eecs4413-2021f / module-b

EECS 4413: Building E-Commerce Systems (Fall 2021) - Code examples from Tomcat & Web Services module (Weeks 3 & 4).

Module B - Web Services

• HTTP Server Refactoring Example
  • Other Servlets
    • From the Lab
  • RESTful Products API Example
    • From the Lab
  • Miscellaneous
  • Common Gateway Interface
    • Bash Scripts:
    • PERL Scripts:

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HTTP Server Refactoring Example

	Description
v1.0	The initial code with everything in the run method.
v1.1	The business logic/application code is moved into a doRequest method.
v1.2	The request and response variables are grouped into Request and Response classes.
v1.3	The doRequest is removed for the HTTPServer class entirely into a subclass MainService.
v2	The Request and Response classes and the request and response handling methods are moved into dedicated RequestContext and ResponseContext classes.
v3	Split each service into its own class, and group the server code into its own package.
v4	Reorganize the server code so the server itself isn't a thread. Clients are handle by worker threads.
v5	Spin-off the service logic into model classes, engines, and data access objects.

The Tomcat servlet versions:

• HelloService
• CalcService
• CalcOpService
• StudentsService

The associated model classes:

• CalcEngine
• StudentsDAO
• Students
• Student

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Other Servlets

• TotalService: Demonstrates accessing and setting the session.

From the Lab

• StartService: Demonstrates redirection, the session, querying request properties and initial parameters.
• VendorIDtoNamesService: Demostrates the session, uses a TCP service via model (engine) class.
  • VendorIDtoNameTCPService: The TCP service.
  • VendorsEngine: The model class (engine).

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RESTful Products API Example

• ProductsAPIService: The Products API
  • Product: Model class for representing a record in the Product table in the database.
  • Products: Model class for a collection of Product objects.
  • ProductFilter: Model class for storing parameters for the search filter.
  • ProductsDAO: Database access object for CRUD operations into the database.
  • ProductsAPIRequest: Class to check and parse the JSON request bodies into Product and Products.
  • ProductsAPIResponse: Class to form well-structured JSON responses specific to the Products API.

From the Lab

• CartAPIService: The Cart API

  • CartAPIRequest: Class to check and parse the JSON request bodies into ProductFilter objects.
  • CartAPIResponse: Class to form well-structured JSON responses specific to the Cart API.

• Shared:

  • APIRequest: Class to deserialize the HTTP Request body as JSON.
  • APIResponse: Class to form well-structured JSON responses.
  • context.xml: Database configurations

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Miscellaneous

• HTTPClient

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Common Gateway Interface

To run, copy the cgi-bin directory into your www directory and run: chmod -R go+x ~/www/cgi-bin/.

Bash Scripts:

• hello.cgi
• environment.cgi

PERL Scripts:

• hello.pl
• environment.pl
• redirect.pl
• webpage.pl