oop_lab13's Introduction

Lab 13. Visitor & Proxy

Description

A simple example of the Visitor and Proxy patterns.

Task

Check what is Celery. Run app.py to understand why do we need Celery.
Setup Flask-Celery demo from GIT. Use test.http to explore.
Check the documentation of Stamping API in Celery. Investigate Stamping API source code.
Complete Task 1.
Test JSOUP and how to scrape websites.
Check how to send raw HTTP requests. Check PDL example.
Complete Task 2.
Submit a link to GitHub with tests and a GitHub Action file.

Task 1

Implement Stamping API in Java. The goal is to reimplement Stamping API in Java for a simplified framework. The framework consists of:

interface Task, an interface of building unit;
class Signature that represents the smallest unit in framework and single task invocation;
class Group that represents the list of signatures, and when the group is called, the tasks will be applied one after another in the current process.
You need to implement Stamping API and Group Stamping in a similar manner as it is done in Celery. When the apply method is called for Group Stamping, there should happen an automatic stamping of the Signature with the groupId. Stamps are stored in the group header.

Task 2

Implement scrapping service for NewHomeSource with Proxy template. If the link is already scrapped extract it from the cache, else run the link again. Use the JDBC library to store links in SQLite DB. Use JSoup to parse HTML, if needed.