Architecture: Bridge Design Pattern

Hi Friends,
I have made a project of “Remote Control Application” by implementing Bridge design pattern.

Project: Solves the problem of dependency / coupling between parallel development / evolution of 2 different components by creating a bridge between their interfaces 😉

What is Bridge Design Pattern: decouples an abstraction so two classes can vary independently

Github project code: https://github.com/premaseem/DesignPatternsJava9/tree/bridge-pattern

I have written the working code based on the Architectural diagram, which can be downloaded from Github.

MongoDB : History tracking micro service

Mongo DB local -> oplog.$main collection keeps records of all changes which happen in the primary database, which are eventually read by secondaries to catch up data or syncup data in the mongo replica set.

A micro service can be written, which can pull up data / delta form oplog.$main based on the name space ( defined db and collection) and can save that data in destination Db or audit DB.

Later on audit DB can the queried to fetch the history or log data pertaining to entity.

Architecture: How mongodb replication works and secondary node get data from primary node

Here is the simple diagram which explains how the middle man oplog watches/monitors primary and pull any new operation or changes happened on primary and records them in oplog, which eventually get read by all secondaries to update them selves.

1. insert operation happened in primary
2. Operation got logged in oplog ( which is part of local db – oplog.$main )
3. Secondary reads data from oplog and update them selves.

Architecture: Facade design pattern

Hi Friends,
I have made a project of  “All in one remote controller”  by implementing Facade design pattern.

Project: Solves the problem of too many TV / entertainment unit remotes by using a simplified master remote control ( which acts as Facade here )

What is Facade Design Pattern: provides a simple interface to a more complex underlying object.

Github project code: https://github.com/premaseem/DesignPatternsJava9/tree/facade-pattern

I have written the working code based on the Architectural diagram, which can be downloaded from Github.

 

 

 

Architecture: Adapter design pattern

Adapter Design Pattern allows for two incompatible classes to work together by wrapping an interface around one of the existing classes

I have written the working code based on the Architectural diagram, which can be downloaded from Github.

Working code github link: https://github.com/premaseem/DesignPatternsJava9/tree/adapter-pattern

 

 

Architecture: Proxy design pattern

I have written the working code based on the Architectural diagram, which can be downloaded from Github

Working code github link:  https://github.com/premaseem/DesignPatternsJava9/tree/proxy-pattern