I have a folder called "all_users" in my java project under the src directory.How can I access the files(if there are any) in the all_users folder. I eventually want to loop through all the existing files in the "all_users" folder, comparing whether the file name is equal to a string i specify in the code.
Firstly, I tried File f = new File(System.getProperty("user.home")+File.pathSeparator + "all_users"); as the file object then later tried File dir = new File(TEST_PATH); Both returned false when i checked if it existed so i didn't set up the path correctly?
public class ValUtility {
static final String TEST_PATH = "./all_users/";
public static boolean validUsername(String user) {
File f = new File(System.getProperty("user.home") + File.pathSeparator + "all_users");
File dir = new File(TEST_PATH);
File[] directoryListing = f.listFiles();
System.out.println(f.exists());
System.out.println(directoryListing);
if (directoryListing != null) {
for (File child : directoryListing) {
// Do something with child
// think child is filename?
if (user.equals(child.getName())){
return false;
}
}
}
return true;
}
}
Please run...
System.out.println(System.getProperty("user.home"));
The above will inform you where you need to add a folder labeled 'all_users'. It is very unlikely that your 'user.home' property is set to your project's source file (src) folder.
As you can see in ss, some apps have created their own folders in my phone root folder.
So that means it's possible, but I couldn't find a way to do this.
Tried this but didn't work,
File folder = new File("/myfolder");
boolean success = true;
if (!folder.exists()) {
success = folder.mkdir();
}
You need to get put the path to sdcard first, like this:
File folder = new File(Environment.getExternalStorageDirectory(), "myfolder");
folder.mkdir();
You don't need to check if folder exists, as mkdir() will just do nothing (and return false) in that case.
Java.IO.File folder = new Java.IO.File(
Android.OS.Environment.ExternalStorageDirectory, "dalisto/cache");
folder.Mkdir ();
I am having an input folder say c:\files\input\ that contains my list of files that I am using.
How do I use the above to create say c:\files\output\ and copy the files from the input folder to the output folder?
My c:\files\input is read from an object, say
String inputFolder = dataMap.getString("folder");// this will get c:\files\input\
You got path of folder in variable inputFolder now do as follows.
String inputFolder = dataMap.getString("folder");
File dir = new File(inputFolder);
if(dir.mkdirs()){
System.out.println("Directory created");
}else{
System.out.println("Directory Not Created");
}
You can use FileUtils from org.apache.commons.io library
FileUtils.copyDirectory(srcDir, destDir);
so in your case:
File file = new File(inputFolder);
String parentDir = file.getParentFile().getAbsolutePath();
File outputDir = new File(parentDir, "output");
if(!outputDir.exsit()) {
outputDir.mkdir();
}
FileUtils.copyDirectory(inputFolder, outputDir);
To Create the directory you can refer to the below code
File file = new File("c:\\files\\output");
if (!file.exists()) {
if (file.mkdir()) {
System.out.println("Directory is created!");
} else {
System.out.println("Failed to create directory!");
}
}
To copy files from a directory to another directory.. refer to the following link it gives a good explanation with source code examples
http://examples.javacodegeeks.com/core-java/io/file/4-ways-to-copy-file-in-java/
I am trying to move a file from one directory to another using renameTo() in java, however renameTo doesnt work (doesnt rename and move the file). Basically, I want to delete the file in one first with same file name, then copy a file from anoter directory to the same location where I deleted the file originally, then copy the new one with same name.
//filePath = location of original file with file name appended. ex: C:\Dir\file.txt
//tempPath = Location of file that I want to replace it to file file without the file name. ex: C:\AnotherDir
int pos = filePath.indexOf("C:\\Dir\\file.txt");
//Parse out only the path, so just C:\\Dir
String newFilePath = filePath.substring(0,pos-1);
//I want to delete the original file
File deletefile = new File(newFilePath,"file.txt");
if (deletefile.exists()) {
success = deletefile.delete();
}
//There is file already exists in the directory, but I am just appending .tmp at the end
File newFile = new File(tempPath + "file.txt" + ".tmp");
//Create original file again with same name.
File oldFile = new File(newFilePath, "file.txt");
success = oldFile.renameTo(newFile); // This doesnt work.
Can you tell me what I am doing wrong?
Thanks for your help.
You need to escape the backslashes in the string literal: "C:\\Dir\\file.txt". Or use File.separator to construct the path.
Additionally, ensure newFile's path is constructed properly:
File newFile = new File(tempPath + File.separator + "file.txt" + ".tmp");
//^^^^^^^^^^^^^^^^
as the commments in the posted code (...ex: C:\AnotherDir) indicate that tempPath has no trailing slash character.
I have moved files to the destination directory and after moving deleted those moved files from source folder, in three ways, and at last am using the 3rd approach in my project.
1st approach:
File folder = new File("SourceDirectory_Path");
File[] listOfFiles = folder.listFiles();
for (int i = 0; i < listOfFiles.length; i++) {
Files.move(Paths.get("SourceDirectory_Path"+listOfFiles[i].getName()), Paths.get("DestinationDerectory_Path"+listOfFiles[i].getName()));
}
System.out.println("SUCCESS");
2nd approach:
Path sourceDir = Paths.get("SourceDirectory_Path");
Path destinationDir = Paths.get("DestinationDerectory_Path");
try(DirectoryStream<Path> directoryStream = Files.newDirectoryStream(sourceDir)){
for (Path path : directoryStream) {
File d1 = sourceDir.resolve(path.getFileName()).toFile();
File d2 = destinationDir.resolve(path.getFileName()).toFile();
File oldFile = path.toFile();
if(oldFile.renameTo(d2)){
System.out.println("Moved");
}else{
System.out.println("Not Moved");
}
}
}catch (Exception e) {
e.printStackTrace();
}
3rd approach:
Path sourceDirectory= Paths.get(SOURCE_FILE_PATH);
Path destinationDirectory = Paths.get(SOURCE_FILE_MOVE_PATH);
try (DirectoryStream<Path> directoryStream = Files.newDirectoryStream(sourceDirectory)) {
for (Path path : directoryStream) {
Path dpath = destinationDirectory .resolve(path.getFileName());
Files.move(path, dpath, StandardCopyOption.REPLACE_EXISTING);
}
} catch (IOException ex) {
ex.printStackTrace();
}
Happy Coding !! :)
How do I create Directory/folder?
Once I have tested System.getProperty("user.home");
I have to create a directory (directory name "new folder" ) if and only if new folder does not exist.
new File("/path/directory").mkdirs();
Here "directory" is the name of the directory you want to create/exist.
After ~7 year, I will update it to better approach which is suggested by Bozho.
File theDir = new File("/path/directory");
if (!theDir.exists()){
theDir.mkdirs();
}
With Java 7, you can use Files.createDirectories().
For instance:
Files.createDirectories(Paths.get("/path/to/directory"));
You can try FileUtils#forceMkdir
FileUtils.forceMkdir("/path/directory");
This library have a lot of useful functions.
mkdir vs mkdirs
If you want to create a single directory use mkdir
new File("/path/directory").mkdir();
If you want to create a hierarchy of folder structure use mkdirs
new File("/path/directory").mkdirs();
Create a single directory.
new File("C:\\Directory1").mkdir();
Create a directory named “Directory2 and all its sub-directories “Sub2″ and “Sub-Sub2″ together.
new File("C:\\Directory2\\Sub2\\Sub-Sub2").mkdirs()
Source: this perfect tutorial , you find also an example of use.
For java 7 and up:
Path path = Paths.get("/your/path/string");
Files.createDirectories(path);
It seems unnecessary to check for existence of the dir or file before creating, from createDirectories javadocs:
Creates a directory by creating all nonexistent parent directories first. Unlike the createDirectory method, an exception is not thrown if the directory could not be created because it already exists.
The attrs parameter is optional file-attributes to set atomically when creating the nonexistent directories. Each file attribute is identified by its name. If more than one attribute of the same name is included in the array then all but the last occurrence is ignored.
If this method fails, then it may do so after creating some, but not all, of the parent directories.
The following method should do what you want, just make sure you are checking the return value of mkdir() / mkdirs()
private void createUserDir(final String dirName) throws IOException {
final File homeDir = new File(System.getProperty("user.home"));
final File dir = new File(homeDir, dirName);
if (!dir.exists() && !dir.mkdirs()) {
throw new IOException("Unable to create " + dir.getAbsolutePath();
}
}
Neat and clean:
import java.io.File;
public class RevCreateDirectory {
public void revCreateDirectory() {
//To create single directory/folder
File file = new File("D:\\Directory1");
if (!file.exists()) {
if (file.mkdir()) {
System.out.println("Directory is created!");
} else {
System.out.println("Failed to create directory!");
}
}
//To create multiple directories/folders
File files = new File("D:\\Directory2\\Sub2\\Sub-Sub2");
if (!files.exists()) {
if (files.mkdirs()) {
System.out.println("Multiple directories are created!");
} else {
System.out.println("Failed to create multiple directories!");
}
}
}
}
Though this question has been answered. I would like to put something extra, i.e.
if there is a file exist with the directory name that you are trying to create than it should prompt an error. For future visitors.
public static void makeDir()
{
File directory = new File(" dirname ");
if (directory.exists() && directory.isFile())
{
System.out.println("The dir with name could not be" +
" created as it is a normal file");
}
else
{
try
{
if (!directory.exists())
{
directory.mkdir();
}
String username = System.getProperty("user.name");
String filename = " path/" + username + ".txt"; //extension if you need one
}
catch (IOException e)
{
System.out.println("prompt for error");
}
}
}
Just wanted to point out to everyone calling File.mkdir() or File.mkdirs() to be careful the File object is a directory and not a file. For example if you call mkdirs() for the path /dir1/dir2/file.txt, it will create a folder with the name file.txt which is probably not what you wanted. If you are creating a new file and also want to automatically create parent folders you can do something like this:
File file = new File(filePath);
if (file.getParentFile() != null) {
file.getParentFile().mkdirs();
}
This the way work for me do one single directory or more or them:
need to import java.io.File;
/*enter the code below to add a diectory dir1 or check if exist dir1, if does not, so create it and same with dir2 and dir3 */
File filed = new File("C:\\dir1");
if(!filed.exists()){ if(filed.mkdir()){ System.out.println("directory is created"); }} else{ System.out.println("directory exist"); }
File filel = new File("C:\\dir1\\dir2");
if(!filel.exists()){ if(filel.mkdir()){ System.out.println("directory is created"); }} else{ System.out.println("directory exist"); }
File filet = new File("C:\\dir1\\dir2\\dir3");
if(!filet.exists()){ if(filet.mkdir()){ System.out.println("directory is created"); }} else{ System.out.println("directory exist"); }
if you want to be sure its created then this:
final String path = "target/logs/";
final File logsDir = new File(path);
final boolean logsDirCreated = logsDir.mkdir();
if (!logsDirCreated) {
final boolean logsDirExists = logsDir.exists();
assertThat(logsDirExists).isTrue();
}
beacuse mkDir() returns a boolean, and findbugs will cry for it if you dont use the variable. Also its not nice...
mkDir() returns only true if mkDir() creates it.
If the dir exists, it returns false, so to verify the dir you created, only call exists() if mkDir() return false.
assertThat() will checks the result and fails if exists() returns false. ofc you can use other things to handle the uncreated directory.
This function allows you to create a directory on the user home directory.
private static void createDirectory(final String directoryName) {
final File homeDirectory = new File(System.getProperty("user.home"));
final File newDirectory = new File(homeDirectory, directoryName);
if(!newDirectory.exists()) {
boolean result = newDirectory.mkdir();
if(result) {
System.out.println("The directory is created !");
}
} else {
System.out.println("The directory already exist");
}
}
Here is one attractiveness of the java, using Short Circuit OR '||', testing of the directory's existence along with making the directory for you
public File checkAndMakeTheDirectory() {
File theDirectory = new File("/path/directory");
if (theDirectory.exists() || theDirectory.mkdirs())
System.out.println("The folder has been created or has been already there");
return theDirectory;
}
if the first part of the if is true it does not run the second part and if the first part is false it runs the second part as well
public class Test1 {
public static void main(String[] args)
{
String path = System.getProperty("user.home");
File dir=new File(path+"/new folder");
if(dir.exists()){
System.out.println("A folder with name 'new folder' is already exist in the path "+path);
}else{
dir.mkdir();
}
}
}