Could anyone please tell me how to make a symbolic link (in the same way MKLINK does) and/or remove a symbolic link with Java. I have found solutions that use Java as a wrapper and use a Windows native program to accomplish this, but I really want a pure Java solution. Thank you in advance!
Since Java 7 you can do this easily using the NIO package.
Path target = Paths.get("target");
Path link = Paths.get("link");
Files.createDirectory(target);
Files.createSymbolicLink(link, target);
Do remember that you do need the correct privileges for this. In my unit test I had to run eclipse as an administrator to make it work (same as that I couldn't create a link from a normal cmd.exe)
As far as I know window does not have real symbolic links like Unix-like system do.
However Windows has the following relevant tools:
You can map network drive, i.e. attach drive letter to specified network path. You can definitely do this using WMI. To access WMI from java take a look on tools like JaWin, Jinterop, Jintegra or write WMI script in JScript o VBScript and execute is from Java.
You can use command subst that assigns letter to local file system path. This is the closest approach to Unix soft link.
You can create desktop shortcut. Create one manually and take a look on it. Shortcut is actually regular text file (as far as I remember in INI format). You can easily create one using any language you want including java. This is not soft link but it is clickable.
Related
In Linux, I'll usually put user configuration files in $HOME/.myapp and in Windows I'll use APPDATA. So far so good.
What about non-user specific configuration? In linux, I'd put it into /etc. Is there an equivalent in Windows? Please note I would like to have the service running before any user logs in. Also, in case it plays a role, I'm developing in Java.
Alternatively: I approaching this the wrong way?
You could use ALLUSERPROFILES as a base directory. This environment variable resolves to the C:\PROGRAMDATA folder in Windows7. Of course you need to add a specific folder for your applications
In summary, you should use the known folder: ProgramData.
To avoid hard coding of paths (and hence why I'm not providing them here) you should always retrieve the value via one of the following methods:
The %PROGRAMDATA% environment variable (you can also use %ALLUSERSPROFILE% but I consider %PROGRAMDATA% more meaningful)
For unmanaged code use SHGetKnownFolderPath, passing the FOLDERID_ProgramData.
For managed code use System.Environment.GetFolderPath, passing CommonApplicationData.
This folder is not writeable by non-admins, so depending on your requirements you'll want to create a directory for your program and set the ACLs you need at install time.
Some good information on this topic is provided in the blog post: "Where Should I Write Program Data Instead of Program Files".
For those interested in using other Known Folders, MSDN provides extensive documentation.
In Windows most "program files" for an app go in C:\Program Files\MyApp. The environment variable would be %ProgramFiles%\MyApp.
I have a program, written in Java, which originally used its directory in Program Files to write files accessible to all users of this program. This required our users to run as administrator all the time. In an effort to alleviate that, we decided to move files which needed to be written during regular usage to the ProgramData folder using the %ALLUSERSPROFILE% environment variable. Using a subfolder in this directory for our application works great if it is designated as writable during the installation process, which works fine using NSIS.
The problem comes with upgrading existing users. The Java File API provides setWritable but this does not appear to work after testing on development machines. It looks as though the new file API with Java 7 would solve this problem, but with no release date on the horizon I would rather not wait.
It seems the simplest solution would be to use JNA to call the appropriate Windows API call to set this directory writable. Since upgrading the software necessitates admin rights, similar to installing, it should let this change go through fine. However, I'm unsure where to start, having never used JNA before or the Windows API. Suggestions as to which Windows library to load and what functions to call would be appreciated, especially if someone has encountered a similar problem before.
Well, I'm glad you gave some background...You could use JNA, but the easier way would be to execute a call to the command-line utility cacls. It's included by default in Windows XP installations, I believe, so it should do the trick for you. Try Runtime.getRuntime().exec("C:\\Windows\\System32\\cacls.exe"+options)
Check out the documentation here -> http://technet.microsoft.com/en-us/library/bb490872.aspx
I use the follow line:
Runtime.getRuntime().exec( "C:\\Windows\\System32\\icacls.exe \"%ProgramData%\my application" /grant *S-1-5-32-545:(OI)(CI)(W,M)" );
S-1-5-32-545 is the SID for BUILTIN\Users because the name work only on English systems. https://support.microsoft.com/de-de/kb/163846
This give the BUILTIN\Users write access to all files in the given directory independent which user has create it.
Hey i am hoping to write a program where the program automatically just copy pastes all my dad's documents from D:\office folder. So whenever I plug-in my pen-drive , the program silently copies all documents inside my pen-drive. Also all files should be pasted to a hidden folder in the pen-drive (so it remains private) . Synchronization capability also required ...So which language should be easy and where to get started ...any idea ??.
Seems to me that some spyin' is about to be goin' on here. :P
I'd recommend C++. Not extremely easy as .Net's tillyvally but fast, framework independent, convenient to manipulate Windows API. You wanna do advanced stealth app, you can't pick the easy way.
Why use the clipboard when you could just use shell commands???
Maybe write an autostart batch file on your pen drive that copies files to/from your flash drive as needed.
I infer you are on Windows. Window has a plethora of functions to manipulate files. A few functions are below.
CopyFile Copies an existing file to a new file.
FindFirstFile Searches a directory for a file or subdirectory name that matches a specified name.
FindFirstFileEx Searches a directory for a file or subdirectory name and attributes that match those that are specified.
FindNextFile Continues a file search.
MoveFile Moves an existing file or directory and its children.
On and on. These and many more functions are documented here.
File Management Functions
Copy or move the files to the pen drive.
HTH
I hate to be the person who suggests this (I don't like .NET that much):
Make a C# (or VB if you must) Console app, or Forms app (if you want to get fancy). The .NET framework will make this kind of program VERY easy and it might be fun. Unless you want to increase your proficiency in C/C++, i would suggest NOT doing it in those languages since there is a learning curve and it is a little complex to do some simple things.
"Just paste" or "synchronize"?
For synchronization, unison is a good bet, see http://en.wikipedia.org/wiki/Unison_(file_synchronizer). For "just paste", you could code a call to a batch calling XCOPY from with the Windows Autoplay mechanism.
Sounds like a secret covert operation you're talking about, though...
I think that you will need to do a lot of work to get a less than satisfactory result.
I would suggestion you instead have a look at DropBox, which is free up to 2Gb of storage which automatically synchronizes between all registered computers, plus has a special folder which allows for web access. Very nice.
I would suggest to use Camel framework of Java, there you can easily run service which will for example automatically copy data from your flash disk after plug in, to folder which you specify etc.
Good tutorial how to start is here:
https://www.youtube.com/watch?v=dmtXkA7FlwA
This Java code lists files in a directory on a Windows shared drive. Will it work correctly on a Unix system?
File directory = new File("\\\\server/Shared/stuff/mystuff");
for (File file: directory.listFiles()) {
System.out.println(file);
}
Short answer: No.
Long answer: Do you have samba installed? Even then you need to mount the the share. So it probably won't work.
EDIT
Java delegates the call to the underlying OS eventually. Since Unix doesn't know what the \\SERVERNAME path means, Java doesn't know what it means either. What you have to do, to get this to work is mount the drive explicitly using Samba. Your other option, if you are running Ubuntu, is look under .gvfs in your home directory. Ubuntu creates a mount there for your Samba shares, which you should be able to access using Java. If you don't want to rely on external tools, try JCIFS for a pure-Java solution.
No...
Just let the user select the right path and use an OS dependent file-selection dialog.
On my system (Debian Sid with Gnome 2.30 Desktop) I have to select "smb:///server/Shared/..." to achieve the same behaviour. I think, that GVFS (Gnome Virtual File System) using smbfs drivers handles the real connection in the background...
No, as that is a UNC Path, which is a windowsism.
Are you trying to access a windows share from unix? Then have a look at jcifs.
The counter question I get when seeing this is: "Why would you want to hard-code a path in your application?"
Even if it was just for the example and you intend to load the path from a property file or anything, I still think you are on the wrong track here.
First of all you will want to avoid absolute paths like the plague. Relative paths are sort of ok. You can use slash ('/') characters in paths hardcoded, it will work on both Windows and Linux/Mac. Basically all platforms.
Second of all, why use paths at all? This is the internet age. Use URL's! file: URL's will accomplish the same thing as file paths, but using URL's make your app accept resources from other sources such as web sites and FTP as well.
Third of all, avoid the File class. If you invent a good way to do that, you are out of the woodworks completely. Use URL's together with getResource and getResourceAsStream and your app will work platform independent and across network boundaries over the internet.
Specifically getting on Windows the "..\Documents & Settings\All Users, basicaly any path that needs the front end to be dynamically derived based on the OS your software is running on. (Now I need the answer to this)
the current users My Documents dirctory (okay this has been answered)
and basicaly any path that needs the front end to be dynamically derived based on the OS your software is running on.
My docs would probably best be handled by accessing:
System.getProperty("user.home");
Look up the docs on System.getProperty.
Any information you can get about the user's environment can be fetched from
System.getProperty("...");
For a list of what you can get, take a look here.
I don't think you'll be able to get the path you require (the All Users path) in an OS dependent way. After all - do other operating systems have an equivalent? Your best bet is to probably inspect:
System.getProperty("os.name");
to see if you are running Windows and then if so use "C:\Documents & Settings\All Users\".
But you'll be better off just constantly using
System.getProperty("user.home");
(as mentioned by other people) throughout the application. Or alternatively, allow the user to specify the directory to store whatever it is you want to store.
Specifically getting on Windows the "..\Documents & Settings\All Users, basicaly any path that needs the front end to be dynamically derived based on the OS your software is running on. (Now I need the answer to this)
The folders below the All Users dir are variable directories in windows. Details can be found in the document about KNOWNFOLDERIDs (CSIDL in older versions).
Because this values are system dependent Java does not provide a way to access the values.
I think there is in general no equivalent on other operating systems to this windows specific folder. In addition the folder Documents & Settings\All Users is only present in latest windows versions and things are handled differently for e.g Windows 2000 or XP I think.
If you really need this information you should read the microsoft docs and impement a native library or some script invoked by Runtime.exec to provide the information to your java application.