Last Accessed Time of any file in Android

You can get the last access time using stat or lstat. The two methods, android.system.Os.stat(String path) and android.system.Os.lstat(String path), were made public in Android 5.0. On previous Android versions you will need to use reflection or run a command in a shell.

Usage:

Android 5.0+

java

long lastAccessTime = Os.lstat(file.getAbsolutePath()).st_atime;

Using reflection before Android 5.0

java

Class<?> clazz = Class.forName("libcore.io.Libcore");
Field field = clazz.getDeclaredField("os");
if (!field.isAccessible()) {
  field.setAccessible(true);
}
Object os = field.get(null);

Method method = os.getClass().getMethod("lstat", String.class);
Object lstat = method.invoke(os, file.getAbsolutePath());

field = lstat.getClass().getDeclaredField("st_atime");
if (!field.isAccessible()) {
  field.setAccessible(true);
}
long lastAccessTime = field.getLong(lstat);

Note:

I don't think last access time is used on Android. From the java.nio documentation:

If the file system implementation does not support a time stamp to indicate the time of last access then this method returns an implementation specific default value, typically the last-modified-time or a FileTime representing the epoch (1970-01-01T00:00:00Z).

I tested changing the last access time using the following command:

java

touch -a [PATH]

This did change the last access time when I ran the command as the root user. However, I don't think the last accessed time is updated/used on Android.