(Path path) {
fileName = path.getFileName().toString();
}
#Override
public boolean accept(Path entry) throws IOException {
return Files.isRegularFile(entry) && fileName.equals(fileNameWithoutExtension(entry));
}
private String fileNameWithoutExtension(Path candidate) {
String name = candidate.getFileName().toString();
int extensionIndex = name.lastIndexOf('.');
return extensionIndex < 0 ? name : name.substring(0, extensionIndex);
}
}
This will return files with any extension, or even without extension, as long as the base file name matches the given File, and is in the same directory.
The FileNameFilter class makes the stream return only the matches you're interested in.
public static boolean everExisted() {
File directory=new File(your directory location);//here /home/user/desktop/sound/
final String name=yourFileName; //here a;
String[] myFiles = directory.list(new FilenameFilter() {
public boolean accept(File directory, String fileName) {
if(fileName.lastIndexOf(".")==-1) return false;
if((fileName.substring(0, fileName.lastIndexOf("."))).equals(name))
return true;
else return false;
}
});
if(myFiles.length()>0)
return true;
}
}
When it returns, it will stop the method.
Try this one
FileLocationWithExtension = "nameofFile"+ ".*"
Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted.
How to read all the files in a folder through Java? It doesn't matter which API.
public void listFilesForFolder(final File folder) {
for (final File fileEntry : folder.listFiles()) {
if (fileEntry.isDirectory()) {
listFilesForFolder(fileEntry);
} else {
System.out.println(fileEntry.getName());
}
}
}
final File folder = new File("/home/you/Desktop");
listFilesForFolder(folder);
Files.walk API is available from Java 8.
try (Stream<Path> paths = Files.walk(Paths.get("/home/you/Desktop"))) {
paths
.filter(Files::isRegularFile)
.forEach(System.out::println);
}
The example uses try-with-resources pattern recommended in API guide. It ensures that no matter circumstances the stream will be closed.
File folder = new File("/Users/you/folder/");
File[] listOfFiles = folder.listFiles();
for (File file : listOfFiles) {
if (file.isFile()) {
System.out.println(file.getName());
}
}
In Java 8 you can do this
Files.walk(Paths.get("/path/to/folder"))
.filter(Files::isRegularFile)
.forEach(System.out::println);
which will print all files in a folder while excluding all directories. If you need a list, the following will do:
Files.walk(Paths.get("/path/to/folder"))
.filter(Files::isRegularFile)
.collect(Collectors.toList())
If you want to return List<File> instead of List<Path> just map it:
List<File> filesInFolder = Files.walk(Paths.get("/path/to/folder"))
.filter(Files::isRegularFile)
.map(Path::toFile)
.collect(Collectors.toList());
You also need to make sure to close the stream! Otherwise you might run into an exception telling you that too many files are open. Read here for more information.
All of the answers on this topic that make use of the new Java 8 functions are neglecting to close the stream. The example in the accepted answer should be:
try (Stream<Path> filePathStream=Files.walk(Paths.get("/home/you/Desktop"))) {
filePathStream.forEach(filePath -> {
if (Files.isRegularFile(filePath)) {
System.out.println(filePath);
}
});
}
From the javadoc of the Files.walk method:
The returned stream encapsulates one or more DirectoryStreams. If
timely disposal of file system resources is required, the
try-with-resources construct should be used to ensure that the
stream's close method is invoked after the stream operations are completed.
One remark according to get all files in the directory.
The method Files.walk(path) will return all files by walking the file tree rooted at the given started file.
For instance, there is the next file tree:
\---folder
| file1.txt
| file2.txt
|
\---subfolder
file3.txt
file4.txt
Using the java.nio.file.Files.walk(Path):
Files.walk(Paths.get("folder"))
.filter(Files::isRegularFile)
.forEach(System.out::println);
Gives the following result:
folder\file1.txt
folder\file2.txt
folder\subfolder\file3.txt
folder\subfolder\file4.txt
To get all files only in the current directory use the java.nio.file.Files.list(Path):
Files.list(Paths.get("folder"))
.filter(Files::isRegularFile)
.forEach(System.out::println);
Result:
folder\file1.txt
folder\file2.txt
import java.io.File;
public class ReadFilesFromFolder {
public static File folder = new File("C:/Documents and Settings/My Documents/Downloads");
static String temp = "";
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("Reading files under the folder "+ folder.getAbsolutePath());
listFilesForFolder(folder);
}
public static void listFilesForFolder(final File folder) {
for (final File fileEntry : folder.listFiles()) {
if (fileEntry.isDirectory()) {
// System.out.println("Reading files under the folder "+folder.getAbsolutePath());
listFilesForFolder(fileEntry);
} else {
if (fileEntry.isFile()) {
temp = fileEntry.getName();
if ((temp.substring(temp.lastIndexOf('.') + 1, temp.length()).toLowerCase()).equals("txt"))
System.out.println("File= " + folder.getAbsolutePath()+ "\\" + fileEntry.getName());
}
}
}
}
}
In Java 7 and higher you can use listdir
Path dir = ...;
try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir)) {
for (Path file: stream) {
System.out.println(file.getFileName());
}
} catch (IOException | DirectoryIteratorException x) {
// IOException can never be thrown by the iteration.
// In this snippet, it can only be thrown by newDirectoryStream.
System.err.println(x);
}
You can also create a filter that can then be passed into the newDirectoryStream method above
DirectoryStream.Filter<Path> filter = new DirectoryStream.Filter<Path>() {
public boolean accept(Path file) throws IOException {
try {
return (Files.isRegularFile(path));
} catch (IOException x) {
// Failed to determine if it's a file.
System.err.println(x);
return false;
}
}
};
For other filtering examples, [see documentation].(http://docs.oracle.com/javase/tutorial/essential/io/dirs.html#glob)
private static final String ROOT_FILE_PATH="/";
File f=new File(ROOT_FILE_PATH);
File[] allSubFiles=f.listFiles();
for (File file : allSubFiles) {
if(file.isDirectory())
{
System.out.println(file.getAbsolutePath()+" is directory");
//Steps for directory
}
else
{
System.out.println(file.getAbsolutePath()+" is file");
//steps for files
}
}
Just walk through all Files using Files.walkFileTree (Java 7)
Files.walkFileTree(Paths.get(dir), new SimpleFileVisitor<Path>() {
#Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
System.out.println("file: " + file);
return FileVisitResult.CONTINUE;
}
});
If you want more options, you can use this function which aims to populate an arraylist of files present in a folder. Options are : recursivility and pattern to match.
public static ArrayList<File> listFilesForFolder(final File folder,
final boolean recursivity,
final String patternFileFilter) {
// Inputs
boolean filteredFile = false;
// Ouput
final ArrayList<File> output = new ArrayList<File> ();
// Foreach elements
for (final File fileEntry : folder.listFiles()) {
// If this element is a directory, do it recursivly
if (fileEntry.isDirectory()) {
if (recursivity) {
output.addAll(listFilesForFolder(fileEntry, recursivity, patternFileFilter));
}
}
else {
// If there is no pattern, the file is correct
if (patternFileFilter.length() == 0) {
filteredFile = true;
}
// Otherwise we need to filter by pattern
else {
filteredFile = Pattern.matches(patternFileFilter, fileEntry.getName());
}
// If the file has a name which match with the pattern, then add it to the list
if (filteredFile) {
output.add(fileEntry);
}
}
}
return output;
}
Best, Adrien
File directory = new File("/user/folder");
File[] myarray;
myarray=new File[10];
myarray=directory.listFiles();
for (int j = 0; j < myarray.length; j++)
{
File path=myarray[j];
FileReader fr = new FileReader(path);
BufferedReader br = new BufferedReader(fr);
String s = "";
while (br.ready()) {
s += br.readLine() + "\n";
}
}
nice usage of java.io.FileFilter as seen on https://stackoverflow.com/a/286001/146745
File fl = new File(dir);
File[] files = fl.listFiles(new FileFilter() {
public boolean accept(File file) {
return file.isFile();
}
});
static File mainFolder = new File("Folder");
public static void main(String[] args) {
lf.getFiles(lf.mainFolder);
}
public void getFiles(File f) {
File files[];
if (f.isFile()) {
String name=f.getName();
} else {
files = f.listFiles();
for (int i = 0; i < files.length; i++) {
getFiles(files[i]);
}
}
}
I think this is good way to read all the files in a folder and sub folder's
private static void addfiles (File input,ArrayList<File> files)
{
if(input.isDirectory())
{
ArrayList <File> path = new ArrayList<File>(Arrays.asList(input.listFiles()));
for(int i=0 ; i<path.size();++i)
{
if(path.get(i).isDirectory())
{
addfiles(path.get(i),files);
}
if(path.get(i).isFile())
{
files.add(path.get(i));
}
}
}
if(input.isFile())
{
files.add(input);
}
}
Simple example that works with Java 1.7 to recursively list files in directories specified on the command-line:
import java.io.File;
public class List {
public static void main(String[] args) {
for (String f : args) {
listDir(f);
}
}
private static void listDir(String dir) {
File f = new File(dir);
File[] list = f.listFiles();
if (list == null) {
return;
}
for (File entry : list) {
System.out.println(entry.getName());
if (entry.isDirectory()) {
listDir(entry.getAbsolutePath());
}
}
}
}
While I do agree with Rich, Orian and the rest for using:
final File keysFileFolder = new File(<path>);
File[] fileslist = keysFileFolder.listFiles();
if(fileslist != null)
{
//Do your thing here...
}
for some reason all the examples here uses absolute path (i.e. all the way from root, or, say, drive letter (C:\) for windows..)
I'd like to add that it is possible to use relative path as-well.
So, if you're pwd (current directory/folder) is folder1 and you want to parse folder1/subfolder, you simply write (in the code above instead of ):
final File keysFileFolder = new File("subfolder");
Java 8 Files.walk(..) is good when you are soore it will not throw Avoid Java 8 Files.walk(..) termination cause of ( java.nio.file.AccessDeniedException ) .
Here is a safe solution , not though so elegant as Java 8Files.walk(..) :
int[] count = {0};
try {
Files.walkFileTree(Paths.get(dir.getPath()), new HashSet<FileVisitOption>(Arrays.asList(FileVisitOption.FOLLOW_LINKS)),
Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
#Override
public FileVisitResult visitFile(Path file , BasicFileAttributes attrs) throws IOException {
System.out.printf("Visiting file %s\n", file);
++count[0];
return FileVisitResult.CONTINUE;
}
#Override
public FileVisitResult visitFileFailed(Path file , IOException e) throws IOException {
System.err.printf("Visiting failed for %s\n", file);
return FileVisitResult.SKIP_SUBTREE;
}
#Override
public FileVisitResult preVisitDirectory(Path dir , BasicFileAttributes attrs) throws IOException {
System.out.printf("About to visit directory %s\n", dir);
return FileVisitResult.CONTINUE;
}
});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
void getFiles(){
String dirPath = "E:/folder_name";
File dir = new File(dirPath);
String[] files = dir.list();
if (files.length == 0) {
System.out.println("The directory is empty");
} else {
for (String aFile : files) {
System.out.println(aFile);
}
}
}
package com;
import java.io.File;
/**
*
* #author ?Mukesh
*/
public class ListFiles {
static File mainFolder = new File("D:\\Movies");
public static void main(String[] args)
{
ListFiles lf = new ListFiles();
lf.getFiles(lf.mainFolder);
long fileSize = mainFolder.length();
System.out.println("mainFolder size in bytes is: " + fileSize);
System.out.println("File size in KB is : " + (double)fileSize/1024);
System.out.println("File size in MB is :" + (double)fileSize/(1024*1024));
}
public void getFiles(File f){
File files[];
if(f.isFile())
System.out.println(f.getAbsolutePath());
else{
files = f.listFiles();
for (int i = 0; i < files.length; i++) {
getFiles(files[i]);
}
}
}
}
Just to expand on the accepted answer I store the filenames to an ArrayList (instead of just dumping them to System.out.println) I created a helper class "MyFileUtils" so it could be imported by other projects:
class MyFileUtils {
public static void loadFilesForFolder(final File folder, List<String> fileList){
for (final File fileEntry : folder.listFiles()) {
if (fileEntry.isDirectory()) {
loadFilesForFolder(fileEntry, fileList);
} else {
fileList.add( fileEntry.getParent() + File.separator + fileEntry.getName() );
}
}
}
}
I added the full path to the file name.
You would use it like this:
import MyFileUtils;
List<String> fileList = new ArrayList<String>();
final File folder = new File("/home/you/Desktop");
MyFileUtils.loadFilesForFolder(folder, fileList);
// Dump file list values
for (String fileName : fileList){
System.out.println(fileName);
}
The ArrayList is passed by "value", but the value is used to point to the same ArrayList object living in the JVM Heap. In this way, each recursion call adds filenames to the same ArrayList (we are NOT creating a new ArrayList on each recursive call).
There are many good answers above, here's a different approach: In a maven project, everything you put in the resources folder is copied by default in the target/classes folder. To see what is available at runtime
ClassLoader contextClassLoader =
Thread.currentThread().getContextClassLoader();
URL resource = contextClassLoader.getResource("");
File file = new File(resource.toURI());
File[] files = file.listFiles();
for (File f : files) {
System.out.println(f.getName());
}
Now to get the files from a specific folder, let's say you have a folder called 'res' in your resources folder, just replace:
URL resource = contextClassLoader.getResource("res");
If you want to have access in your com.companyName package then:
contextClassLoader.getResource("com.companyName");
You can put the file path to argument and create a list with all the filepaths and not put it the list manually. Then use a for loop and a reader. Example for txt files:
public static void main(String[] args) throws IOException{
File[] files = new File(args[0].replace("\\", "\\\\")).listFiles(new FilenameFilter() { #Override public boolean accept(File dir, String name) { return name.endsWith(".txt"); } });
ArrayList<String> filedir = new ArrayList<String>();
String FILE_TEST = null;
for (i=0; i<files.length; i++){
filedir.add(files[i].toString());
CSV_FILE_TEST=filedir.get(i)
try(Reader testreader = Files.newBufferedReader(Paths.get(FILE_TEST));
){
//write your stuff
}}}
package com.commandline.folder;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.stream.Stream;
public class FolderReadingDemo {
public static void main(String[] args) {
String str = args[0];
final File folder = new File(str);
// listFilesForFolder(folder);
listFilesForFolder(str);
}
public static void listFilesForFolder(String str) {
try (Stream<Path> paths = Files.walk(Paths.get(str))) {
paths.filter(Files::isRegularFile).forEach(System.out::println);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void listFilesForFolder(final File folder) {
for (final File fileEntry : folder.listFiles()) {
if (fileEntry.isDirectory()) {
listFilesForFolder(fileEntry);
} else {
System.out.println(fileEntry.getName());
}
}
}
}
We can use org.apache.commons.io.FileUtils, use listFiles() mehtod to read all the files in a given folder.
eg:
FileUtils.listFiles(directory, new String[] {"ext1", "ext2"}, true)
This read all the files in the given directory with given extensions, we can pass multiple extensions in the array and read recursively within the folder(true parameter).
public static List<File> files(String dirname) {
if (dirname == null) {
return Collections.emptyList();
}
File dir = new File(dirname);
if (!dir.exists()) {
return Collections.emptyList();
}
if (!dir.isDirectory()) {
return Collections.singletonList(file(dirname));
}
return Arrays.stream(Objects.requireNonNull(dir.listFiles()))
.collect(Collectors.toList());
}
import java.io.File;
import java.util.ArrayList;
import java.util.List;
public class AvoidNullExp {
public static void main(String[] args) {
List<File> fileList =new ArrayList<>();
final File folder = new File("g:/master");
new AvoidNullExp().listFilesForFolder(folder, fileList);
}
public void listFilesForFolder(final File folder,List<File> fileList) {
File[] filesInFolder = folder.listFiles();
if (filesInFolder != null) {
for (final File fileEntry : filesInFolder) {
if (fileEntry.isDirectory()) {
System.out.println("DIR : "+fileEntry.getName());
listFilesForFolder(fileEntry,fileList);
} else {
System.out.println("FILE : "+fileEntry.getName());
fileList.add(fileEntry);
}
}
}
}
}
list down files from Test folder present inside class path
import java.io.File;
import java.io.IOException;
public class Hello {
public static void main(final String[] args) throws IOException {
System.out.println("List down all the files present on the server directory");
File file1 = new File("/prog/FileTest/src/Test");
File[] files = file1.listFiles();
if (null != files) {
for (int fileIntList = 0; fileIntList < files.length; fileIntList++) {
String ss = files[fileIntList].toString();
if (null != ss && ss.length() > 0) {
System.out.println("File: " + (fileIntList + 1) + " :" + ss.substring(ss.lastIndexOf("\\") + 1, ss.length()));
}
}
}
}
}
/**
* Function to read all mp3 files from sdcard and store the details in an
* ArrayList
*/
public ArrayList<HashMap<String, String>> getPlayList()
{
ArrayList<HashMap<String, String>> songsList=new ArrayList<>();
File home = new File(MEDIA_PATH);
if (home.listFiles(new FileExtensionFilter()).length > 0) {
for (File file : home.listFiles(new FileExtensionFilter())) {
HashMap<String, String> song = new HashMap<String, String>();
song.put(
"songTitle",
file.getName().substring(0,
(file.getName().length() - 4)));
song.put("songPath", file.getPath());
// Adding each song to SongList
songsList.add(song);
}
}
// return songs list array
return songsList;
}
/**
* Class to filter files which have a .mp3 extension
* */
class FileExtensionFilter implements FilenameFilter
{
#Override
public boolean accept(File dir, String name) {
return (name.endsWith(".mp3") || name.endsWith(".MP3"));
}
}
You can filter any textfiles or any other extension ..just replace it with .MP3
This will Read Specified file extension files in given path(looks sub folders also)
public static Map<String,List<File>> getFileNames(String
dirName,Map<String,List<File>> filesContainer,final String fileExt){
String dirPath = dirName;
List<File>files = new ArrayList<>();
Map<String,List<File>> completeFiles = filesContainer;
if(completeFiles == null) {
completeFiles = new HashMap<>();
}
File file = new File(dirName);
FileFilter fileFilter = new FileFilter() {
#Override
public boolean accept(File file) {
boolean acceptFile = false;
if(file.isDirectory()) {
acceptFile = true;
}else if (file.getName().toLowerCase().endsWith(fileExt))
{
acceptFile = true;
}
return acceptFile;
}
};
for(File dirfile : file.listFiles(fileFilter)) {
if(dirfile.isFile() &&
dirfile.getName().toLowerCase().endsWith(fileExt)) {
files.add(dirfile);
}else if(dirfile.isDirectory()) {
if(!files.isEmpty()) {
completeFiles.put(dirPath, files);
}
getFileNames(dirfile.getAbsolutePath(),completeFiles,fileExt);
}
}
if(!files.isEmpty()) {
completeFiles.put(dirPath, files);
}
return completeFiles;
}
This will work fine:
private static void addfiles(File inputValVal, ArrayList<File> files)
{
if(inputVal.isDirectory())
{
ArrayList <File> path = new ArrayList<File>(Arrays.asList(inputVal.listFiles()));
for(int i=0; i<path.size(); ++i)
{
if(path.get(i).isDirectory())
{
addfiles(path.get(i),files);
}
if(path.get(i).isFile())
{
files.add(path.get(i));
}
}
/* Optional : if you need to have the counts of all the folders and files you can create 2 global arrays
and store the results of the above 2 if loops inside these arrays */
}
if(inputVal.isFile())
{
files.add(inputVal);
}
}