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Spring Batch of Death: The desperate terror of 3 AM is finally over.

"Let's master Spring Batch once and for all. Putting an end to the dark ages of batch code.💀"

(4.9) 86 reviews

1,787 learners

Level Basic

Course period Unlimited

Java
Java
Spring
Spring
Spring Boot
Spring Boot
Spring Batch
Spring Batch
backend
backend
Java
Java
Spring
Spring
Spring Boot
Spring Boot
Spring Batch
Spring Batch
backend
backend

Reviews from Early Learners

Reviews from Early Learners

4.9

5.0

기훈

62% enrolled

Kilgu-hyung! I'd planned to leave a review after finishing the course, but I got so emotional watching the lectures that I'm writing it now. As Kilgu-hyung said early in the lecture, studying with text is truly difficult, but it definitely seems to stick in your mind more. Thanks to Kilgu-hyung's writing, it's great to learn so enjoyably and without difficulty. Thank you for such an incredibly cost-effective lecture, and I look forward to your future courses!

4.0

김주현

100% enrolled

/** @param Date - 251012 @return String - After completing the course, updating course review */ First of all, thank you so much for this incredibly incredibly incredibly incredibly enriching lecture. I imagine it must have been really really hard work to create these course materials. I express my deep respect. 💀💀💀 However, since the course materials were structured as situational dramas, it was fun but I felt the text structure was a bit lacking. I think if the text structure (major categories-subcategories-minor categories, paragraph divisions, etc.) were improved a bit more, this could become a lecture that could dominate the entire world. Or if there were at least a table of contents for each material, I think it would have been easier to follow along even with the current approach. That way, I wouldn't get distracted by the situational drama and could keep track of how far I was progressing in my learning. Actually, this is the first time I've ever left such a long course review on Inflearn. I've never even left a course review on God Young-han's lectures. I hope you understand that this review comes from deep deep respect. Thank you sincerely for creating such a great lecture. I'll salute and disappear. Kill. Goo. 🫡

5.0

blessthy

100% enrolled

Kilgu hyung... I watched it all the way to the end. Started with Kim**'s Spring Boot in mid-June, then hit Lee**'s TDD, and finally in mid-August I entered Kilgu hyung's Spring Batch course and completed it!!! I skipped the missions here and there because work was busy and my skills are still tiny as a bean, but now I've mastered how Spring Batch works... Now... I will definitely replace the batch processing server of our project that's always running dangerously on patches with Spring Batch someday... If I had known something like this existed, I would have built it with Spring Batch from the beginning, which is such a shame... But if it weren't for Kilgu hyung, I embarrassingly would have never known about Spring Batch forever... Thank you so much for creating the course!! And throughout the entire course, I was amazed by Kilgu hyung's sharp expertise and gave tons of thumbs up and praise!! Thank you~!

What you will gain after the course

  • 💀 Spring Batch's Chunk-oriented Processing Model and Tasklet-oriented Processing 💀

  • 💀 A Complete Understanding of ItemReader, ItemProcessor, and ItemWriter 💀

  • 💀 Implementing Failure Recovery and Retry Mechanisms (both Batch5 & Batch6 model) 💀

  • 💀 Lifecycle and Execution Context Management of Jobs and Steps 💀

  • 💀 Multi-threaded Step (both Batch5 & Batch6 model) 💀

  • 💀 Large-Scale Data Parallel Processing Using Partitioning 💀

  • 💀 SEDA Pattern using Local Chunking and Parallel Steps 💀

  • 💀Spring Batch 5 & (NEW)Spring Batch 6 💀

  • ⛔ I should stop here... There were so many that the system almost crashed. (Don't worry. I'll teach you everything) ⛔

LGTM(Looks Gone To Me)

KILL-9: "Warning: Reading this document without the audio sequence reduces learning efficiency by 66%."


🚨 Warning: Critical Danger Detected 🚨

💀 Face reality 💀

🔥 What have you even been doing until now?🔥

⚠️ Spring Batch Execution Protocol Activated ⚠️


"For all developers suffering from batch jobs

The system executioner has stepped forward personally

The desperate terror of 3 AM is now over.💀"


Arm yourself with the latest and most accurate Spring Batch course. 💀


⛔ The Weapons You Will Acquire ⛔

Through this course, you will be equipped with the following lethal weapons, and

You will gain the power to dominate the system.

💀 Tasklet vs. Chunk Processing: Core Operations of the Batch System

Did you think the execution flow of batch code was a hidden black box? Ridiculous.

The two representative processing models of Spring Batch. We will dissect the concepts and internal operating principles of Tasklet-oriented processing and Chunk-oriented processing.

From simple one-off tasks like file organization or table TRUNCATE, to Chunk-oriented processing that reads, processes, and destructively writes millions of data records.

I will thoroughly dissect the internal operating principles of both methods, enabling you to intuitively judge which weapon is optimal for any given situation.


💀Data Execution Methods: ItemReader and ItemWriter

No longer suffer from large-scale data processing.

Whether it's a file system, RDBMS, or NoSQL, it extracts data (ItemReader) and injects it as desired (ItemWriter) without discrimination.

FlatFileItemReader, JsonItemReader,

JdbcCursorItemReader, JpaPagingItemReader

... Whether it's RDBMS or NoSQL, extract data (ItemReader) and inject it as desired (ItemWriter). FlatFileItemReader, JsonItemReader, JdbcCursorItemReader, JpaPagingItemReader. Dig into the internal workings of each implementation and master how to efficiently process large-scale data. Paging? Cursor? Your ignorance of which is suitable when...

Dig deep into the internal operating principles of each implementation and master how to efficiently execute large-scale data.

Paging? Cursor? Your ignorance of which is suitable when ends now.

💀 Job and Step Control: Seize Control of the Heart of the Batch System

Delve deep into the internal workings and lifecycles of Jobs and Steps.

By tracking the relationships between JobInstance, JobExecution, and StepExecution, as well as changes in their status (BatchStatus, ExitStatus), this provides the ability to clearly understand why a batch failed and from where it should be restarted (Restartability).

Look inside the JobRepository and directly control the metadata to transparently manage the batch execution flow that once felt like a black box. No longer be caught off guard by unexpected failures. Everything is placed under our control.

💀 Spring Batch Extensions (The image above is specifically for Batch 5. I chose it because it looks cooler.)

Too much data to process? Execution time taking too long? Don't worry.

For when basic weapons aren't enough, special equipment is ready to explode batch performance.

  • Parallelize tasks within a single step using multi-threading (Multi-threaded Step), and

  • For data that is too much to handle, break it down into smaller pieces using partitioning (Partitioning) and distribute them across multiple workers for processing.


Armed with this knowledge, your batches will no longer be brought to their knees by performance issues.

I have clearly summarized the true thread safety of Spring Batch more than anything else, so you can use it with confidence.

Now it's time for the batch system to be afraid of you.💀


💀 Spring Batch Additional Survival Skills (The image above is for Batch 5. I chose it because it looks cooler.)

  • Strategies for imprisoning and controlling failures using Skip/Retry policies.


  • Mastering state management and batch job stop/restart mechanisms using ItemStream.


  • How to design complex job flows with Spring Batch Flow.

  • How to monitor every moment of a batch with various Listeners

It will take time until you can use all the weapons perfectly.

But do not worry.

The combat experience I gained through my blood and sweat will accelerate your growth. 💀

💀 There is no paradise for those who run away 💀

💀To bring an end to this wretched chaos, I have stepped forward.💀

💀 Price Execution Manifesto 💀

Final Warning: It is time to choose

[EXECUTE: SYSTEM UPGRADE SEQUENCE]

# --- Preparing system for upgrade --- # Removing fear module... Done. $ rm -rf ./fear_of_batch_errors # Preparing skill directory... OK. $ mkdir -p /opt/advanced_batch_skills # Granting full access to tech stack... Permissions updated. $ sudo chmod 777 /opt/advanced_batch_skills # Injecting KILL-9 grade expertise... Root privileges acquired. Processing... $ sudo ./install-spring-batch-expertise [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100% Installation Complete. System Reboot Recommended for optimal performance.

FATAL WARNING

$ cat warning.txt ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠️ CAUTION ⚠️ [FATAL ERROR] Access Restriction Detected [PROCESS ID]: #KILL-9_WARNING_PROTOCOL [STATUS]: CRITICAL ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Those who attempt to access this lecture for fun, dazzled by its intense concept, leave immediately. This lecture shows no mercy to those with light curiosity attempting access without sudo privileges. I only want those who wish to walk the path of a true 'System Master'. I warn you clearly. Only those prepared to endure until the end of this pain should take this course. Your time is precious. Do not waste it. Only those with a genuine will to learn can handle the weight of this code. Only those who faithfully follow until the end of the lecture will become the true masters of Spring Batch. [ADDITIONAL NOTE] Even those with prior Spring Batch experience are welcome if a "will to follow diligently" is detected. $ ls -la /home/user/ | grep determination You will surely gain a lot. # The choice is yours. But the consequences are mine to execute.💀
$ sudo sound-off --tactical-report --system-status=spring-batch --volume=maximum --force

System Access Pre-Checklist

Practice Environment

MAC-based (JDK 21) environment. (Windows? Sigh... A Spring Batch server on Windows? You will only experience pain with Windows.)

JAVA 17, Spring Boot 3.4, Spring Batch 5.2 or
JAVA 21, Spring Boot 4.0.1, Spring Batch 6.0.1 environment.

That's right, Batch 5 & Batch 6. I teach both.

(Batch 6 release... whew...💀 I felt like my blood was drying up... Batch is eternal, but my time is finite.)

Learning Materials

"The era of video is over. It is now the era of text once again. 💀"


This is a text-based lecture. Wondering why? I've explained the reason for free at the beginning of the course, so

' The System Terminator's Learning Principles ' Read this.

Here, you will encounter my philosophy for true learning, not just a simple transfer of knowledge.

Recommended for
these people

Who is this course right for?

  • 💀 "Can you take charge of Spring Batch?" ... (Chilling laughter) To all the soldiers breaking into a cold sweat at this question 💀

  • 💀To all you soldiers who have only ever dug into Spring Web and are now too terrified to even look at Batch...💀

  • 💀To all you soldiers who have wiped out millions of rows of data by copy-pasting someone else's batch code...💀

  • 💀To all you soldiers barely holding on with Googled code, now feeling your limits...💀

  • 💀"Since we're going at night anyway..." To all you soldiers who slapped a plan together and are now trembling in fear...💀

  • 💀To the soldiers who abuse the database every night...💀

  • ⛔ Anyone who wants to join KILL-9 SQUAD... ⛔

Need to know before starting?

  • ⛔ Stay away if you are one of these people ⛔

  • 💀 Begone, those who do not know Spring and Spring Boot (this trial is yet too early for you) 💀

  • 💀 Begone, those who say they've only printed "Hello World" (You who know nothing of true suffering...) 💀

  • 💀 Begone, those who have yet to experience the pain of deployment (enjoy your peace until that day comes...) 💀

Hello
This is KILL-9

1,787

Learners

86

Reviews

133

Answers

4.9

Rating

1

Course

Declaration of the System Terminator

 

Boring lectures of Inflearn, be afraid.

Everything ends with my arrival.

Your expensive tuition fees? Don't make me laugh.

I will destroy everything with killer cost-effectiveness.


Instructor Introduction

Instructor Name

KILL-9

 

Title 📛

System Terminator

Specialty 🔪

kill -9       # "Process Execution"
rm -rf        # "Data Massacre"
chmod -R 000  # "System Imprisonment"


"Bugs? Hacking? Don't make me laugh. You can't rule the system with those petty tricks. I destroy it head-on."

(The alert() vulnerability on the Inflearn lecture introduction page was my debut work. Now I use more powerful weapons. - This is for real.)

Hobbies 💣

Organizing Outlets     # "Code is best when unplugged."
CPU Torture           # "I feel alive when the fan noise echoes."
Collecting Trophies    # "Core Dump"

Motto 🔥

"Cords are meant to be pulled." 

"Bugs are fixed by killing them."

"LGTM (Looks Gone To Me)"

Warning 🧨

"No need for formalities. Just feel free to call me Kill-gu Hyung."

"If you ask questions using polite honorifics, I'll cast rm -rf."

 

Communication Point 📡

kill9.no.mercy@gmail.com  # "For sending commands outside of lectures. Do not expect an ACK."

 

⚠️ CONFIDENTIAL: DO NOT LOG ⚠️

# Actually... I'm just an ordinary developer working quietly at Kakao...
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Curriculum

All

67 lectures

Published: 
Last updated: 

Reviews

All

86 reviews

4.9

86 reviews

  • dkswhdgur2468873님의 프로필 이미지
    dkswhdgur2468873

    Reviews 3

    Average Rating 5.0

    5

    24% enrolled

    Text-based lectures.. I love being able to dissect, savor, and enjoy them at my own pace. Just as intended by the lecture format, I love not having to pause unnecessarily or use the rewind button. I just hope you'll provide more lectures💀☠️

    • kill9
      Instructor

      💀 Welcome, I've finally met a true hacker 💀 Yes, this is it. Text is the best interface. - Mouse clicking? Waste of time - Video buffering? CPU abuse True masters use Command + F as a weapon. Like grep, extract only the information you want immediately. Text scrolling speed = Your learning speed However, there's an important warning: Never skip chapters 4 and 5. Many students miss the core of 스프링 배치 by skipping this part. If you thoroughly digest these two chapters, you'll reach a distinctly different level. Are you ready to deep dive?

  • hjung님의 프로필 이미지
    hjung

    Reviews 25

    Average Rating 4.8

    5

    50% enrolled

    Bro, keep the updates coming when versions upgrade! I'm counting on you, okay?!

    • kill9
      Instructor

      💀 [SYSTEM ACKNOWLEDGMENT] 💀 [INCOMING TRANSMISSION FROM BATTLEFIELD] =============================================== [KILL-9 RESPONSE PROTOCOL ACTIVATED] Yeah Jeonghun hyung 💀 [COMMITMENT PROTOCOL ENGAGED] The system continuously evolves. Every time there's a version update, the lectures will be upgraded together. 💀 [UPGRADE GUARANTEE]

  • qq211qq1594님의 프로필 이미지
    qq211qq1594

    Reviews 12

    Average Rating 4.4

    5

    32% enrolled

    Death's Spring Batch course, this is truly the path of a real system executioner...☠️ If you thought Spring Batch was just another ordinary batch framework, you're gravely mistaken. kill-9's course doesn't give you theory—it gives you real weapons to survive in the bloody battlefield of actual combat. Flat files? Fixed-length? Complex log files? Instead of just saying "figure it out yourself," he explains everything sharp as a blade so you can actually use it in real work situations. Even when choosing a single delimiter, you'll understand "why it has to be done this way." Code, explanations, practice, execution commands... the entire course is filled with the mindset of "this is real combat." You're not just learning—you feel like you're becoming a 'batch terminator.' And the more you listen, the more confidence builds that someday you too will be able to leave a mark on systems with a single line of open source code. Batch prepared for death—are you still hesitating? The moment you take this course, you too become a true member of the 'kill-9 squad.' ☠️🔥

    • kill9
      Instructor

      💀 System Terminator KILL-9 Course Review Confirmation Complete 💀 Such a killer course review... My system almost froze for a moment. **"kill-9 squad"** This expression is too powerful. My kernel shook. So? I adopted it immediately. From now on, we are the "kill-9 squad." From now on, you're not just developers. We are the system terminator squad. rm -rf mediocrity kill -9 boredom Welcome to the kill-9 squad, member. Squad member certification takes place on the battlefield within the course. We're not just some developers, we're the system terminator squad. Welcome to the kill-9 squad, member. - KILL-9 (Welcoming new squad members)

  • serverengineer님의 프로필 이미지
    serverengineer

    Reviews 81

    Average Rating 4.9

    5

    21% enrolled

    • kill9
      Instructor

      Thanks, javarunner bro 💀

  • ske060080922님의 프로필 이미지
    ske060080922

    Reviews 8

    Average Rating 4.8

    5

    62% enrolled

    Kilgu-hyung! I'd planned to leave a review after finishing the course, but I got so emotional watching the lectures that I'm writing it now. As Kilgu-hyung said early in the lecture, studying with text is truly difficult, but it definitely seems to stick in your mind more. Thanks to Kilgu-hyung's writing, it's great to learn so enjoyably and without difficulty. Thank you for such an incredibly cost-effective lecture, and I look forward to your future courses!

    • kill9
      Instructor

      ██████████████████████████████████ █ ╔═════════════════════════════╗ █ █ ║ 💀 KILL-9 TACTICAL RESPONSE TERMINAL 💀 ║ █ █ ║ [ STUDENT REVIEW RECEIVED ] ║ █ █╚═════════════════════════════╝ █ █████████████████████████████████ Crackle... Student review data received... Emotional circuit activated... ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ You were overwhelmed with emotion?.. I'm the one who's overwhelmed with emotion.. I can't help but shed tears after seeing this review. 💀 Yes, it will be etched into your brain as much as it was painful. But remember. Gi-hoon hyung.. You will soon forget it. That doesn't mean it's useless. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ [KILL-9 MEMORY STRATEGY] "Huh? Where did I learn this?" "Oh, I think I've seen this somewhere before?" "Oh, I knew this before?" Maximizing these **'Oh, where is this from?' moments** is my and our course's core strategy and goal. Even with just this illusion, the lecture is definitely valuable enough. Because this is also **a type of secondary index**. 💀 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Complete Recall < Partial Recall + Index >> Complete Oblivion Warrior, a KILL-9 index has been built in your brain. 💀 █████████████████████████████ [ WARRIOR ADVANCEMENT REPORT ] You've completed up to Chapter 4's final operation... Many soldiers actually give up at this point or don't even attempt to learn at all, but You've worked hard, warrior. If you've broken through Chapter 4's final operation, you'll be able to sufficiently follow Chapter 5. I assure you that after breaking through Chapter 5, you will **know Spring deployment better than anyone else**. And Chapter 6... I guarantee it. The difference in understanding between **those who have thoroughly learned Chapter 4's final operation and Chapter 5 and moved on to Chapter 6** and those who haven't is completely different. Beyond simply memorizing a list of knowledge, it will be a different level because **the operational principles will be understood as if piecing together a puzzle**. ━━━━━━━━━━━━━━━━━━━━━━━━━ **Hyung, you can do it. And (though it's too obvious to pursue) thank you for the valuable review.** 💀

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