⭐️ Layered Architecture Hexagonal Architecture Unit test 🆚 Integration test IoC, DI, AOP ORM, paradigm, Hibernate JPA ✅ Layered Architecutre in Spring ❓ why use layered architec...

✅ TDD red blue green 🔴 first create the test code //test code @DisplayName("Calculate the total price of beverages in order") @Test void getTotalPrice() { //give...

✅ / root directory: origin of the tree root user are not the same! ✅ Level 0 / means root, origin of the tree kernel root directory all mean the same ✅ Level 1 all have ...

✅ Installation on RM ✅ Installation on VM ☑️ Suggestion 1 Internal harddisk in order to avoid slow reading/writing access to USB ☑️ Suggestion 2 The iso for the Ubuntu in the V...

✅ Installation every release have same hardware requirements 🆚 flavors require different hardware requirements If you do not have the hardware requirements, change the flavor⭕️, not the rel...

✅ Where to download should be done from canonical > ubuntu canonical: company that created ubuntu ✅ Two types of downloads 1️⃣ Desktop for your own computer 2️⃣ Server ...

👍🏻 Ubuntu good performance flexible ✅ Releases lanzamiento numbers that follow the Ubuntu... ✔️ Version: Lubuntu 18.04 4 LTS distro: ubuntu flavor: LXQE or LXQT light for RA...

Distro 🆚 Flavor ✔️ Distro: Type of linux(👀 Debian, Ubuntu, Redhat…) ✔️ Flavor: Graphical aspect of the distro desktop Environment of the Distro also called DE 👀 There can be sev...

✅ Junit framework to help testing assertEquals ✅ AssertJ library with APIs to help testing assertThat().isEqualTo() assertThat().hasSize() assertThat().isEmpty() Manual Testing ...

🛠️ When to use singleton when only one instance should exist 👀 settings of an application ✅ How to create singleton should not use new ❌ create method getInstance() ✔️ Setti...