[JAVA] I participated in JJUG CCC 2019 Fall.

I participated in JJUG CCC 2019 Fall.

Participated in the event for the first time in half a year with Java! !!

Basic knowledge of object-oriented programming learned in Java

Presenter's material

--Object-oriented thinking can be applied to software development --Mr. Masuda's commitment to object-oriented programming --Modularity --Split the program by type (value type) --Make a module with a mold --Seaminess --Development method to eliminate the seams of a series of activities --Words I want you to take home --Type

Impressions

It was completely different from what I thought in advance, but it was quite interesting

13: 30-14: 15 Open! Domain Driven Design Door

Presenter's material (No)

Overview

What is Domain Driven Design? How good is it? How should I do it? (Around here was too fast to take notes at all)

Memo when I heard

--Motivation ――Why Domain Driven Design? --What is Non-Domain Driven Design? --Get lost in the code forest --Scattering related implementations

--Summary --Domain Driven Design is a practice for practicing what is commonplace

Impressions

It was interesting because there was a story that led to "basic knowledge of object-oriented programming learned in Java". There were many points that I couldn't keep up with because it was too fast.

14: 30-15: 15 Reintroduction to JUnit

Presenter's material

Note

――Why write test code --Because regression testing is possible --High reliability ――Do not leave personality --Confirm debug completion at runtime ――Debugging is fun ――Psychological damage occurs when humans point out mistakes. .. .. .. --Test tips --Write the test first --Implemented after confirming test failure --Implemented after guaranteeing failure --Give a descriptive test name --Write the test name in Japanese --All team members must be fluent in Japanese --Do not overwrite assertions ――Write in moderately organized units --Use assertAll as needed --Don't be too particular about coverage --Do not test proven code --No need to test getter and setter

Impressions

I felt that the first half was for beginners and the second half was important At present, it has not been developed for test first, so I felt that I wanted to improve it. I especially want to work on UI testing.

16: 45-17: 30 An example of breaking away from the huge legacy system at Name.com, where the third year of new graduates faced

Presenter's material

Note

--What is a legacy system? --Behavior as intended --The internal code is complicated and difficult to maintain. --High maintenance cost --Problems of breaking away from legacy systems --There is no document about the specifications (specifications) --Some parts are complicated and difficult to correct (implementation) --Implemented in pure Java --Implementation that is difficult to understand --Define raw query --Solid setting information --Class responsibility is ambiguous --No unit test code (test)

Impressions

I often look at the in-house system, but it is often difficult to understand the implementation. I feel that there are many opportunities to fight legacy systems. (Repairs will be done soon ...) I will use it as a reference for how to fight! !!

Impressions of the entire event

I attended a lecture for beginners, but I often couldn't keep up with the amount of information. → I want you to reduce the amount of information, such as limiting the number of slides. I was surprised that the lunch was gorgeous → It was delicious. Thank you very much. I also wanted to hear about Gradle → The first step for those who fully understand Gradle to not understand anything I want to focus on listening to UI testing ← I'm interested now

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