Program to demonstrate how to get and print last modification date of a file on the console in Java.  
Output of the program :
  
package com.hubberspot.code;
import java.io.File;
import java.util.Date;
public class ModifiedDate {
 public static void main(String[] args) {
  // Creating a new File Object by passing filename to it
  File file = new File("customer.txt");
  // Getting the last modified date by calling 
  // lastModified() method of the file object
  long modified = file.lastModified();
  // Creating a new date object by passing the modified long
  // value to its constructor
  Date lastModifiedDate = new Date(modified);
  // printing the initial modified date to the console
  System.out.println("Initial Modification Date : \n");
  System.out.println(lastModifiedDate);
  System.out.println("\nMaking the main thread sleep for 10 sec ... ");
  System.out.println("Till than modifying the file to print new modified date... ");
  try {
   Thread.sleep(10000);
  }
  catch (InterruptedException e) {
   e.printStackTrace();
  }
  // till main thread is at sleep for 10 sec 
  // we are modifying the file contents and saving
  // the file to print the new modified date 
  modified = file.lastModified();
  lastModifiedDate = new Date(modified);
  System.out.println("\nAfter Modification Date : \n");
  System.out.println(lastModifiedDate);
 }
}
Output of the program :
