Java/JSP app to List Directories in a Drop Down

Question

Hi all! I'm a Java Newbie and have an application that was written in VB / ASP that I need to convert to Java / JSP. The app is relatively simple, however my understanding of Java is even more basic. :(
Here's what I need... The app needs to be able to read a directory structure on the web server and populated a drop down box on a JSP with the directory names. Then when one of the directories that are in the drop down are selected, the files within that directory are listed as HTML links to the actual files.
How do I get started?? Any sample code from people who have done this??
Thanks!
Teresa

Answer 1

Basically what you want to do is build a vector of objects that represent directories, and each "directory" object contains a vector of files as an attribute. This is done on the server side in a Servlet.
Then store all these objects in your session. Dynamically build your dropdown box to have an element for each directory. Use the JavaScript onSelect method to invoke another JSP that takes the number of the element selected, and displays all html links for the number that was passed in from the previous servlet.
For some about $150 I would write the whole thing for you, but here would be the server side code that builds a recursive directory list.
import java.io.*;
import java.util.*;
public class RecursiveDirectoryList {
     Vector Directories = new Vector();
     Vector Files = new Vector();
public RecursiveDirectoryList() {
     super();
public static void main(String[] args) {
String directoryName; // Directory name entered by the user.
File directory; // File object referring to the
//directory.
//TextIO.put("Enter a directory name: ");
directoryName = "C:\\docs";
directory = new File(directoryName);
if (directory.isDirectory() == false) {
// Program needs a directory name. Print an error message.
if (directory.exists() == false)
System.out.println("There is no such directory!");
else
System.out.println("That file is not a directory.");
else {
// List the contents of directory, with no indentation
// at the top level.
listContents( directory, "" );
} // end main()
static void listContents(File dir, String indent) {
// A recursive subroutine that lists the contents of
// the directory dir, including the contents of its
// subdirectories to any level of nesting. It is assumed
// that dir is in fact a directory. The indent parameter
// is a string of blanks that is prepended to each item in
// the listing. It grows in length with each increase in
// the level of directory nesting.
String[] files; // List of names of files in the directory.
System.out.println("Directory: " + dir.getAbsolutePath());
indent += " "; // Increase the indentation for listing the contents.
files = dir.list();
for (int i = 0; i < files.length; i++) {
// If the file is a directory, list its contents
// recursively. Otherwise, just print its name.
File f = new File(dir, files);
if (f.isDirectory())
listContents(f, indent);
else
System.out.println("File: " + dir.getAbsolutePath() + "\\" + files[i]);
} // end listContents()