Java OCA OCP Practice Question 2194

Question

Assume the /environment directory exists and contains a file with a symbolic link to the /environment directory.

In addition, assume all files within the directory are fully accessible.

What is the result of executing the following program?. 

import java.nio.file.*; 
import java.nio.file.attribute.*; 
public class Main { 
   public static void accessFile(Path p, long timeEpoch) { 
      try { /*www  .  j  a v  a 2 s.c om*/
         Files.readAttributes(p, BasicFileAttributes.class) 
            .setTimes(null, null, FileTime.fromMillis(timeEpoch)); 
      } catch (Throwable e) { 
      } finally {} 
   } 
   public static final void main(String[] unused) throws Exception { 
      Path w = Paths.get("/environment"); 
      Files.walk(w) 
         .forEach(q -> accessFile(q,System.currentTimeMillis())); 
   } 
}
  • A. The code does not compile.
  • B. The program exits after successfully updating the creation time of files within the directory.
  • C. The program exits after successfully updating the last accessed time of files within the directory.
  • D. The program compiles but throws an exception at runtime.
  • E. The program enters an infinite loop and hangs at runtime.


A.

Note

The code does not compile because BasicFileAttributes is used to read file information, not write it, making Option A the correct answer.

If the code was changed to pass BasicFileAttributeView.class to the Files.getFileAttributeView() method, then the code would compile, and Option B would be the correct answer.

Finally, remember that by default, symbolic links are not traversed by the Files.walk() method, avoiding a cycle.

If FileVisitOption.FOLLOW_LINKS was passed, then the class would throw an exception because Files.walk() does keep track of the files it visits and throws a FileSystemLoopException in the presence of a cycle.




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