How to rename a child directory in Java?-CodePudding

How can I rename a directory in java . I have a directory structure like /workspace/project-name/project/user/wbench/test/<multiple folders & git objects>

In the above structure I want to change test to dev (for example).

I thought Files.renameTo() will do the trick for me but this code is not working.

public ResponseMessage updateDirectoryName(String oldDirectoryName, String newDirectoryName, String userName) {
   File projectDirectoryForUser = gitUtils.getProjectDirectoryFromRepoName(userName, oldDirectoryName);

    try {
        if (projectDirectoryForUser.exists()) {
            File newDir = new File(projectDirectoryForUser.getParent() File.separator newDirectoryName);
            Boolean flag =projectDirectoryForUser.renameTo(newDir);
            if(flag){
                System.out.println("File renamed successfully");
            }else{
                System.out.println("Rename operation failed");
            }
        }
        else {
            log.info("No folder found for Project in file path");
        }

    }
    catch (Exception e){
        log.info("something is not right"   e.getMessage());
    }

My flag is always false and name of directory is not changed. I am certainly doing something wrong not sure what?

CodePudding user response：

On Windows a common cause of failure to rename directory names is when you have open file handles to a file inside the directory. If there is a current file handle Files.move(dir,newdir) will report AccessDeniedException and File.renameTo will return false for same paths.

So: Check you have closed all editors, file explorers, CMD.EXE / consoles / terminals / xterm / bash accessing the directory to move or one of its sub-directories and files.

Here is transcript of a test I made with my build directory moving "build" <=> "build.moved" with both calls. I get similar results for Windows and Linux with these commands:

jshell> Files.move(Path.of("build"),Path.of("build.moved"))
==> build.moved

jshell> new File("build.moved").renameTo(new File("build"));
==> true

jshell> new FileInputStream("build/AL.js")
$10 ==> java.io.FileInputStream@5d6f64b1

jshell> new File("build").renameTo(new File("build.moved"))
==> false

jshell> Files.move(Path.of("build"),Path.of("build.moved"))
|  Exception java.nio.file.AccessDeniedException: build -> build.moved
|        at WindowsException.translateToIOException (WindowsException.java:89)
|        at WindowsException.rethrowAsIOException (WindowsException.java:103)
|        at WindowsFileCopy.move (WindowsFileCopy.java:403)
|        at WindowsFileSystemProvider.move (WindowsFileSystemProvider.java:293)
|        at Files.move (Files.java:1432)
|        at (#12:1)

After closing the file, all is OK again:

jshell> $10.close()

jshell> Files.move(Path.of("build"),Path.of("build.moved"))
$15 ==> build.moved

jshell> new File("build.moved").renameTo(new File("build"))
$16 ==> true

As @VGR suggests, you get better error handling if you use Files.move and Path in place of File. If you use File, avoid String concatenation and File.separator by using the alternate constructor:

File newDir = new File(projectDirectoryForUser.getParent(), newDirectoryName);

CodePudding user response：

I think getParent() must be getParentFile() so you have the full path.

The newer generalisation of File, the class Path, together with the utilities class Files one should better use. Files.move is the equivalent of a File.renameTo and might not in every case work for non-empty directories.

public ResponseMessage updateDirectoryName(String oldDirectoryName,
        String newDirectoryName, String userName) {
    Path projectDirectoryForUser = gitUtils.getProjectDirectoryFromRepoName(userName,
            oldDirectoryName).toPath();

    try {
        if (Files.exists(projectDirectoryForUser)) {
            Path newDir = projectDirectoryForUser.resolveSibling(newDirectoryName);
            Files.move(projectDirectoryForUser, newDir);
            boolean flag = Files.exist(newDir);
            if (flag) {
                System.out.println("File renamed successfully");
            } else {
                System.out.println("Rename operation failed");
            }
        } else {
            log.info("No folder found for Project in file path");
        }

    } catch (Exception e){
        log.info("something is not right"   e.getMessage());
    }
}

Whereas File is a disk file, Path can also be from an URI, or a packed "file" in a zip file. Different file system views. This allows File to copy file or java resource into a zip, or rename a file in a zip. So for the same reason one uses List instead of an implementing ArrayList, one better use Path. Also I read that the Files operations are a bit better than those of File.

CodePudding user response：

You can't change a value os a final variable. Remove the "final" keyword from "projectDirectoryForUser" and try again.

See here