Android:如何获取文件的创建日期？

Question

这是我的代码:

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

Answer 1

文件创建日期不可用,但您可以获取上次修改日期:

File file = new File(filePath);
Date lastModDate = new Date(file.lastModified());
Log.i("File last modified @ : "+ lastModDate.toString());

Answer 2

我就是这样做的

// 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();
   }
}

Answer 3

文件创建日期不是Java File类公开的可用数据.我建议你重新考虑你在做什么,改变你的计划,这样你就不需要了.

Answer 4

从API级别26开始，您可以执行以下操作：

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

Answer 5

还有另一种方式.在您修改文件夹之前,首次打开文件时保存lastModified日期.

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

然后当你关闭文件时

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

如果您在创建文件后已完成此操作,那么您将始终将createdDate作为lastModified日期.