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Android: How to get a file's creation date?

This is my code:

File TempFiles = new File(Tempfilepath);
if (TempFiles.exists()) {
    String[] child = TempFiles.list();
    for (in开发者_开发百科t i = 0; i < child.length; i++) {
        Log.i("File: " + child[i] + " creation date ?");
        // how to get file creation date..?
    }
}


The file creation date is not an available, but you can get the last-modified date:

File file = new File(filePath);
Date lastModDate = new Date(file.lastModified());

System.out.println("File last modified @ : "+ lastModDate.toString());


Here's how I would do it

// Used to examplify deletion of files more than 1 month old
// Note the L that tells the compiler to interpret the number as a Long
final int MAXFILEAGE = 2678400000L; // 1 month in milliseconds

// Get file handle to the directory. In this case the application files dir
File dir = new File(getFilesDir().toString());

// Obtain list of files in the directory. 
// listFiles() returns a list of File objects to each file found.
File[] files = dir.listFiles();

// Loop through all files
for (File f : files ) {

   // Get the last modified date. Milliseconds since 1970
   Long lastmodified = f.lastModified();

   // Do stuff here to deal with the file.. 
   // For instance delete files older than 1 month
   if(lastmodified+MAXFILEAGE<System.currentTimeMillis()) {
      f.delete();
   }
}


The file creation date is not an available piece of data exposed by the Java File class. I recommend you rethink what you are doing and change your plan so you will not need it.


Starting in API level 26, you can do this:

File file = ...;
BasicFileAttributes attr = Files.readAttributes(file.toPath(), BasicFileAttributes.class);
long createdAt = attr.creationTime().toMillis();


There is an alternate way. When you open the file for the first time save the lastModified date, before you modify the folder.

long createdDate =new File(filePath).lastModified();

And then when you close the file do

File file =new File(filePath);
file.setLastModified(createdDate);

If you have done this since the file was created, then you will have the createdDate as the lastModified date all the time.


Having backward compatibility in mind I would rather use the following:

fun getLastModifiedTimeInMillis(file: File): Long? {
    return try {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            getLastModifiedTimeFromBasicFileAttrs(file)
        } else {
            file.lastModified()
        }
    } catch (x: Exception) {
        x.printStackTrace()
        null
    }
}

@RequiresApi(Build.VERSION_CODES.O)
private fun getLastModifiedTimeFromBasicFileAttrs(file: File): Long {
    val basicFileAttributes = Files.readAttributes(
        file.toPath(),
        BasicFileAttributes::class.java
    )
    return basicFileAttributes.creationTime().toMillis()
}

alternatively, if you are dealing with jpg, jpegs you can use ExifInterface

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