displaying the number of times a page has ever been accessed

[April Benzine]

Hi all,
I can't figure out how do the code for displaying how many times my page has ever been accessed. here is my code I have so far. historyNum is an instance variable.

public synchronized void writeNumToFile() {
historyNum ++;
try {
in = new BufferedReader(new FileReader("c:\\projects\\src\\java146\\project3\\visitHistory.dat"));
} catch (FileNotFoundException fnfe) {
System.out.println("File not found.");
fnfe.printStackTrace();
} catch (IOException fnfe) {
System.out.println("Cannot read file.");
fnfe.printStackTrace();
}


}


Thank you!!

[April Benzine]

I don't think I explained this very well.
suedocode:
-use file to store number
-init method
-open history file and read data (just contains a number)
-private int historyNum
-public synchronized void writeNumToFile(){
-increment
-open file
-write to file
-close file
}

[Jeanne Boyarsky]

April,
A BufferedReader is for reading. You need to use a BufferedWriter to write out the result. Note that doing the file I/O inside a synchronized block is slowing the number of hits to the servlets and not recommended.

[Jeroen Wenting]

better use a memory cache for the number and update the file only during server shutdown. You may elect to have a separate thread update the file more often (say once an hour) to prevent data loss in case the server goes down without writing the file (read: server crashes).

That way your code will perform a lot better.
Not making it synchronised may mean your count may be a bit low during heavy traffic as maybe a few updates are missed but that's almost certainly worth the price.

[Fisher Daniel]

Hi April,
I think it is better that our servlet doesn't access a directory in a computer. Because if your application is moved to another computer, you have to change the directory.

I agree with Jeroan Wenting, and you can then save the number into database when the server is shutdown.

Correct me if I am wrong
Hope this helps
daniel