Directory listener in Java

Question

I have an application in which I want to listen to any changes made to a particular directory. The application should ping me as soon as there are any files added, deleted

Answer 1

Jnotify for file notification in java. Code sample

   public void sample() throws Exception {
        // path to watch    
        String path = System.getProperty("user.home");    
        // watch mask, specify events you care about,    
        // or JNotify.FILE_ANY for all events.    
        int mask = JNotify.FILE_CREATED  |                
        JNotify.FILE_DELETED  |                
        JNotify.FILE_MODIFIED |                
        JNotify.FILE_RENAMED;    
        // watch subtree?    boolean watchSubtree = true;    
        // add actual watch    
        int watchID = JNotify.addWatch(path, mask, watchSubtree, new Listener());    
        // sleep a little, the application will exit if you    
        // don't (watching is asynchronous), depending on your    
        // application, this may not be required    
        Thread.sleep(1000000);    
        // to remove watch the watch    
        boolean res = JNotify.removeWatch(watchID);    
        if (!res) {      
            // invalid watch ID specified.    
            }  
        }  
    class Listener implements JNotifyListener 
    {    
        public void fileRenamed(int wd, String rootPath, String oldName,        
                String newName) {      
            print("renamed " + rootPath + " : " + oldName + " -> " + newName);    }    
        public void fileModified(int wd, String rootPath, String name) 
        {      print("modified " + rootPath + " : " + name);    }    
        public void fileDeleted(int wd, String rootPath, String name) {      
            print("deleted " + rootPath + " : " + name);    }    
        public void fileCreated(int wd, String rootPath, String name) {      
            print("created " + rootPath + " : " + name);    }    
        void print(String msg) {      
            System.err.println(msg);    }  
        }