JTree, displaying data from a database

Question

Hi, im doing an application that will display the listing of courses, and allow users to book them. For the display of courses, i plan to use JTree to display them.
However my problem arises from fetchin data and putting them into the tree.
This file connects to the database and fetch the 'Course Category' and puts it in an Array.
public ArrayList<CourseCategory> getCategory() {
ArrayList<CourseCategory> categoryArray = new ArrayList();
try {
String statement = "SELECT * FROM Category";
rs = stmt.executeQuery(statement);
while (rs.next()) {
CourseCategory cc = new CourseCategory();
cc.setCategoryID(rs.getInt("CategoryID"));
cc.setCategoryName(rs.getString("CategoryName"));
categoryArray.add(cc);
rs.close();
stmt.close();
con.close();
catch (Exception e) {
//catch exception     }
return categoryArray;
CourseCategory File has the necessary accessor methods, and a toString method to display out the category name.
The main file, which has the JTree
public DisplayCoursesGUI() {
try {
courseDB = new CourseDB();
courseDB.getCategory();
catch (Exception e) {
//catch exception }
DefaultMutableTreeNode top = new DefaultMutableTreeNode("");
for (int i=0;i<courseDB.test2().size();i++) {
category = new DefaultMutableTreeNode(courseDB.getCategory());
top.add(category);
Codes for JTrees as follows.
I have the output of
e.g.
[MICROSOFT OFFICE APPLICATIONS, WEB APPLICATIONS] repeated twice in the tree. Im hoping to achieve the following effects
e.g.
-MICROSOFT OFFICE APPLICATIONS
----Microsoft Word
----Microsoft Powerpoint
-WEB APPLICATIONS
-----Adobe Photoshop
I have 2 MS Access Table.[Category]ID, CategoryName. [COURSE]ID,CourseName,CategoryID. They have a relationship.
How do I modify my codes to get what i hope to achieve? Help really appreciated.
Thank you!!

Answer 1

Hi,
If you read my first post, I wanted to achieve this effect.
----CategoryName1
----------SubCategoryItem1
----CategoryName2
----------SubCategoryItem2
My Table Structure.
CATEGORY TABLE
ID (autonumber), Name(string)
COURSES TABLE
ID(autonumber),Name(string), CategoryID(int)(A Relationship is link to Category Table-ID)
I have managed to retrieve the items from the Category Table into a result set, and I have added the result set into an Array (See 1st post)
Now, the problem comes when im tryin to do a for loop to display out the categorynames from the array(see 1st post again).
Now my array prints out as follows
e.g.
[CategoryName1,CategoryName2]
And if i put a for look into my application to display a JTREE,
My end results is
------[CategoryName1, CategoryName2]
------[CategoryName1, CategoryName2]
How should I ammend my codes to get:
-------CategoryName1
-------CategoryName2