asked on

Won't count files in a directory

I'm trying to count the number of files in a directory, to determine navigation. Here's what I have:

<%@page contentType="text/html" import="java.io.*"%>

<%
//Get the parameters
String courseId = request.getParameter("courseid");
int chapter = Integer.parseInt(request.getParameter("chapter"));
int pageIndex = Integer.parseInt(request.getParameter("page"));
String state = request.getParameter("state");

//Get the number of pages for the current chapter

String directory = courseId + "\\" + chapter;
int currentChapPages = 0;
File chapPages = new File(directory);
if (chapPages.isDirectory()) {
currentChapPages = chapPages.listFiles().length;
}

//Calculate the next and previous chapter & page
int prevChapter = chapter;
int prevPage = pageIndex - 1;
int nextChapter = chapter;
int nextPage = pageIndex + 1;
boolean showNextButton = true;
boolean showPrevButton = true;

//If the current page is the last page, go to the next chapter and first page
if (pageIndex >= currentChapPages) {
nextChapter++;
nextPage = 1;

//Make sure there is a next chapter, if not don't show next button
String directoryPrev = courseId + "\\" + chapter;
int prevChapPages = 0;
File prevPages = new File(directoryPrev);

if (prevPages.isDirectory()) {
prevChapPages = prevPages.list().length;
}
else {
showNextButton = false;
}
}

//If it is the first page, go to the previous chapter except for the How-To (98)
if (pageIndex <= 1 && chapter != 98) {
prevChapter--;

//If the the scope is beyond the first chapter, go to the foreword (99)
if (prevChapter <= 0) {
prevChapter = 99;
}

//Find the last page of the previous chapter if it is not the current chapter
//Set the prev page to the last page in the previous chapter
if (prevChapter != chapter) {
String directoryPrev = courseId + "\\" + chapter;
int prevChapPages = 0;
File prevChapList = new File(directoryPrev);
if (prevChapList.isDirectory()) {
prevChapPages = prevChapList.list().length;
}
prevPage = prevChapPages;
}
}
%>

Seems like it should work, but if I print out the value of currentChapPages or prevChapPages I get zero. If I declare the variable without assigning it an initial value, it throws a 500 saying "The variable "currentChapPages" may be accessed here before having been definitely assigned a value." We're running JRun 3.0 on IIS 5. Anyone have any ideas why I can't get a value out of the currentChapPages bit?

ASKER CERTIFIED SOLUTION

kennethxu

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

umangjoshi

create a File object refer a directory
File fdir = new File("path/url to dir");

the following returns name of files or directory
String files[] = fdir.list();

tigerjade_nc

ASKER

The path's correct. I tried making it full relative as well as absolute, and still didn't get any closer. The currentChapPages & prevChapPages variables still return zero, no matter what's in the directory. Neither of these suggestions worked with this bleeping thing. :( Anything else I might have missed? Thanks for the efforts, y'all.

tigerjade_nc

ASKER

I found a weird work-around. I moved the files to another level, and now it's counting! Thanks, y'all!

kennethxu

>> I found a weird work-around. I moved the files to another level
I swear that your path is pointing to the right place, and I would never use filesystem relative path, because it is different from server to server. if you must use relative path, use your webapp's relative path with application.getRealPath method as I suggested.

Thanks for your points and good luck :)

kennethxu

>> I swear that your path is pointing to the right place
i mean "NOT pointing", sorry :)