📂 Today I Learned

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algorithm

• Binary Search
• Brute Force Search
• DFS BFS
• Dijkstra
• Dynamic Programming
• Floyd-Warshall
• Greedy
• Sort

data-structure

• Array, List, LinkedList
• Graph vs Tree
• Hash, Map, HashMap
• Heap
• Stack Queue

database

• Database Lock
• Execution Plan
• Index
• Join Algorithm
• MySQL 사용자 권한부여
• Normalization
• Row Oriented vs Column Oriented
• Transaction
• Transaction Isolation Level
• VARCHAR의 길이제한

design-pattern

• Abstract Factory Pattern
• Adapter Pattern
• Bridge Pattern
• Builder Pattern
• Chain of Responsibility Pattern
• Class Diagram
• Command Pattern
• Composite Pattern
• Decorator Pattern
• Facade Pattern
• Factory Method Pattern
• Flyweight Pattern
• Iterator Pattern
• Mediator Pattern
• Memento Pattern
• Observer Pattern
• Prototype Pattern
• Proxy Pattern
• SOLID
• Singleton Pattern
• State Pattern
• Strategy Pattern
• Template Method Pattern
• UML
• 객체지향 패러다임
• 결합도와 응집도

docker

• Docker
• Docker Network
• Volume vs Bind Mount

etc

• Gradle
• Gradle daemon
• block-vs-non-block-sync-vs-async

git

• Git Merge vs Git Rebase
• Interactive Rebase
• 자주 사용하는 Git 명령어 모음

java

• Annotation
• Call method by reflection
• Exception Handling
• Generic
• Generic wildcard를 이용한 extends super 사용 시 주의할 점
• Graceful shutdown
• JVM
• Java21 Improvement Record, Switch
• Java21 Sequenced Collections
• Java21 Virtual Thread
• Java 코드의 실행 과정
• Lambda Expression
• Object Class
• Optional
• Primitive Type & Reference Type
• ReentrantLock
• Reflection
• Serialize And Deserialize
• Statement vs Prepared Statement
• Stream
• String, StringBuilder, StringBuffer
• Thread-safe Collection
• Tiles
• Type Casting
• Why is sort() a static method
• map vs flatMap
• tomcat architecture
• 추상클래스와 인터페이스의 차이

effective-java

• Item 1. static factory method
• Item 10. override equals
• Item 11. override hashCode
• Item 12. override toString
• Item 13. override clone
• Item 14. implement comparable
• Item 15. field access modifier
• Item 16. get method
• Item 17. minimize mutability
• Item 18. use composition instead extend
• Item 19. prepare docs if extend
• Item 2. builder pattern
• Item 20. abstract class vs interface
• Item 21. interface default method
• Item 22. use interface only type
• Item 23. use class hierarchy
• Item 24. member class
• Item 25. only one top level class
• Item 26. don't use raw type
• Item 27. remove unchecked warning
• Item 28. replace array with list
• Item 29. use generic type
• Item 3. singleton
• Item 30. use generic method
• Item 31. use wildcard type
• Item 32. varargs with generic
• Item 33. type safe heterogeneous container
• Item 34. enum type
• Item 35. don't use enum ordinal
• Item 36. EnumSet
• Item 37. EnumMap
• Item 38. use interface for extend enum
• Item 39. annotation
• Item 4. private constructor
• Item 40. @Override
• Item 41. marker interface
• Item 42. replace anonymous class with lambda
• Item 43. method reference
• Item 44. default functional interface
• Item 45. stream
• Item 46. collector
• Item 47. return collection
• Item 48. stream parallel
• Item 49. validate parameter
• Item 5. dependency injection
• Item 50. make defensive copies
• Item 51. design method signatures carefully
• Item 52. use overloading judiciously
• Item 53. varargs
• Item 54. return array or collections instead of null
• Item 54. use optional judiciously
• Item 55. return optional judiciously
• Item 56. write javadoc
• Item 57. minimize scope of local variable
• Item 58. for-each
• Item 59. use library
• Item 6. reuse instance
• Item 60. if you need accurate answer, avoid float and double
• Item 61. use primitive type instead of wrapper
• Item 62. avoid string
• Item 63. avoid concat string
• Item 64. refer interface
• Item 65. reflection
• Item 66. avoid using native method
• Item 67. optimize judiciously
• Item 68. naming convention
• Item 69. use exceptions only for exceptional conditions
• Item 7. eliminate unused reference
• Item 70. checked, unchecked exception
• Item 71. avoid using unnecessary checked exceptions
• Item 72. use default exception
• Item 73. translate low level exception
• Item 74. documentation exceptions thrown by method
• Item 75. include failure capture information in detail messages
• Item 76. strive for failure atomicity
• Item 77. don't ignore exceptions
• Item 78. synchronize access to shared mutable data
• Item 79. avoid excessive synchronization
• Item 8. avoid using finalizer, cleaner
• Item 80. prefer executors, tasks, and stream to threads
• Item 81. prefer concurrency utilities to wait and notify
• Item 82. document thread safety
• Item 83. use lazy initialization judiciously
• Item 84. don't depend on the thread scheduler
• Item 85. prefer alternatives to java serialization
• Item 86. implement serializable with great caution
• Item 87. consider using a custom serialized form
• Item 88. write readObject methods defensively
• Item 89. for instance control, prefer enum types to readResolve
• Item 9. try-with-resources
• Item 90. consider serialization proxies instead of serialized instances

jpa

• @DynamicInsert, @DynamicUpdate
• Entity Manager
• Find by EntityManager vs JPQL select query
• JPA
• JPA Cascade
• JPA Entity Equality
• JPA Entity LifeCycle
• JPA Entity Lifecycle Event
• JPA bulk update
• Lock
• Open Session In View
• save() vs saveAndFlush()

junit

• Argument Matcher, Argument Captor
• JUnit 4의 @Test 메서드는 public 이어야 했는데, JUnit 5 부터는 public이 아니어도 되는 이유

querydsl

• Projection
• QueryDSL Setup
• [우이콘2020] 수십억건에서 Querydsl 사용하기

kubernetes

• 쿠버네티스를 왜 쓰는가

linux

• Linux의 Permission
• kill

network

• CIDR
• Forward Proxy vs Reverse Proxy
• Forward vs Redirect
• HTTP의 진화와 버전별 특징
• OSI 7 Layer
• SSL, TLS
• Subnet
• 그림으로 배우는 http & network basic

operating-system

• Block vs Non-block, Sync vs Async

python

• Python의 재귀제한

server

• CI&CD
• Cache
• Cloud Service
• 정적 서버와 동적 서버

spring

• @Async
• @Configuration
• @RequestParam @RequestBody @ModelAttribute
• AOP
• Autowired
• Bean Scope
• Bean could not be injected because it is a JDK dynamic proxy
• Component Scan
• Component vs Bean
• Configuration 분리
• DI
• Embedded tomcat
• Filter, Interceptor, Spring AOP
• IoC Container
• Nested Class의 Bean 등록
• Profile
• Properties
• Servlet container vs Spring container
• Spring Bean Life Cycle
• Spring Event
• Spring vs SpringBoot
• Thymeleaf

jpa

• Dirty Checking
• JPA Fetch 전략
• JPA N+1 Problem

spring-boot

• Spring Web Layer
• spring-boot

spring-mvc

• Argument Resolver
• Filter
• Filter vs OncePerRequestFilter
• Interceptor
• RestController
• Validator
• exception-handling
• spring-mvc

spring-security

• Spring Security

testing

• Test Double
• White Box, Black Box

web

• API
• Browser Caching
• CORS
• HTTP Header
• HTTP와 HTTPS
• OAuth
• PRG Pattern
• Query Parameter & Path Variable
• REST
• Status Code
• WebSocket
• application octet stream
• cookie-session
• jwt
• multipart form data

images

• jwt-flow