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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);
}
}
I managed to find two example snippets of code for zipping a directory with Java:
public static void pack(final Path folder, final Path zipFilePath) throws IOException {
try (
FileOutputStream fos = new FileOutputStream(zipFilePath.toFile());
ZipOutputStream zos = new ZipOutputStream(fos)
) {
Files.walkFileTree(folder, new SimpleFileVisitor<Path>() {
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
zos.putNextEntry(new ZipEntry(folder.relativize(file).toString()));
Files.copy(file, zos);
zos.closeEntry();
return FileVisitResult.CONTINUE;
}
public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
zos.putNextEntry(new ZipEntry(folder.relativize(dir).toString() + "/"));
zos.closeEntry();
return FileVisitResult.CONTINUE;
}
});
}
}
and
public static void pack(String sourceDirPath, String zipFilePath) throws IOException {
Path p = Files.createFile(Paths.get(zipFilePath));
try (ZipOutputStream zs = new ZipOutputStream(Files.newOutputStream(p))) {
Path pp = Paths.get(sourceDirPath);
Files.walk(pp)
.filter(path -> !Files.isDirectory(path))
.forEach(path -> {
ZipEntry zipEntry = new ZipEntry(pp.relativize(path).toString());
try {
zs.putNextEntry(zipEntry);
zs.write(Files.readAllBytes(path));
zs.closeEntry();
} catch (Exception e) {
System.err.println(e);
}
});
}
}
But, for both examples, I can't for the life of me figure out how to exclude certain sub-directories within the source directories from being included in the output zip.
Could somebody lend me a hand?
Thank you so much!
The short answer is to define your directory filter in the preVisitDirectory(...) method such that it returns FileVisitResult.SKIP_SUBTREE whenever it pre-visits a directory that you would like to exclude.
For more details, see the Controlling the Flow section of Walking the File Tree.
Edit:
As requested, a sample implementation using the above provided code. Create an instance of it with paths to the source directory (srcPath) and Zip file name (zipPath). Add any directory names to be excluded. For example, addDirExclude( "bin" ) would exclude any directory named bin, its files, and any sub-directories thereunder.
This is an example, intended to demonstration one of several ways to further control a file tree walk. This is not production quality code; use at your own risk.
public class ZipWithExcludedDirs {
final private Path srcPath;
final private Path zipPath;
final private List<String> excludeList = new ArrayList<>();
public ZipWithExcludedDirs( Path srcPath, Path zipPath ) {
this.srcPath = srcPath;
this.zipPath = zipPath;
}
public void addDirExclude( String exDir ) {
excludeList.add( exDir );
}
public void pack() throws IOException {
try ( FileOutputStream fos = new FileOutputStream( zipPath.toFile() );
ZipOutputStream zos = new ZipOutputStream( fos ) ) {
Files.walkFileTree( srcPath, new SimpleFileVisitor<Path>() {
public FileVisitResult visitFile( Path file, BasicFileAttributes attrs )
throws IOException {
zos.putNextEntry( new ZipEntry( file.toString() ) );
Files.copy( file, zos );
zos.closeEntry();
return FileVisitResult.CONTINUE;
}
public FileVisitResult preVisitDirectory( Path dir, BasicFileAttributes attrs )
throws IOException {
String dirName = dir.getFileName().toString();
for ( String excl : excludeList )
if ( dirName.equals( excl ) )
return FileVisitResult.SKIP_SUBTREE;
zos.putNextEntry( new ZipEntry( dir.toString() + "/" ) );
zos.closeEntry();
return FileVisitResult.CONTINUE;
}
} );
}
}
}
Edit (Part Deux)
I have edited the above code such that it returns SKIP_SUBTREE instead of SKIP_SIBLINGS, which is what I had originally, but changed for some reason. A glance at the JavaDocs appears to indicate that SKIP_SUBTREE and SKIP_SIBLINGS have the same effect on the directory being visited. It does. However SKIP_SIBLINGS also affects siblings of the directory (i.e. files and directories that follow it in the same parent directory).
Furthermore, the original file walker code referenced by OP, causes an erroneous artifact to be included. This was due to the "relativizing" of the ZipEntry path. Paths should not adjusted in SimpleFileVistor. If there is a need for an archive to be relative or
absolute, then the original srcPath should set as such.
I need to get all the absolute file path of the files with extension .pdf. I am using the code mentioned below, but I'm able to only get the absolute file path of only one file.
How can I modify the code to get all the absolute file paths ?
public class FindFiles {
String absoluteFilePath = "";
String fileName;
public String PdfFiles(String parentDirectory, String fileExtension) {
FileFilter fileFilter = new FileFilter(fileExtension);
File parentDir = new File(parentDirectory);
// Put the names of all files ending with .pdf in a String array
String[] listOfTextFiles = parentDir.list(fileFilter);
if (listOfTextFiles.length == 0) {
System.out.println("There are no files in this direcotry!");
}
for (String file : listOfTextFiles) {
//construct the absolute file paths...
absoluteFilePath = new StringBuffer(parentDirectory).append(File.separator).append(file).toString();
fileName = file.toString();
}
return absoluteFilePath;
}
public static void main(String args[]) {
FindFiles f = new FindFiles();
f.PdfFiles("", "");
}
}
you are overrding absoluteFilePath every time in the loop;
try with
absoluteFilePath += new StringBuffer(parentDirectory).append(File.separator).append(file).toString();
Don't be bothered, use java.nio.file:
final Path dir = Paths.get(baseDir).toAbsolutePath();
final String filter = "*." + extension;
final List<Path> ret = new ArrayList<>();
try (
final DirectoryStream<Path> dirstream
= Files.newDirectoryStream(dir, filter);
) {
for (final Path entry: dirstream)
ret.add(entry);
}
return ret;
If you use Java 8, it's even more simple.
A more efficient solution for your problem can be given using classes in java.nio package.
E.g. For checking whether a file is a pdf file or not, use Files.probeContentType(Path path).
Instead of writing loops to visit all directories and files inside these directories, use Files.walkFileTree(Path start, FileVisitor<? super Path> visitor)
Solution for your problem using these classes are
public class FindPdfFiles {
public static void main(String[] args) throws IOException{
final Path path = Paths.get("C:\\SearchDirectoryForPDF");
Files.walkFileTree(path, new FindPdfFilesFilter());
}
}
class FindPdfFilesFilter extends SimpleFileVisitor<Path> {
#Override
public FileVisitResult visitFile(Path path, BasicFileAttributes arg1)
throws IOException {
final String mimeTypeOfFile = Files.probeContentType(path);
if(mimeTypeOfFile != null && !mimeTypeOfFile.isEmpty() && mimeTypeOfFile.toLowerCase().contains("pdf")) {
System.out.println(path.toString());
}
return FileVisitResult.CONTINUE;
}
}
I have a folder with 3 picture inside of them which I wish to zip and email. I have a method that does this which I've used with previous problems and it works fine. However this time it keeps generating an invalid zip and when I open the zip it only has 1 picture inside with a size of 0.
I can't seems to figure out why though. This is the method:
//generate the zip file for the picture
String zipFile = context.getExternalFilesDir(null) + "/ArcFlash/Checklist.zip";
String srcDir = context.getExternalFilesDir(null) + "/ArcFlash/CheckListMedia";
FileOutputStream fos = new FileOutputStream(zipFile);
ZipOutputStream zos = new ZipOutputStream(fos);
File srcFile = new File(srcDir);
addDirToArchive(zos, srcFile, context);
here is my addDirToArchive method which generates the zip:
private static void addDirToArchive(ZipOutputStream zos, File srcFile, Context ctx)
{
File[] files = srcFile.listFiles();
for (int i = 0; i < files.length; i++)
{
// if the file is directory, use recursion
if (files[i].isDirectory())
{
addDirToArchive(zos, files[i], ctx);
continue;
}
try
{
System.out.println("tAdding file: " + files[i].getName());
// create byte buffer
byte[] buffer = new byte[1024];//2048
FileInputStream fis = new FileInputStream(files[i]);
String target = ctx.getExternalFilesDir(null) + "/";
String oldPath = files[i].getPath();
String newPath = oldPath.replace(target, "");
zos.putNextEntry(new ZipEntry(newPath));
int length;
while ((length = fis.read(buffer)) > 0)
{
zos.write(buffer, 0, length);
}
zos.closeEntry();
// close the InputStream
fis.close();
}
catch (Exception ex)
{
Log.i("customException", "error zipping: " + ex.getMessage());
}
}
}
EDIT
Using the code samples below, here is how to do what you want:
final Path basePath = Paths.get(context.getExternalFilesDir(null));
final Path srcDir = Paths.resolve("ArcFlash/CheckListMedia");
final Path zipFile = Paths.resolve("ArcFlash/Checklist.zip");
final Map<String, Object> env = new HashMap<>();
env.put("create", "true");
final URI zip = URI.create("jar:file:" + zipFile.toAbsolutePath().toString());
try (
final FileSystem fs = FileSystems.newFileSystem(zip, env, null);
) {
Files.walkFileTree(srcDir, new CopyFileVisitor(srcDir, fs.getPath("/")));
}
First, a sample of how to create a zip file:
public final class ZipZip
{
public static void main(final String... args)
throws IOException
{
final Map<String, Object> env = new HashMap<>();
env.put("create", "true");
final URI zip = URI.create("jar:file:/tmp/t.zip");
final Path sourceFile = Paths.get("/tmp/foo.txt");
Files.deleteIfExists(Paths.get("/tmp/t.zip"));
try (
final FileSystem fs = FileSystems.newFileSystem(zip, env, null);
) {
final Path zipdir = fs.getPath("/dir");
Files.createDirectory(zipdir);
final Path zipfile = zipdir.resolve("t.txt");
Files.copy(sourceFile, zipfile);
}
}
}
Then, I have recently written a FileVisitor to recursively copy a directory, which is used here; here is its code:
public final class CopyFileVisitor
implements FileVisitor<Path>
{
private final Path srcdir;
private final Path dstdir;
public CopyFileVisitor(final Path srcdir, final Path dstdir)
{
this.srcdir = srcdir.toAbsolutePath();
this.dstdir = dstdir.toAbsolutePath();
}
#Override
public FileVisitResult preVisitDirectory(final Path dir,
final BasicFileAttributes attrs)
throws IOException
{
Files.createDirectories(toDestination(dir));
return FileVisitResult.CONTINUE;
}
#Override
public FileVisitResult visitFile(final Path file,
final BasicFileAttributes attrs)
throws IOException
{
System.out.printf("%s -> %s\n", file.toAbsolutePath(),
toDestination(file));
Files.copy(file, toDestination(file));
return FileVisitResult.CONTINUE;
}
#Override
public FileVisitResult visitFileFailed(Path file, IOException exc)
throws IOException
{
throw exc;
}
#Override
public FileVisitResult postVisitDirectory(Path dir, IOException exc)
throws IOException
{
if (exc != null)
throw exc;
return FileVisitResult.CONTINUE;
}
private Path toDestination(final Path victim)
{
final Path tmp = victim.toAbsolutePath();
final Path rel = srcdir.relativize(tmp);
return dstdir.resolve(rel.toString());
}
}
I strongly recommend you to use this library for zipping/unzipping contents:
http://www.lingala.net/zip4j/
Be sure you are adding correct headers while making the file.