Learning
  • Software Engineering Golden Treasury
  • Trail Map
  • Caching
    • Alternatives to use before using cache
    • Caching Architecture
    • Cache Invalidation and Eviction
    • Cache Patterns
    • Cache
    • Consistency
    • Distributed Caching
    • Issues with caching
    • Types of caches
  • Career
    • algo types
    • Backend Knowledge
    • Burnout
    • consultancy
    • dev-level
    • Enterprise Developer
    • how-to-get-in-tech-from-other-job
    • how-to-get-into-junior-dev-position
    • induction
    • Interview
    • junior
    • mid
    • New Job
    • paths
    • Principle/staff Engineer
    • Requirements for job
    • Senior Dev capabilities
    • learning
      • automating-beginner
      • company1
        • analyst-progression
        • core-eng-progression
        • dev-progression
        • perf-eng-progression
        • soft-deliv-progression
    • mentoring
      • mentor-resources
    • recruitment
      • questions
      • Spotting posers
  • Computer Science
    • boolean-algebra
    • Compiler
    • Finite State Machine
    • Hashing
    • Algorithms
      • Breadth Firth Search
      • complexity
      • Depth First Search
      • efficiency
      • Sliding Window
      • sorting
    • data-structures
      • AVL Trees
      • data-structures
      • Linked List
    • machines
      • Intel Machine
      • Turing Machine
      • von neumann machine
      • Zeus Machine
  • devops
    • The 5 Ideals
    • microservice
    • Artifact repository
    • Bugs and Fixes
    • Build police
    • cloud-servers
    • Deployments
    • Environments
    • GitOps
    • handling-releases
    • infrastructure-as-code
    • System Migrations
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    • On Premises Hosting
    • Properties/configuration
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    • Release
    • Roll Outs
    • serverless
    • Serverless
    • Cloud Services
    • Versioning
    • AWS
      • deploy-docker-esc
      • cloud-practitiioner-essentials-notes
        • Module 1 - Intro to AWS
        • Module 2 Compute in the cloud
        • Module 3 Global Infrastructure and Reliability
        • Module 4 Networking
        • Module 5 Storage and Databases
        • Security
        • 7 Monitoring and Aanlytics
        • 8 Pricing and Support
        • 9 Migration and Innovation
      • developer-associate
        • AWS Elastic Beanstalk
    • build-tools
      • Managing dependecies
      • Apache ANT
      • Gradle
        • Custom Plugins
        • local-jars
      • Project Management - maven
        • Archtypes
        • Build Lifecycles
        • Customising build lifecycle
        • Dependencies
        • Directory layout
        • jar-files
        • one-to-one
        • Modules
        • Phases
        • Maven Plugins
        • POM
        • profiles
        • setup
        • Starting a maven project
        • wrapper
    • CI/CD
      • Continuous Delivery
      • zookeeper
      • Continuous Integration (CI)
      • github-actions
      • Pipeline
      • Teamcity
    • Cloud computing
      • Overview
      • Service Models
      • Cloud Services
    • containers
      • Best Practices
      • Docker
    • Infrastructure
      • IT Infrastructure Model
      • Non functional Attributes (Quality Attributes)
        • Infrastructure Availability
        • Performance
        • Secruity
    • monitoring
      • Alerting
      • Monitoring & Metrics
      • Metrics
      • Ready pages
      • Splunk
      • Status pages
      • notes-devops-talk
      • logging
        • logging
        • issues
        • Logging
        • Logging
    • Service mesh
      • Service Discovery
      • Istio
    • Terraform
    • container-management
      • Kubernetes
        • commands-glossary
        • OLTP
        • config-maps
        • Links
        • ingress
        • SDP
        • minikube
        • filter
        • indexes
        • sidecar
        • continuous-deployment
  • General Paradigms
    • CAP theorem
    • designing data-intensive applications summary
    • a-philosophy-of-software-design-notes
    • Aspect oriented Programming (AOP)
    • Best Practice
    • Cargo Cult
    • Clean Code
    • Coding reflections
    • Cognitive Complexity
    • Complexity
    • Conventions
    • Design discussions
    • Design
    • Error Handling Checklist
    • Exceptions
    • Feature Flags/toggle
    • Functional requirements
    • Last Responsible Moment
    • Lock In
    • Named Arguments
    • Naming
    • Performance Fallacy
    • Quality
    • Redesign of a system
    • Resuse vs Decoupling
    • Rules for software designs
    • Sad Paths
    • Scaling Webservices
    • Scientific Method
    • stream-processing
    • Upstream and Downstream
    • Patterns
      • Client-SDK-Pattern
      • ORM
      • Api gateway
      • Business Rules Engine
      • cache
      • Composition Root
      • Dependency Injection Containers
      • Dependency Injections
      • Double Dispatch
      • Exception Handling
      • Gateway pattern
      • Humble Object
      • Inheritance for reuse
      • Null Object Pattern
      • Object Mother
      • Patterns
      • Collection pipeline pattern
      • Service Locator
      • Setter constructor
      • Static factory method
      • Step Builder Pattern
      • telescopic constructors
      • Toggles
      • API
        • Aims of API designs
        • Avoid Checked Exceptions
        • Avoid returning nulls
        • Be defensive with your data
        • convience-methods
        • Fluent Interfaces
        • Loan Pattern
        • prefer-enums-to-boolean-returns
        • return-meaningful-types
        • Small intefaces
        • Support Lambdas
        • Weakest type
      • Gang of Four
        • Builder
        • Factory Pattern
        • Strategy Pattern
        • Template
        • abstract Factory
        • Adapter
        • Bridge Pattern
        • Chain of responsibility
        • Command Pattern
        • Composite Design Pattern
        • Decorator Pattern
        • Facade Pattern
        • Flyweight pattern
        • Guard Clause
        • Interpreter
        • html
        • Mediator Pattern
        • Memento Pattern
        • Observer
        • Prototype
        • Proxy
        • Singleton
        • State Pattern
        • Visitor Pattern
    • Architecture
      • Entity Component System
      • Integration Operation Segregation Principle
      • Adaptable Architecture
      • Architecture
      • C4 Modelling
      • cell-based
      • Clean/Hexagonal Architecture
      • Codifying architecture
      • Correct By configuration
      • Cost Base Architecture
      • Data Oriented Design
      • deliberate
      • Domain oriented DOMA
      • Event Driven Architecture
      • Evolutionary Architecture
      • examples
      • Feature Architecture
      • Framework and Libraries
      • functional-core-imperative-shell
      • Layered Architecture
      • Micro services
      • monoliths-to-services
      • Multi tiered Architecture
      • Multi tenant application
      • Resilient Architecture
      • stage event driven architecture (SEDA)
      • links spring rest app
      • Tomato Architecture
      • Tooling
      • Types of architecture
      • checklist
        • Checklist for new project
        • Back end Architecture Checklist
        • Front end Architecture Checklist
        • Mobile Architecture Checklist
      • Cloud Patterns
        • Command and Query Responsibility Segregation (CQRS)
        • Event Sourcing & CQRS
        • Asynchronous Request and Reply
        • Circuit Breaker
        • Retry
        • Sidecar
        • Strangler pattern
      • Domain driven design
        • value & entity
      • Microservices
        • Alternatives to choosing microservices first when scaling
        • Consistency in distributed systems
        • 12 Factor applications
      • Modularity
        • Module monolith vs Microservices
        • Spring Moduilth
      • Architecture Patterns
        • Hexagonal architecture
        • Inverting dependencies
        • Layering & Dependency Inversion Principle
        • Mappings
        • Vertical Slice architecture
        • Web Client Server
        • domain
          • Business and Data Layers Separation
          • DTO
          • Domain Model Pattern
          • Domain Object
          • Transaction Script/ Use Case pattern
        • Enterprise Patterns
          • Concurrency
          • Distribution strategies
          • Domain layer patterns
          • Layering/organisation of code
          • Mapping to datasource
          • Session State
        • Usecases
          • Use case return types
      • Serverless
        • Knative
    • Design architecture aims
      • back of envelope
      • Design ideas
      • Design mistakes
      • high-volume-design
      • ISO Quality Attributes
      • Non functional requirements
      • “Designing for Performance” by Martin Thompson
      • High Performance
      • Qaulity Attributes
        • Availability
        • System Availability
        • Fault Tolerance
        • interoperability
        • Latency
        • Maintability
        • Modifiability
        • Performance
        • Readability
        • Reliability
        • Scalability vs performance
        • Scalability
        • Scaling
        • statelessness
        • Testability
        • Throughput
      • System Design
      • web-scalability-distributed-arch
        • scalable-and-distributed-web-architecture
    • README
      • Conflict-free Replicated Data Type
      • Fallacies
      • Load balancing
      • Rate Limiting
      • Transactions
    • Patterns of Enterprise Application Architecture
      • Repository Pattern
      • Rules Engines
      • scatter-gather
      • Specification Design Pattern
      • Table Driven Development
      • Workflow Design Patterns
        • Triggers
    • Principles
      • Do It Or Get Bitten In The End
      • Dont Repeat Yourself
      • Habitability
      • Keep it simple
      • Responsibility Driven Design
      • Ya Ain’t Gonna Need It
      • Conceptual Overhead
      • CUPID
      • Reuse existing interfaces
      • Facts and Fallacies
      • locality of behaviour
      • Separation of Concerns
      • Simplicity
      • SLAP principle
      • Step down rule
      • Unix Philosophy
      • Wrong abstractions
      • SOLID
        • 1. Single Responsibility Principle
        • 2. Open Close Principle
        • 3. Liskov Substitution Principle
        • 4. Interface Segregation Principle
        • 5. Dependency Inversion Principle
        • GRASP (General Responsibility Assignment Software Principles)
        • Solid for packages
          • jobs
          • CCP
          • CRP
          • REP
          • egress
          • gossip-protocol
        • STUPID
    • programming-types
      • Coding to Contract/Interface
      • Links
      • Declarative vs Imperative Programming Languages
      • defensive-programming
      • Design by contract
      • Domain Specific Languages (DSL)
      • Event Driven
      • file-transfers
      • Logical Programming
      • Mutability
      • Self Healing
      • Simplicity
      • Type Driven Design
      • Value objects
      • Aspect Oriented Programming
      • Concurrent and Parallel Programming
        • Actor Model
        • Asynchronous and Synchronous Programming
        • Batch processing
        • Concurrency Models
        • SAP
        • Multithreading
        • Non Blocking IO
        • Optimistic vs Pessimistic Concurrency
        • Thread per connection or request model
        • Actor
        • aysnchronous-tasks
          • Computational Graphs
          • Divide and conquer
          • Future
          • Thread Pool
        • barriers
          • Barriers
          • Race conditions
        • design
          • agglomeration
          • Communication
          • Mapping
          • Partitioning
        • Liveness
          • Abandoned Lock
          • Deadlocks
          • Livelock
          • Starvation
        • locks
          • Read write lock
          • Reentrant lock
          • Try Lock
        • Mutual Exclusion
          • Data Races
          • Mutual Exclusion AKA Locks
        • performance
          • Amdahl's Law
          • Latency, throughput & speed
          • Measure Speed up
        • synchronization
          • Condition variable
          • producer consumer pattern
          • Semaphore
        • Threads and processes
          • Concurrent and parallel programming
          • Daemon Thread
          • Execution Scheduling
          • sequential-parallel
          • Thread Lifecycle
          • threads-and-processes
      • Functional Programming
        • Currying
        • design-patterns-to-func
        • imperative-programming
        • First class functions
        • Functional Looping
        • Higher Order Functions
        • Immutability
        • Issues with functional Programming
        • Lambda calculus
        • Lazy & Eager
        • map
        • Monad
        • Railway Programming
        • Recursion
        • Reduce
        • referential-transparacy
        • Referential transparency
        • Supplier
      • oop-design
        • Issues with object oriented code
        • Aggregation
        • Anti Patterns
        • Association
        • class-and-objects
        • Composition
        • general-laws-of-programming
        • general-notes
        • Getters and Setters
        • Inside out programming
        • Inversion of control
        • oop-design
        • Other principles
        • Outside in programming
        • Readability
        • Why OO is bad
        • README
          • abstraction
          • encapsulation
          • inheritance
          • Polymorphism
        • clean-code
          • Code Smells
          • Comments
          • Naming
          • CLEAN design
            • code is assertive
            • Cohesion
            • Connascence
            • Coupling
            • Encapsulation
            • Loose Coupling
            • Nonredundant code
      • Reactive Programming
        • reactive-programming
    • Projects and Software types
      • Applicatoin Development
      • Buying or creating software
      • Console Applications
      • Embedded Software development
      • Enterprise
      • Framework Development
      • Games
      • Library development
      • Rewriting
      • White Label Apps
    • State Machines
      • Spring State Machine
  • Other
    • 10x devs
    • Aim of software
    • Choosing Technologies
    • Coding faster
    • Component ownership
    • developer-pain-points
    • Developer Types
    • Effective Software design
    • Full Stack Developer
    • Good coder
    • Issues with Software Engineering and Engineers
    • Learning
    • Logic
    • Role
    • Software Actions
    • Software craftmanship
    • Software Designed
    • Software Engineering
    • Software
    • article-summaries
      • General notes
      • Summary of The Grug Brained Developer A layman's guide to thinking like the self-aware smol brained
      • improve-backend-engineer
      • Optimising Api
      • Simple and Easy
    • README
  • Hardware
    • Cpu memory
    • Storage
  • Integration
    • GRPC
    • API
    • Apis and communications between apps
    • asynchronous and synchronous communications
    • Batch Processing
    • Communications between apps
    • Delivery
    • Distributed Computing
    • Entry point
    • Event Source
    • SDP
    • egress
    • Graphql
    • Idempotency
    • Libraries
    • Long Polling
    • Multiplexing & Demultiplexing
    • Publish Subscribe
    • Push
    • Request & Response
    • REST
    • Remote Method Invocation
    • Remote Procedure Calls
    • Server Sent Events
    • Short Polling
    • Sidecars
    • SOAP
    • Stateless and Stateful
    • Streams
    • Third Party Integrations
    • wdsl
    • Web Services
    • Webhooks
    • repository
    • Kafka
      • Kafka Streams
    • message-queues
      • ActiveMQ
      • Dead Letter Queue
      • JMS
      • Messaging
  • Languages
    • C
    • Choosing A Language
    • cobol
    • Composite Data Types
    • creating
    • Date time
    • Numbers
    • Pass by value vs Pass by reference
    • Primitive Data Types
    • REST anti-patterns
    • Rust
    • Scripting
    • Static typing
    • string
    • Task Oriented Language
    • assembly
    • Getting started
      • Functional Concepts
    • cpp
    • Java
      • Code style
      • Garbage Collection
      • Intellij Debugging
      • Artifacts, Jars
      • Java internals
      • Java resources
      • Java versions
      • JShell
      • Libraries
      • opinionated-guide
      • Starting java
      • Java Tools
      • Why use java
      • Advanced Java
        • Annotations
        • API
        • Database and java
        • Debugging Performance
        • Files IO
        • Finalize
        • JDBC
        • jni
        • Libraries
        • Logging
        • SAP
        • Memory Management
        • Modules
        • OTher
        • Packaging Application
        • Pattern matching
        • performance
        • Properties
        • Reference
        • reflection
        • Scaling
        • Scheduling
        • secruity
        • Serilization
        • Time in Java
        • validation
        • Vector
        • Concurrency and Multithreaading
          • Akka
          • ExecutorCompletionService
          • Asynchronous Programming
          • Concurrency and Threads
          • CountDownLatch
          • Conccurrent Data Structures
          • Executor Service
          • Futures
          • reactive
          • Semaphore
          • structured concurrency
          • Threadlocal
          • Threads
          • Virtual Threads
          • Mutual Exclusion
            • Atomic
            • Synchronized
            • Thread safe class
            • Threads
        • debug
          • heap-dumps
          • thread-dumps
        • functional
          • Collectors
          • Exception Handling
          • Flatmap
          • Functional Programming
          • Generators
          • Immutability
          • issues
          • Optional
          • Parallel Streams
          • Reduce
        • networks
          • HTTP client
          • servlet-webcontainers
          • sockets
          • ssl-tls-https
      • Basics of java
        • compilation
        • computation
        • Conditonal/Flow control
        • Excuting code
        • Instructions
        • Looping/Iterating
        • memory-types-variables
        • methods
        • Printing to screen/debugging
        • Setup the system
        • Data structures
          • Arrays
          • Arayslist/list
          • Map
      • Effective Java notes
        • Creating and Destroying Objects
        • Methods Common to All Objects
        • best-practice-api
        • Classes and Interfaces
        • Enums and Annotations
        • Generics
      • framework
        • aop
        • bad
        • Dagger
        • Databases
        • Lombok
        • Mapstruct
        • netty
        • resliance4j
        • RxJava
        • Vert.x
        • Spring
          • Spring Data Repositories
          • actuator
          • cloud-native
          • H2 Db in Spring
          • Initializrs
          • JDBC Template
          • Java Persistence API (JPA)
          • kotlin
          • Pitfalls and advice
          • PRoxies
          • Reactive
          • spring security
          • spring-aop
          • Spring Boot
          • spring-jdbc
          • Spring MVC
          • Spring Testing
          • Testing
          • Transaction
          • patterns
            • Component Scan Patterns
            • Concurrency
            • Decorator Pattern in Spring
        • Micronaut
          • DI
        • Quarkus
          • database
          • Links
      • Intermediate level java
        • String Class
        • Assertions
        • Casting
        • Clonable
        • Command line arguments
        • Common Libraries/classes
        • Comparators
        • Where to store them?
        • Shallow and Deep Copy
        • Date and Time
        • Enums
        • Equals and Hashcode
        • Equals and hashcode
        • Exceptions
        • Final
        • Finally
        • Generics
        • incrementors
        • Null
        • packages and imports
        • Random numbers
        • Regex
        • Static
        • toString()
        • OOP
          • Accessors
          • Classes
          • Object Oriented Programming
          • Constructors
          • Fields/state
          • Inheritence
          • Interfaces
          • Methods/behaviour
          • Nested Classes
          • Objects
          • Static VS Instance
          • Whether to use a dependency or static method?
        • Other Collections
          • Other Collections
          • Arraylist vs Linkedlist
          • LinkedHashMap
          • Linked List
          • Priority queue
          • Sequenced Collections
          • Set
          • Shallow vs Deep Copy
          • Time Complexity of Collections
          • What Collection To use?
    • kotlin
      • Domain Specific Language
      • learning
      • Libraries
      • Personal Roadmap
      • Links
    • Nodejs
      • Performance
  • Management & Workflow
    • Agile
    • Take Breaks
    • # Communication
    • Engineering Daybook
    • Estimates
    • Feedback Loops
    • Little's law
    • Managing Others
    • poser.
    • Presentations
    • self-improvement
    • software-teams
    • Task List
    • trade-off
    • Types of devs
    • Type of work
    • Waterfall Methodology
    • coding-process
      • Bugs
      • Code Review
      • Code Reviews
      • Documentation
      • Done
      • Handover
      • Mob Programming
      • Navigate codebase
      • Pair Programming
      • Pull Requests
      • How to do a story
      • Story to code
      • Trunk based development
      • Xtreme Programming (XP)
      • debugging
        • 9 Rules of Thumb of Dubugging
        • Debugging
        • using-debugger
      • Legacy code
        • Legacy crisis
        • Working with legacy code
    • Managing work
      • Theory of constraints
      • Distributed Teams
      • estimations
      • Improving team's output
      • Kanban
      • Kick offs
      • Retrospectives
      • Scrum
      • Sign offs
      • Stand ups
      • Time bombs
      • Project management triangle
    • Notion
    • recruitment
      • In Person Test
      • Interviews
      • Unattended test
  • Networks
    • Content Delivery Network - CDN
    • DNS
    • cache control
    • Cookies and Sessions
    • Docker Networking
    • Duplex
    • Etags
    • HTTP Cache
    • HTTP - Hyper Text Transfer Protocol
    • HTTP/2
    • Http 3
    • Internet & Web
    • iptables
    • Keep alive
    • Leader Election
    • Load balancer
    • long-polling
    • Network Access Control
    • Network Address Translation (NAT)
    • Network Layers
    • Nginx
    • OSI network model
    • Persistent Connection
    • Polling
    • Proxy
    • Quic
    • reverse-proxy
    • servers
    • Server sent events (SSE)
    • SSH
    • Streaming
    • Timeouts
    • Url Encoding
    • Web sockets
    • WebRTC (Web Real-Time Communication)
    • Wireshark
    • tcp/ip
      • Congestion
      • IP - Internet Protocol
      • TCP - Transmission Control Protocol
  • Operating Systems
    • Cloud Computing
    • Distributed File Systems
    • Distributed Shared Memory
    • Input/Output Management
    • Inter-Process Communication
    • Threads and Concurrency
    • Virtualization
    • Searching using CLI
    • Bash and scripting
    • Booting of linux
    • makefile
    • Memory Management
    • Processes and Process Management
    • Scheduling
    • Scripting
    • Links
    • Ubuntu
    • Unix File System
    • User groups
    • Linux
  • Other Topics
    • Finite state machine
    • Floating point
    • Googling
    • Setup
    • Unicode
    • Machine Learning
      • Artificial Intelligence
      • Jupyter Notebook
    • Blockchain
    • Front End
      • Single Page App
      • cqrs
      • css
      • Debounce
      • Dom, Virtual Dom
      • ADP
      • htmx
      • Island Architecture
      • Why use?
      • Java and front end tech
      • mermaidjs
      • Next JS
      • javascript
        • Debounce
        • design
        • Event loop
        • testing
        • Typescript
        • react
          • Design
          • learning
          • performance
          • React JS
          • testing
      • performance
      • Static website
    • jobs
      • Tooling
      • bash text editor - vim
      • VS code
      • scaling
        • AI Assistant
        • Debugging
        • General features and tips and tricks
        • IDE - Intellij
        • Plugins
        • Spring usage
  • persistance
    • ACID - Atomicity, Consistency, Isolation, Durability
    • BASE - Basic Availability, Soft state, Eventual Consistency
    • Buffer
    • Connection pooling
    • service
    • Database Migrations - flywaydb
    • Databases
    • Eventual Consistency
    • GraphQL
    • IDs
    • indexing
    • MongoDB
    • Normalisation
    • ORacle sql
    • Partitioning
    • patterns
    • PL SQL
    • Replication and Sharding
    • Repository pattern
    • Sharding
    • Snapshot
    • Strong Consistency
    • links
    • Files
      • Areas to think of
    • hibernate
      • ORM-hibernate
    • Indexes
      • Elastisearch
    • relationships
      • many-to-many
      • SDP
      • serverless
      • x-to-x-relationships
    • sql
      • Group by
      • indexes
      • Joins
      • Common mistakes
      • operators
      • performance
    • types
      • maven-commands-on-intellij
      • in-memory-database-h2
      • Key value database/store
      • Mongo DB
      • NoSQL Databases
      • Relational Database
      • Relational Vs Document Databases
  • Security
    • OAuth
    • API Keys
    • Certificates and JKS
    • Cluster Secruity
    • Communication Between Two Applications via TLS
    • Cookies & Sessions
    • CORS - Cross-Origin Resource Sharing
    • csrf
    • Encryption and Decryption
    • Endpoint Protection
    • JWT
    • language-specific
    • OpenID
    • OWASP
    • Secrets
    • Secruity
    • Servlet authentication and Authorization
    • vault
  • Testing, Maintainablity & Debugging
    • Service-virtualization and api mocking
    • a-test-bk
    • Build Monitor
    • Builds
    • Code coverage
    • consumer-driven contract testing
    • Fixity
    • Living Documentation
    • Mocks, Stubs & Doubles
    • patterns
    • Quality Engineering
    • Reading and working with legacy code
    • Reading
    • remote-debug-intellij
    • simulator
    • Technical Debt
    • Technical Waste
    • Test cases
    • Test Data Builders
    • Test Pyramids
    • Test Types
    • Testing Good Practice
    • Testing
    • What to prime
    • What to test
    • Debugging
      • Debugging in kubernetes or Docker
    • fixing
      • How to Deal with I/O Expense
      • How to Manage Memory
      • How to Optimize Loops
      • How to Fix Performance Problems
    • Legacy Code
      • Learning
      • Legacy code
      • techniques
    • libraries
      • assertj
      • Data Faker
      • Junit
      • mockito
      • Test Containers
      • Wiremock
      • Yatspec
    • Refactoring
      • Code Smells
      • refactoring-types
      • Refactoring
      • Technical Debt
      • pyramid-of-refactoring
        • Pyramid of Refactoring
    • Test first strategies
      • Acceptance Testing Driven Developement (ATDD)
      • Behaviour Driven Development/Design - BDD
      • Inside out
      • Outside in
      • Test driven development (TDD)
    • testing
      • Acceptance tests
      • How Much Testing is Enough?
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  • Definitions
  • Benefits
  • Information hiding
  • Encapsulation is not information hiding
  • Breaking encapsulation
  • Encapsulation and frameworks
  • Drawbacks

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Encapsulation

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Last updated 3 years ago

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  • Encapsulation is a programming language feature.

Definitions

  • Encapasulation is making something which is varying appear to the outside as if it is not varying.

  • Encapsulation allows us to tame the growing state and complexity

    • The idea that we can internalize the state, hide it from other components, and offer only a carefully designed API surface for any state mutation is core to the design and coding of complex information systems

  • Encapsulation means drawing a boundary around something. It means being able to talk about the inside and the outside of it

  • What can be encapsulated

    • Relationships

    • processes

    • varying behaviours

    • the number of steps

    • the order of steps in a process

    • hide a concept behind an abstraction/interface

    • hide the way you implement an algorithm behind a method signature

    • Wrap foreign code in your code via adapter/facade pattern

  • an object being strongly or weakly encapsulated depending on how much of its implementation is hidden.

  • done via, "program to an interface not an implementation"

  • What you don't know can't hurt you

    • Encapsulate by policy, reveal by need

    • Make everything private, then expose more ie package, protected or public, to expose later

  • Encapsulation allows you to check access to your own innards, and provide specific methods of performing such access

    • It does not specifically address leaking implementation details; although you can control access to that variable, you can no longer control the fact that the client knows your using an ArrayList, even if you later decide to use LinkedList.

  • Encapsulation is the grouping of related ideas into one unit, which can thereafter be referred to by a single name.

    • attributes that represents the state of an object and the methods that work on them are packaged into an object type.

    • Putting the responsibility for each object with the object itself where it belongs

  • The result of hiding a representation and implementation in an object...

  • Encapsulation is an OOP concept where object state(class fields) and it's behaviour(methods) is wrapped together. Java provides encapsulation using class.

  • Quality code occurs when it hides the implementation details form the rest of the world.

  • Not just making state or behaviour private

  • Aim to to hide the interface (what I am trying to accomplish) from the implementation (how I accomplish it)

  • Comes from designing *outside in and not inside out

    • Need both, to see the big picture

  • The domain model should be separate from implementation details as possible

  • We want to model things in the world we also want to model their limited perspective

  • All about delegating to other objects to do the work

  • Design patterns encapsulate something differently

  • Manages complexity, keep the caller out of the implementation details of the callee, makes it easier to change

    • If my tests are implementation dependent, I have encapsulation issues

Benefits

  • The more you can hide how you implement something, the more freedom you have to change the implementation later without affecting other parts of the code

  • Keeps code more modular and simpler to work with

  • What you can hide, you can change later without breaking other code that depends on it

  • Reduce ripple effect

  • if you dont know about something you can't couple to it.

    • Fewer dependencies make code easier to change

  • Prevent hard bugs to solve caused by inconsistent state

Information hiding

  • Information Hiding is a design principle

    • use interfaces rather than objects (other than at creation).

  • information hiding gives rise to the notions of encapsulation and abstraction.

  • every module in the [...] decomposition is characterized by its knowledge of a design decision which it hides from all others. Its interface or definition was chosen to reveal as little as possible about its inner workings.

    • some separate entity or module which has some responsibility that we need fulfilled, and we are not interested about how it is fulfilled. But the emphasis here is a bit more about hiding the details from other modules (or objects)

  • InformationHiding is the idea that a design decision should be hidden from the rest of the system to prevent unintended coupling

  • is hiding the fact that your using an ArrayList to implement your data structure. Although the client could still find out how your implementing it (Information Hiding Is Not Information Erasing), you're no longer responsible for supporting that implementation.

  • mechanism for restricting access to some of the object's components. Your above example is the case of Information Hiding if you make age private.

  • Information hiding is a great principle for enabling focus on a useful abstraction rather than a mass of detail, for sure. But it implies a choice to delve into details only when relevant, not ignorance of the details.

Encapsulation is not information hiding

  • Information Hiding should inform the way you encapsulate things, but of course it doesn't have to

  • encapsulation does need some degree of information hiding.

  • https://www.javaworld.com/article/2075271/core-java/encapsulation-is-not-information-hiding.html

  • http://web.archive.org/web/20000816234125/http://www.itmweb.com:80/essay550.htm

  • http://web.archive.org/web/20090505194203/http://homepage.mac.com/keithray/blog/2006/02/22/#EncapsulationHiding

  • http://wiki.c2.com/?EncapsulationIsNotInformationHiding

  • http://www.stefanoricciardi.com/2009/12/06/encapsulation-and-information-hiding/

Breaking encapsulation

  • Examples

    • Using setters

    • violating law of Demetar

    • using the details of impl of an object, rather than a cleaner interface

    • not using interface

    • non final fields

    • data structures that can be mutated despite reference to it

    • use of reflection

    • inheritance

    • patterns like visitor

    • Using the toString output, to get values of fields

Encapsulation and frameworks

  • Frameworks dont work well with immutability.

    • They need fields to be non final, or setters need to be created

  • use an anticorruption layer to protect and validate your internal state after those setter interactions

Drawbacks

  • you protect "mutable" state within the object with methods that receive messages and these public interface methods would protect data -- especially if you are working with multi-threaded applications

    • This allowed us to limit the scope of the code that had access to mutate the data.

    • this did not get rid of the problems with working with multi threaded applications, just reduced it to one area

    • The lack of good coding standards and frameworks, has led to code breaking encapsulation

    • Since the data is mutable and the functions and methods mutate the data and rely on the state which can change - testing the correctness of any algorithmic function is meaningless in the overall correctness of the object or the application.

    • To avoid the issues with mulit threading, we need to synchronize the data access in the object itself which is often not done perfectly.

  • The move to immutable data, means no changes to data/state in the class, thus encapsulation is just a grouping of functions in such classes

Encapsulation
Definitions
Benefits
Information hiding
Encapsulation is not information hiding
Breaking encapsulation
Encapsulation and frameworks