Setting file permissions returns FALSE always
Solution 1
I found the solution and will answer my own question:
When setting permissions on file or directory, you first MUST actually create the directory or write the file and only then set the permissions.
So, what I was doing at start was wrong:
File dir = new File(path);
boolean rc1 = dir.setExecutable(true, false);
While actually need to:
File dir = new File(path);
dir.mkdirs();
boolean rc1 = dir.setExecutable(true, false);
boolean rc2 = dir.setReadable(true, false);
boolean rc3 = dir.setWritable(true, false);
or
File f = new File(uploadedFileLocation);
ImageIO.write(image, "jpg", f);
boolean rc1 = f.setExecutable(true, false);
boolean rc2 = f.setReadable(true, false);
boolean rc3 = f.setWritable(true, false);
Then it will work :)
Solution 2
from javadocs
setExecutable(): Returns
true if and only if the operation succeeded. The operation will fail if the user does not have permission to change the access permissions of this abstract pathname. If executable is false and the underlying file system does not implement an execute permission, then the operation will fail.
Also,
File(String pathname) Creates a new File instance by converting the given pathname string into an abstract pathname. It creates a file instance. It does not create a new file.
To create a new file
File f;
f=new File("myfile.txt");
if(!f.exists()){
f.createNewFile();
System.out.println("New file \"myfile.txt\" has been created
to the current directory");
}
Solution 3
Maybe you are not running this as a Super User in Linux. It can be the case that you(Logged in as) itself don't have rights to give file permissions.
urir
Updated on June 03, 2022Comments
-
urir almost 2 years
The code:
File dir = new File(path); boolean rc1 = dir.setExecutable(true, false); boolean rc2 = dir.setReadable(true, false); boolean rc3 = dir.setWritable(true, false); if (!rc1 || !rc2 || !rc3){ logger.warn("One of the permissions set returned false: rc1="+rc1+" rc2="+rc2+" rc3="+rc3 + " [for dir '"+dir+"']"); }
On Ubuntu all 3 calls return false. On my Windows only the 3rd call to setWritable returns false.
The target is to create the file/dir so the user (tomcat) and the group will be able to read/write.
BUT the file created on Ubuntu without permissions for the group to write. -
urir over 11 yearsCorrect, this is not super user. This is 'tomcat' user for running Tomcat. User is part of other Group X. While creating directory and file we want to give permission to other users in the group X to this file.
-
urir over 11 yearsIf I login with this user then in command line I have permission to change it.
-
urir over 11 yearsAlso: same is correct both for creating the dir and same call for creating the file in dir.
-
Bhavik Shah over 11 yearsalso try changing the umask on ubuntu