COMP2396B代写、Java程序语言调试、Java代做、server program代写

日期：2019-04-26 11:02

COMP2396B - Assignment

Due: 3rd May, 2019 23:55

Introduction

This assignment tests your skills on writing networking and multi-threading program in Java.

You are required to write a peer-to-peer (P2P) images sharing system. A hybrid P2P structure

is used in this assignment, where a server is used as the source of images as well as that of the

list of peers available. In this assignment, you have to integrate the program written in

Assignment 3 and Assignment 4 to complete this assignment.

You need to write two main programs. ImageServer.java is the server program, and

ImagePeer.java is the client (peer) program. Notice that a server will also act as a peer to

share images.

Part I. Server interface

When ImageServer.class is executed, a file chooser should be presented to ask for an

image file. (Figure 1)

Figure 1: File chooser Figure 2: Server GUI

The image is then loaded and displayed as shown in Figure 2. If the image file fails to load,

the program terminates. Otherwise, the server should listen to the port 9000, and load the

“User.txt” which contains the user information into the program and waiting for user to login.

The “User.txt” is the file that generated by the assignment 3 authentication interface and

should include the following accounts for login:

Username: mqpeng Password: Comp2396B

Username: cjli Password: 2396BComp

Username: cbchan Password:HelloWorld0

The image should be resized and scaled to fit into a canvas of 700*700 pixels in size. The

button “Load another image” allows the user to change the current image. If the new image

fails to load, the old image is retained.

Part II. Peer program and authentication

When ImagePeer.javais executed, it should ask for the server’s IP address to be connected

to. It then asks the peer user to login. (Figures 3, 4 and 5). For the user authentication, you are

required to use the authentication module implemented in Assignment 3 as the interface.

The client should use the hash interface to hash the password before sending to the server and

the server need to verify the user information before starts the main GUI. Hence, the server

should also return the message if the user cannot login. (e.g. Account is locked)

Figure 3: Username input

Figure 4: Username input Figure 5: Password input

If the login is failed or locked, it should show an alert. (Figure 6)

Figure 6: Login alert

Figure 7: Peer GUI

Figure 7 Peer GUI

If the login is successful, an empty canvas should then be presented as shown in Figure 7. Like

the server, the canvas size in the peer should also be 700*700 pixels.

Immediately after the GUI is shown, the peer should connect to the server and start to download

the image from the server and other peers. Program should be terminated if it fails to connect to

the server. (See details below)

Part III: Peer initialization

The server should listen to port 9000 after initialization. The server has to maintain the

following:

1. The image, separated into blocks of 70*70 pixels in size

2. A list of active peers (the peer IP address and port number)

When a peer program is started, it should connect to the server at port 9000. The server

should then update the list of active peers, and each peer should collect the list of current

active peers from the server. This connection can be closed afterwards.

Part IV: P2P operation

Each peer should perform the following:

1. Try to download blocks of image from the list of peers in simultaneously.

2. Accept connection from other peers and send out blocks of images otherpeers

needed.

Notice that the server itself is a special peer that is the source of the image to be distributed.

Details about the suggested P2P operation will be introduced in the tutorial.

Part V: Update image

The image should be updated if:

1. If the user switches the image from the server program, all peers will change its image

immediately.

2. The user drags and drops the image block using the server program GUI. For such case, the

client only required to download the swapped image blocks.

Example execution

Execution result depends on how the P2P operation is implemented. Here is an example

of the execution behavior.

When the first peer starts (after the server), it starts

downloading blocks of image from the only peer

(the server) available.

When the second peer starts, it starts downloading

from the server peer (the bottom part) and the

first peer (the middle part).

Notice that since the first peer is also downloading

the blocks, the server is sending out blocks to the

two peers in an alternating manner so that the first

peer can download the other blocks from the second

peer.

The first peer will also start download from the

second peer.

Marking

- 85% marks are given to the functionality.

You may add additional classes, instant variables and methods to the project.

You may need to include and modify the classes implemented in assignment 3 for the

authentication function.

You will get part of the marks if you implemented some of the features.

A program that can run normally without throwing exceptions during runtime gets

higher marks.

Program with compile error will get 0 mark.

- 15% marks are given to your JavaDoc. A complete JavaDoc includes documentation

of every classes, member fields and methods that are not private. JavaDoc for the main

method may be omitted.

Submission

Please submit all source files (all *.java file and login information file) in a single compressed

file (in .zipor .7z) to Moodle. Please also include your generated ‘User.txt’ file. Late submission is

not allowed. Program with compile error will get 0 mark. (Please include any code that help

compile)

Program with no Javadoc will not be graded.

Do not submit .class file.

Plagiarism

Do not attempt plagiarism. We will check your program with software that checks program

structure. Both the source and the copying work will be penalized.

-- END --

When the user switches the image in the server, the

peers which choose to update the image will

download new blocks from the server and other

peers.