Develop Reference

Creating Directories and Sub directories and getting files inside sub directories [duplicate]

I want to write a new file with the FileWriter. I use it like this:
FileWriter newJsp = new FileWriter("C:\\user\Desktop\dir1\dir2\filename.txt");
Now dir1 and dir2 currently don't exist. I want Java to create them automatically if they aren't already there. Actually Java should set up the whole file path if not already existing.
How can I achieve this?

Something like:
File file = new File("C:\\user\\Desktop\\dir1\\dir2\\filename.txt");
file.getParentFile().mkdirs();
FileWriter writer = new FileWriter(file);

Since Java 1.7 you can use Files.createFile:
Path pathToFile = Paths.get("/home/joe/foo/bar/myFile.txt");
Files.createDirectories(pathToFile.getParent());
Files.createFile(pathToFile);

Use File.mkdirs():
File dir = new File("C:\\user\\Desktop\\dir1\\dir2");
dir.mkdirs();
File file = new File(dir, "filename.txt");
FileWriter newJsp = new FileWriter(file);

Use File.mkdirs().

Use FileUtils to handle all these headaches.
Edit: For example, use below code to write to a file, this method will 'checking and creating the parent directory if it does not exist'.
openOutputStream(File file [, boolean append])

Java make directory but not file

So with the code below it creates the file in the folder
File f = new File(path);
if(!f.exists())
f.mkdirs();
, but i only want to create the directory, because after this i use this code
file.transferTo(new File(path));
which saves a Multipart file to the same location, but it throws and error because there is already a file. Is there a way only to create the folder without the file ? One solution is to delete the first file, but looking for better solution
EDIT:
File f = new File(path);
this line creates the folders and the file, it shouldn't. I use java 8 and IntelliJ 14
SOLUTION:
The problem was Intellij or Intellij debug watches. After restarting it and clearing watches which were like:
new File(path)
file.transferTo(new File(path))
f.exists()
The code started working.

It should be
f.getParentFile().mkdirs();
You don't need to check for existence beforehand: mkdirs() already does that.

File dir = new File("<Your_Path>/TestDirectory");
// attempt to create the directory here
boolean successful = dir.mkdir();
if (successful)
{
// creating the directory succeeded
System.out.println("directory was created successfully");
}
else
{
// creating the directory failed
System.out.println("failed trying to create the directory");
}
You can create your files inside your directory path from then on....

Selecting txt file from any location with File Chooser in Java

I have used the Sun File Chooser Demo to choose files from my desktop or any location.
I have added the following code in the open file action:
if (returnVal == JFileChooser.APPROVE_OPTION) {
File file = fc.getSelectedFile();
log.append("Opening: " + file.getName() + "." + newline);
ReadData rd = new ReadData(); //added by me
rd.readData(file.getName()); //added by me
} else {
log.append("Open command cancelled by user." + newline);
ReadData class contains readData method which will take the file name and with BufferedReader will read the contents of the file line by line.
But after choosing the file with file chooser it is not able to open the file from my desktop.If I place the file inside the project folder it is able to open the file without any code change.
What modification in code I need to do so that it can choose and open file from any location?
Thanks

You are passing only the file's name, not the complete path, to your ReadData class. So, your ReadData class is not going to know in which directory the file is - it will try to find it in the current directory (whatever that is at the moment).
Instead of just passing the name of the file, pass the whole path:
rd.readData(file.getPath());
Better yet, change your ReadData.readData() method so that it takes a File instead of a String, and pass it the File object that you get back from the file chooser:
rd.readData(file);

getName() only gets the last segment of the file without any path information. If the working directory of your Java application isn't the exact directory that holds that file, that won't work.
Why doesn't your ReadData just take a file? All file input mechanisms built into Java will accept a File (e.g. FileInputStream, FileReader). Otherwise use getPath() I guess.

You are only passing the name of the file to the readData() method.
So if your file is stored at C:\Users\JavaBits\Project\Java\file.txt, your readData() method is only getting file.txt so it can't find the file. You should do this:
rd.readData(file);
This will have the relative path in it.

use file object to open inputstream instead using its name. such as:
BufferedReader br = new BufferedReader(new FileInputStream(file));
modify your method readData to accept File object instead String, and use this object to open BufferedReader.

Problem with moving a file to another folder

I am using:
// File (or directory) to be moved
File file = new File(output.toString());
// Destination directory
File dir = new File(directory_name);
// Move file to new directory
boolean success = file.renameTo(new File(dir, new_file.getName()));
if (!success) {
// File was not successfully moved
}
In this case file is main.vm, and folder is seven
the program shows that it works(the file exists and all) but the file is not moving to the seven directory.
Any ideas why?
Is it ok that the file name is main.vm or do i need to enter full path? the same for the folder.
Thanks

Maybe you wanna take a look at the Apache Commons FileUtils

Works for me. (run with java -ea opt.)
File f = new File("foo.mv");
if(!f.exists())
assert f.createNewFile() : "failed to create foo.mv";
File folder = new File("7");
if(!folder.exists())
assert folder.mkdir() : "failed to create new directory";
File fnew = new File(folder, f.getName());
assert !fnew.exists() : "fnew already exists";
f.renameTo(fnew);
assert fnew.exists() : "fnew does not exist -- move failed";
System.out.format("moved %s to %s\n",f, fnew);

Try to do following steps:
check if you move the file inside same filesystem - otherwise it will fail;
create destination directory;
define "new_file" variable.

You need to enter full path of the file, not only the filename. And would be nice if you'll show up your full source code in the future, for better understanding/answers.

Android writing to a CSV file via OpenCsv

I try to write to a Csv file via:
mFileWriter = new FileWriter(
"/sdcard/program/file");
mCsvWriter = new CSVWriter(mFileWriter);
At the moment it throws an exception that the file doesn't exist.
It's true that the file doesn't exist. What's the easiest way to create the file?

Does the FILE not exist, or the DIRECTORY it's supposed to go into?
If you want to create a directory structure, you can always do
File file = new File("/full/path/to/file");
file.mkdirs();
This will create any path leading up to this file that doesn't exist yet.
I suppose the missing quotes around your file name are a typo?