Project 3 - HTTP Server

Due - Thursday, November 4, 2021 - 9:55am

For this project, you will implement an HTTP server, two web applications, and a full suite of tests. You will practice using the following:

• Concurrency and threads
• Sockets
• JUnit and testing
• Remote deployment
• Good design practices

Part 1 - HTTP Server

For Part 1 of this assignment you will implement an HTTP server.

Requirements

1. You must use raw sockets for this assignment. You may not use Tomcat, Jetty, or any other existing server. You also may not use any external libraries for request parsing, etc.
2. Your server must support GET and POST requests. Any other HTTP method will result in a 405 Method Not Allowed status code. See HTTP Status Code Definitions.
3. Your server must return well-formed XHTML. Note: empty elements must always be closed.
4. Your server must be flexible enough to support different web applications.
5. Your server will be multithreaded. Each incoming request will be handled by a different thread.

Recommended Design

It is recommend you follow a design similar to the design supported by Jetty. Your design does not need to follow the exact API nor does it need to be as extensive, however I recommend you borrow similar ideas. Here are a few items to consider:

• Create a Handler interface with a handle method. Each web application will implement a different set of handlers, for example a search application will support a SearchHandler and a chat application would have a ChatHandler.
• Support an addMapping method that will map a URI path to a specific Handler instance. When a new request is made to the server the server will retrieve from the mapping the Handler appropriate for the path in the request URI.

The examples below show how my API is used for the required applications below.

public class SearchApplication {
	public static void main(String[] args) {
		int port = 1024;
		HTTPServer server = new HTTPServer(port);
		//The request GET /reviewsearch will be dispatched to the 
		//handle method of the ReviewSearchHandler.
		server.addMapping("/reviewsearch", new ReviewSearchHandler());
		//The request GET /find will be dispatched to the 
		//handle method of the FindHandler.
		server.addMapping("/find", new FindHandler());
		server.startup();
	}
}

public class ChatApplication {
	public static void main(String[] args) {
		int port = 1024;
		HTTPServer server = new HTTPServer(port);
		server.addMapping("/slackbot", new ChatHandler());
		server.startup();
	}
}

Part 2 - Search Application

For Part 2 of this assignment you will implement an application that will allow users to search the InvertedIndex you built for Project 1. You will deploy this application on your microcloud VM on port 8080.

You will support the following four APIs:

GET /reviewsearch

This request will return a web page containing, at minimum, a text box and button. When the user enters a query in the text box and clicks the button the POST method described below will be called.

POST /reviewsearch

The body of this request will look as follows: query=term where the value is a URL-encoded string.

You will return a web page listing all of the review search results.

GET /find

This request will return a web page containing, at minimum, a text box and button. When the user enters a message in the text box and clicks the button the POST method described below will be called.

POST /find

The body of this request will look as follows: asin=123456789 where the value is a URL-encoded string.

You will return a web page listing all of the review and qa documents with the provided ASIN.

Part 3 - Chat Application

For Part 3 of this assignment you will implement an application that will allow a user to anonymously post a message to the Slack team. Refer to the Accessing the Slack API instructions for pointers. You will deploy this application on your microcloud VM on port 9090.

You will support the following two APIs:

GET /slackbot

This request will return a web page containing, at minimum, a text box and button. When the user enters a message in the text box and clicks the button the POST method described below will be called.

POST /slackbot

The body of this request will look as follows: message=test+message where the value is a URL-encoded string.

This request will trigger a post of the message specified by the body to the Slack channel #project3. Regardless of the user who types the message it will always appear to have come from your application.

You may choose what to return to the client. One option is to return a web page with a confirmation, and another option is to return the same page returned by the GET request so that the user may post another message.

Part 4 - Tests

For Part 4 you will submit all test cases you have written to test your solution. You must demonstrate unit tests, integration tests, and system tests.

It is expected that all tests execute through JUnit, however if you choose to write standalone client programs for your system tests you may submit those as well, along with a README that describes how they should be executed.

Your grade for Part 4 will be based on the completeness of your tests. If you implement only the tests given as examples below you will not earn a high grade for this portion.

Unit Tests

Unit tests will test one method. It is not required that you have unit tests for every method you implement, however methods that perform complex processing or logic should have one or more associated unit tests. As an example, you may have a method that parses an HTTP request to validate that it has a correct format, valid method, etc. You should implement several unit tests to confirm that the method works correctly when the request is valid and in all scenarios when it is invalid.

Integration Tests

Integration tests generally test a path of execution through your program. You may, for example, have a handler that takes as input a request and then calls another method to post to to Slack. In this case, you could use a mock request object and test that passing that mock object to your handler results in a correct post to Slack.

System Tests

System tests will test the end-to-end execution of your program. A system test would use a client program to make a request (valid or invalid) of your deployed server and verify that the response is correct.

Other Advice

1. You may limit the size of the InvertedIndex used in Part 2 to 10,000 records.
2. It is strongly recommended that you implement thorough logging in your solution. This will help you debug. Your logs should indicate which requests were made to your server and where your server went wrong.
3. Consider using curl or another client program to perform initial tests on your deployed solution. Below are a few requests to get you started.

# correct GET /reviewsearch
curl -v "http://<host>:<port>/reviewsearch"

# correct POST /reviewsearch
curl -v -X POST --data-urlencode "query=computer" "http://<host>:<port>/reviewsearch"

# incorrect POST /reviewsearch
curl -v -X POST --data-urlencode "BADquery=computer" "http://<host>:<port>/reviewsearch"

External Libraries

The only external libraries you may use for this assignment are GSON, Apache Log4j and JUnit. For this assignment, it is your responsibility to set up the pom.xml file correctly.

Team Option

Requests to work in a team of no more than two students will be considered. No one may work as a team until your request is formally approved by the instructor. If you are interested in a team option both members of the team must come to office hour on Oct 20 or 21 with a proposed work distribution and collaboration plan. The instructor will approve or decline requests made by October 21.

Submission

1. Use the following link to create your private github repository for this assignment: Project 3. Note, the repository is completely empty so you will need to set it up as required by the assignment.
2. For full credit, make sure to follow all Style Guidelines. Points will be deducted for each violation.
3. All code and the jar file described above must be submitted to your github repository by Thursday, November 4, 2021 - 9:55am. Failure to submit the project as required will result in a score of 0.
4. There will be no interactive grading for Project 3. Instead, grading will occur as follows:
   • After the deadline the instructor will execute a client program that will perform one or more tests for each of the Functionality Criterion described in the Project 3 assignment specification.
   • If a student's solution is not deployed and running on the microcloud VM node specified in the assignment when the tests are executed that student will earn a score of 0 for all Functionality Criterion. The tests may be executed anytime after the deadline and it is expected that a student's continue to run and function correctly until the instructor indicates it is safe to stop the process. A solution that is not deployed correctly will not be eligible for Design resubmission for this project.
   • If a student's solution is deployed and running but does not correctly implement the APIs required the student will earn only partial credit for the Functionality Criterion. In this case, the student will not be eligible for Design resubmission for this project.
   • An instructor or TA will review all code, including the Part 4 test code, and assign a Design grade. Students who pass all Functionality tests and have not already completed two project resubmissions will be eligible for resubmission of Project 3.

Grading Rubric

Points	Criterion
5	Functionality - Part 2 Server: correct GET /reviewsearch.
5	Functionality - Part 2 Server: correct POST /reviewsearch.
5	Functionality - Part 2 Server: error conditions GET /reviewsearch.
5	Functionality - Part 2 Server: error conditions POST /reviewsearch.
5	Functionality - Part 2 Server: correct GET /find.
5	Functionality - Part 2 Server: correct POST /find.
5	Functionality - Part 2 Server: error conditions GET /find.
5	Functionality - Part 2 Server: error conditions POST /find.
2.5	Functionality - Part 3 Server: correct GET /slackbot.
2.5	Functionality - Part 3 Server: correct POST /slackbot.
2.5	Functionality - Part 3 Server: error conditions GET /slackbot.
2.5	Functionality - Part 3 Server: error conditions POST /slackbot.
25	Design - Part 1 Server design.
15	Design - Part 4 completeness of test cases.
5	Design - Github usage and commit history.
5	Design - Meets all style guidelines.

Academic Dishonesty

Any work you submit is expected to be your own original work. If you use any web resources in developing your code you are strongly advised to cite those resources. The only exception to this rule is code that is posted on the class website. The URL of the resource you used in a comment in your code is fine. If I google even a single line of uncited code and find it on the internet you may get a 0 on the assignment or an F in the class. You may also get a 0 on the assignment or an F in the class if your solution is at all similar to that of any other student.