☕️ Java BACKEND developers ☕️

𝗪𝗵𝗲𝗻 𝘁𝗼 𝘀𝗲𝗹𝗲𝗰𝘁 𝗗𝗲𝘀𝗶𝗴𝗻 𝗣𝗮𝘁𝘁𝗲𝗿𝗻𝐬?

Choosing the correct design pattern in software engineering is critical to practical problem-solving.
This post will try to simplify the process, helping you decide between patterns based on specific needs.
To select a pattern, we must first go through the problem identification. If the problem is related to:
🔸 Object Creation? → Creational Patterns
🔸 Object Assembly? → Structural Patterns
🔸 Object Interactions? → Behavioral Patterns
1. Singleton: Ensures only one instance exists.
2. Factory Method: Delegates object instantiation to subclasses.
3. Abstract Factory: Creates related object families without specifying their concrete classes.
4. Prototype: Clones objects for a prototypical instance.
5. Builder: Constructs complex objects step by step.
6. Adapter: Bridges incompatible interfaces.
7. Bridge: Separates abstraction from implementation.
8. Composite: Treats single and composite objects uniformly.
9. Decorator: Adds behaviors to objects dynamically.
10. Facade: Simplifies complex system interfaces.
11. Flyweight: Shares objects to reduce memory.
12. Proxy: Controls object access.
13. Observer: Notifies changes to multiple objects.
14. Strategy: Encapsulates interchangeable algorithms.
15. Command: Encapsulates a request as an object.
16. State: Changes object behavior with internal state.
17. Visitor: Adds operations to object structures without modifying them.
18. Memento: Captures and restores object states externally.
19. Iterator: Sequentially accesses elements of a collection.
20. Mediator: Centralizes complex communications.
21. Chain of Responsibility: Passes requests along a chain of handlers.
22. Template Method: Defines the skeleton of an algorithm.

#Savol : Javada casting nima?

#Javob : Javada casting bitta ma'lumot turini boshqasiga o'zgartirish jarayonidir. Kengaytiruvchi (widening) va toraytiruvchi (narrowing) casting mavjud. Kengaytiruvchi casting avtomatik ravishda amalga oshiriladi, toraytiruvchi casting esa qo'lda bajariladi.

Kichik turdan kattaroq turga avtomatik casting:

byte → short → int → long → float → double

Katta turdan kichik turga casting quyidagi ko'rinishda bo'ladi:

double → float → long → int → short → byte

JIT (Just-In-Time) kompilatori

Java Virtual Machine (JVM) tomonidan ishlatiladigan texnikadir. JIT kompilyatori Java dasturlarining ish vaqtida ishlashi samaradorligini oshirish uchun mas'uldir.

Oddiy qilib aytganda, Java kodini avval bayt kodga (Java dasturi yozilganidan so'ng kompilyator tomonidan yaratiladigan vositaviy kod) kompilyatsiya qiladi. Bayt kod dastlab JVM tomonidan interpretatsiya qilinadi, ya'ni buyruq bajarilganda qadam-baqadam amalga oshiriladi. JIT kompilyatori esa, interpretatsiya jarayonini optimallashtiradi va ishlash vaqtida ko'p martalab ishlatiladigan bayt kod qismlarini mashina kodiga (native code) aylantiradi. Bu mashina kodi to'g'ridan-to'g'ri protsessor tomonidan bajarilishi mumkin, bu esa tezlikni sezilarli darajada oshiradi.

JIT kompilyatori quyidagi afzalliklarni beradi:

Yuqori tezlik: Bayt kodni native code ga o'girib , dasturlarni ko'proq samarali bajaradi.

Ish vaqtida optimallashtirish: JIT kodni kompilyatsiya qilishda uni ishlash vaqtida qo'shimcha tahlil qilib, optimallashtirilgan kod yaratadi.