J.A.V.A. Mail Reader Design Document

Winter Quarter 1996
2/9/96

Document Author:

Project Sponsors:

The Just Another Version of Anarchy Team:

Brice Wilson (Manager/Programmer)
Jay Bredenberg (Architect)
Aaron Sims (Manager/Architect)
John Stevens (Programmer)
Joel Furnsinn(Technical Writer)

1.0 Project Description
2.0 High-Level Architecture
3.0 Design Specification
4.0 Class Descriptions
5.0 User Interface

1.0 Project Description

Click Project Description for the project description.

2.0 High-Level Architecture

Figure 1: High Level Architecture of JAVA Mail Application

The JAVA applet is a means for users to gain access to their mailboxes from any location where they have access to the World Wide Web and Netscape 2.0 or other Java Beta capable browser. The benefit of using the IMAP architecture is that it allows you to read mail messages without downloading them to the local client. Therefore when a user switches between machines to check their mail, they don't have to worry about whether a certain message they need to read/reread is on that particular machine.

To access the JMail application, the user needs to access two things: a Java Beta capable browser (Netscape 2), and an IP connection to a network that has an IMAP/web server connected to it. Initially, the user makes an HTTP request for the address of the JMail application (which currently resides at http://www-int.cc.gatech.edu/classes/CS3302.winter.96/java/ . On the web server (which is also the IMAP server), there resides the JMail applet for the user to access. When the user goes to the location of the JMail applet, the applet is downloaded to the machine that the user is running. From this point, the user has the JMail binary on his/her machine, and the Java browser executes the JMail binary. If any mail information is required, the JMail binary makes a request via Ian Smith's Non Dairy Creamer package to the IMAP server. The JMail application will also need to access mail information on the local file system via folders. These requests access data through the NDC package also, but will utilize the local file system.

But what happens from the server's view? There are two type of requests to the server that we are concerned with: IMAP, and HTTP protocol requests. The HTTP requests that we are going to take advantage of are those that request the Java executable binary be sent to the client. When theses are received, the server will send the executable to the Netscape client via the HTTP protocol. The IMAP requests that come in are handled by the IMAP daemon. When they are recognized, the IMAP daemon goes to the file system to retrieve the requested information. The server then waits for another request from any IMAP client.

3.0 Design Specification

The primary design work we needed to complete was in the area of the interface. Ian Smith's Non Dairy Creamer classes were used to access the data that was needed to display to the user. To describe the classes we developed for the JMail reader, the Coad/Nicola OOA representation was used.

To better understand the classes we developed, it is best to read the AWT classes that serve as the parents to the classes that were written.

Figure 2: Object Representation of JAVA Interface Classes

4.0 Class Descriptions

In addition to the decription of these classes, the class definitions produced by JavaDoc can be found in the Guide to the Source Code for the JMail project.

Desktop_Frame

(Subclass of Object.Component.Container.Window.Frame)

Constructors
- Desktop_Frame(): creates the desktop frame
Methods
- public int initialize_physical() searches the local file system for existing folders (such as a ./Mail directory) and creates a physical representation of the folder on the desktop and an instance of a physical folder
- public int initialize_virtual() reads in the configuration email and if it exists, creates a virtual folder representation on the desktop, as well as generating a new instance of the Virtual_Folder class

JMail_Frame

(Subclass of Object.Component.Container.Window.Frame)

Attributes
- public int background_color
Methods
- public int add_button (int x, int y, String Button_Title, String Frame_Name) adds a button to the specified frame at the x, y coordinates sent in as parameters, and places the button text on the button
- public int add_label (int x, int y, String Label_Text, String Frame_Name) adds the form title label to the specified form and at the location passed into the add_label method.
- public int add_logo (int x, int y, String Frame_Name) adds the J-Mail logo to the frame Frame_Name at the specified x, y location

FolderList_Frame

(Subclass of JMail_Frame)

Attributes
- public int Mailbox_ID
- public String Mailbox_String
Constructors
- FolderList_Frame (String FolderName) creates the FolderList_Frame and puts the FolderName on the Title Bar of the frame
Methods
- public int initialize() fills in the list box with the name of all available physical folders
- choose_folder(int index) sends the message to the chosen folder from the old folder and deletes the message from the previous folder

Folder

(Part of Desktop_Frame)

Attributes
- public String Name
- public int Mailbox_ID
Constructors
- Folder(String Name) creates a new folder and puts the title under the bitmap representation
Methods
- public int drag() drags the bitmap representation of the folder around the desktop window

Virtual_Folder

(Subclass of Folder)

Attributes
- vector int Message_Index
Constructors
- Virtual_Folder (String Name) creates a new virtual folder representation on the desktop and puts the name under the bitmap image

For a description of what a virtual folder is, please see the requirements document.