Some Trials & a lot of Errors: I tried a bunch of framework and other language and I usually feel overwhelm when its time to do something real with what I've learned. So that why I created this site, to write my progress and help some noob like me that stumble into the sames problems.

Law of 100

By Chris on July 25, 2021

I recently watched a youtube video of Noah Kagan about an interesting idea he call the law of 100.

The name of the law is self-descriptive, you need to do something one hundred times to know if it worth it or if it will get traction. Doing it a 100 time give you the opportunity to experiment more, learn from your mistake and get better with time.
And if you’re doing it every day its remove the decision, you got to do it 100 times before you can think of stopping.
Depending on how you phrase it can provide you with a tangible goal to reach that not out of your control (doing 100 video vs making 100 bitcoin)

Noah explain 9 step to make it work.
1-Pick your time (day)

There is an old saying if it’s not on the calendar it’s ain’t happening. In the video, he talks about a day, but I would push to at what time you will do it. In the morning? At 8h?

2-Reduce the friction

Want to shoot a youtube video? Have your camera ready so you don’t worry about it.
Want to play more guitar? Have your guitar out in your living room.
I remember Ramit talking in one of his post or interview how he made it easier to go to the gym every day by having his gym cloth ready for the next day.

“I realized I needed to put my gym clothes right near the floor with the shoes right there, so when I got out of bed my feet hit the shoes. Once I did that, my gym attendance went up.”

3-Have accomptability buddy/partner

Having someone that can call you out on your shit is great, you can even put a bet on it with beeminder or stick it.

4-Join a community

Having a community of like minded people is great. It motivate you and you can talk to other that have or had the same issue you’re having. You can check the 100days project (LINK), which is a project where creative must post a creation on their instagram every day for 100 days. If your goal is more business oriented checkout Noah group at okdork/group.

5-Take a break

This one is a bit counter-intuitive. If you’re not feeling it, maybe you just need to take a break go for a walk, take a nap and come back refresh to work on your task. I would push it a little and plan for a break. Sure someday you feel like going forever, but doing that every time without any break you will eventually burnout from what you’re trying to accomplish.

6-Notice what working

Notice what doing well and do more of that. That feeling of making progress will motivate you even more.

7-Have a clear why

Remind yourself daily of why you’re doing this, maybe your learning a language to impress someone or meet a special someone.

8-Make it fun

If it’s not fun, take a step back to see what part aren’t fun and what part are. Focus more on the part of what you’re doing that are fun or change a bit the not fun part to make it fun. Can you outsource the part you don’t like? Can you change the time of day you’re doing it to make it more interesting? Can you track something that might give you a sense of progression to motivate you?

9-Reward yourself

Have a reward at the end of you 100 to look forward too, it can be a trip, in can be going out. Something that will give that extra motivation to keep going forward.

Doing it 100 days consecutively touch another point: Consistency is king, one prime example of that is marketing legend Seth Godin. He writes a blog post at least every day since he started is blog. While Seth was already known when he started it, its helped him reach a bigger audience that he could ever imagine.

I’m trying a mini law of one hundred, which is to write something, anything, for 100 days. The goal is to at some point take it to another 100 posts on this blog. Next step would probably to publish one a day for 100 days, but let not get too much ahead of ourselves.

Posted in link, productivity, tips | Tagged lawOf100, Noah Kagan, productivity, Seth Godin, Sinbad, The 100 days project, tips | Leave a response

Reading 100 books before 40

By Chris on July 8, 2021

Awhile ago, I’ve decided to read 100 books before I hit forty. I’ve already read about 34 books in the last two years when I’ve decided to do this challenge and I think four years are remaining before the dreaded forty. Now that I have forty I just wanted to post the list out there 😀

Why read more books why not something else. I think reading is great to help structure your mind, discovers new word, and expand your imagination. I’m not the only one, look at Ryan Holiday on how and why you should read more or at Ramit Seti saying book being the best investment. I think reading make you a better reader too, you read faster, retain the information faster. Personally, I tend to read more non-fiction that fiction and read fiction faster. I managed to reach the fated 100 book before forty and even read a few more.

Here is the list of book from when I’ve started this to when I’ve finished it:

Don’t make me think
4 hour work week 2st edition
Art of start
Nudge
Sway
I will teach you to be rich
100$ startup
Montley Fool: The million dollars portfolio
Back of a napkin
The dip
Getting things done
59 seconds
Linchpin
Rework
Game frame
Smart couple finish rich
Travailler sans y laisser sa peau
L’art de negocier
Les bon couples font les bon comptes
Influence
Predictably Irrational
How to win friend and influence people
Le grand voyage 1er partie
Crowdsourcing
The game (neil strauss)
Game of throne (audio)
Clash of Kings (audio)
A storm of sword (audio)
A feast for crows (audio)
Dancing with dragons (audio)
48 laws of power
Les Chevaliers de L’emeraudes: Feu dans le ciel
Choose yourself
Hunger games I

Prior 2015 (34 books 8 fictions 26 non fictions)

2015 (26 books 13 fictions 12 non fictions)

(I realized here the in the last year or 2 I’ve read 34 book so I decided to make the push to 100)

Hunger games III
Brave new world
1984
The first 20h
L’or ménager
How Children succeed
Hitchhiker guide to the galaxy
CE – Les dragons de l’empereur noir
Lean Startup
Bird by bird
Restaurant à la fin du monde
La nuit des temps
The Flinch
Mastery
World war Z (audio)
Divergent
The martian (audio)
Geisha
Letter to a fiction writer
A la recherche du mouton sauvage
Principle 80/20
La vie, l’univers et le reste
The art of seduction (audio)
Moonwalking with Einstein
Warren Buffett, l’homme le plus riche du monde
Salut et merci pour le poisson

2016 (12 books, 4 fictions, 8 non-fictions)

Globalement inoffensif
Né pour gagner – Zig Ziglar
Déclin de la république romaine
Thirty million word
AC Underworld
Just do the work
Ego is the enemy
Je suis ton père
Zero to one
Zen and the art of motorcycle maintenance
The obstacle is the way
The war of art

2017 (20 books, 4 fictions, 16 non-fiction)

Deep work
Whole brain child
The subtle art of not giving a fuck
Fahrenheit 451
Nobody read your shit
Dale Carnegie – the 5 essential people skills
Instinct de survie
La mort d’Ivan Illitch
This will make you smarter (audio)
How to talk so kids will listen …
Money, master the game
Your first dollar
The daily stoic
Peaceful Parent, Happy kids
Barking up the wrong tree
Le horla
Your move
Celtes et gaulois
Vercingétorix
La véritable histoire de Marc-Aurèle

2018 (12 books, 3 fictions, 9 non-fictions)

Sapien
Digital Fortress
Essentialism
Ready player one
Unshakeable
No drama discipline
Da Vinci Code (FR)
Recession Proof Graduate
Love yourself (59 pages)
Perennial Seller: The Art of Making and Marketing Work that Lasts
Principle by Ray Dalio
Factfulness

Total: 104 books, 32 fictions, 72 non-fiction

All these 104 books were read cover to cover.

These following were just skim and taken on out of curiosity:

L’affiliation (Affiliate Marketing book)
How to web comic
Power of habit
The now habit (I don’t remember reading it)
Dangerous women (Only read GRRM story)
4 hour body
4 hour chef
Play for a living
SPQR
Tools of titan

Programming and Software engineering

I didn’t include programming and software engineering book since I usually jump around the book to read stuff I want to improve.

Effective java
Hardcore java (prog)
Hibernate recipe (prog)
Clean code (prog) (Note: I did read it cover to cover, twice…)
Clean coder
Code Complete
Web analytics (fr)
Google analytic (3rd edition)

Posted in book | Tagged book, books, List | Leave a response

To go faster we must first go slower

By Chris on July 1, 2021

Sometimes the deadline is yesterday or sometimes your boss wants the change now. Maybe the clients have an important feature that he thought he could do without dev but realised one day before the big marketing splash what he wanted to do is not working.

These changes are easy, no problem. I will do it in a flash. By now you probably know the story, it’s not easy to simply go fast, we forget basic things or completely forget (or even worse forgo) testing a critical part of the system that change might have an impact on.

Fast forward today I relived that exact situation and honestly it’s not my first time, but I get caught every time. Recently I made a simple script that updates some content in the db. Easy peasy, worked fine in my local db. I put up the PR and then fixed for some part the others have commented on and then merged on the main branch. Once the service was pushed to dev, it was in a crashloopback. It was because the dev db had way more data to process than my local db. The script would still be running when the health probe would check if the service was running and would stop the service since it wasn’t responding.

I made the fix then pushed it after running around to find someone to approve off-hour. Once the fix was pushed, it crashed again, but this time because the dev db had some corrupted data that would stop the script. I fixed the script to cover that edge case to then released it again. Beyond and behold, someone else merged right after so the server restarted before finishing the script. I’ve republished the script and finally, after three days, it was running and working on dev environment.

Notice that if I had backup the dev db and restored it on my local one I would probably have found all these problems. Perhaps in the initial pull request if I waited a bit for more dev to review it the problem would have been noticed earlier and fixed beforehand. If I’ve checked if other pull requests for the same service are ongoing there wouldn’t be a merge right after the script is merged.

That’s why when you need to go faster you must first go slower. You want to quickly deliver that api to the client, give them an example of the expected json first before starting any code. Do pull requests with only the change in the swagger file so others can review if everything makes sense. The time you take before will be time you save later down the line.

Posted in db, prog, rant, tips | Tagged rant, reflexion | Leave a response

How to get 70 Millions with only a 5$ investement!

By Chris on June 22, 2021

There is a 70 M lottery draw this week plus 70 one million prizes, I know this is no powerball, but here in Canada we are pretty excited. Even my wife is like: “We need to buy a ticket”. And she bought one with her father because 35M is still an insane amount of money. Well when the draw was 50M or “just” 30M it was still an insane amount of money, enough to change your life (sometime for the worst).

I usually don’t buy lottery tickets, but when I do, it’s for the fuzzy feeling of what I will do if I win the jackpot. I would probably try to figure out what I need from it to generate a decent income each year to live a good life. From there, the rest would be to give away to family, friends and charity and maybe some upgrade (my beat up toyota definitely needs an upgrade). What weird we almost always imagine ourselves what it would be like to win the jackpot but never think about the secondary prize. Winning a million is nice too, but not life changing like 70M.

I’ve met people who seem to consider lotteries like an investment. I even heard some crazy story of actually robbing a bank to buy lottery tickets and use the winning to pay back the loan (True story, there’s bank manager lending himself some money to buy a lot of ticket).

While putting money in the stock market may seem like playing in a casino, you are still buying an asset (except if you bought Theranos) and while it may go down in value, its value is likely to be higher than your lottery ticket the day after the draw.

Now back to work! I wish you all good luck and if you win don’t forget to give some back to your communities.

Note: There is no tax on lotteries here in Canada, because let’s be honest, lotteries are already a tax on the poor.

Posted in rant | Tagged lottery | Leave a response

How to remove array element in mongodb in java?

By Chris on June 17, 2021

In the previous post, we discuss own we change from using mongorepository to using directly mongodb method to access and modify directly the object in db.
In this posts we look at code that was deleting with mongorepository and change it to use directly mongodb method with MongoTemplate.

Using MongoTemplate is faster and less likely to have error due to concurrency.

Here a example of the code original code with mongorepository:

@Autowired
private MongoContentRepository mongoContentRepository;
			
private void removeStudentFromSchool(final Student student) {
   Optional<School> optionalSchool = mongoContentRepository.findById(student.getSchoolId());
		if (optionalSchool.isPresent()) {
            School school = optionalSchool.get();
            List<Student> students = school.getStudents();
            if (students != null && !students.isEmpty()) {
                Optional<Student> optionalStudent = getStudentInSchool(students, student);
                optionalStudent.ifPresent(studentInDb -> students.remove(studentInDb));
				school.setStudents(students);
				mongoContentRepository.save(school);
			} 
		}
    }

To do the same thing by calling the mongodb operator pull with MongoTemplate
Source: https://docs.mongodb.com/manual/reference/operator/update/pull/

Doing a pull directly in a mongodb query work like this:

db.getCollection('contentDetails').update(
    {_id : "1000102088"},
    {$pull: { "students": {_id : "1000102183", name: "John Smith"}}},
    {multi: true}
)

In Java it’s translate to this:

public void removeStudentInSchool(String schoolId, Student student) {
	mongoTemplate.updateFirst(
			Query.query(Criteria.where(CRITERIA_ID).is(schoolId)),
			new Update().pull("student", Query.query(Criteria.where(CRITERIA_ID).is(student.getId()))), COLLECTION_NAME);
}

So if we change the original code to use Mongo template it look like this:

public void removeStudentInSchool(String schoolId, Student student) {
	mongoTemplate.updateFirst(
			Query.query(Criteria.where(CRITERIA_ID).is(schoolId)),
			new Update().pull("student", Query.query(Criteria.where(CRITERIA_ID).is(student.getId()))), COLLECTION_NAME);
}

private void removeStudentToSchool(final Student student) {
	Optional<School> optionalSchool = mongoContentRepository.findById(student.getSchoolId());
	if (optionalSchool.isPresent()) {
		School school = optionalSchool.get();
		List<Student> students = school.getStudents();
		if (students != null && !students.isEmpty()) {
			Optional<Student> optionalStudent = getStudentInSchool(students, student);
			optionalStudent.ifPresentOrElse(studentInDb -> contentCollection.removeStudentInSchool(studentInDb.getId(), details), 
											() -> log.debug("{} already remove from school {}",student.getName(), school.getName()));
	}
}

Like updating in mongodb removing with the $pull operator is atomic, so it solved the concurency problem.

How to update an entry in an array in mongodb with java MongoTemplate?

By Chris on June 10, 2021

We had at work a piece of code that was using mongorepository and updating the arrays of the object on a collection instead of using mongodb method directly.
The way it was coded had a big issues with concurrency and we were losing update because of it.
The problem we had with the way it was updating the array and saving using mongorepository and we are going to fix it using directly mongo queries with MongoTemplate.

Example of code with mongorepository

@Autowired
private MongoContentRepository mongoContentRepository;
			
private void addStudentToSchool(final Student student) {
        Optional<School> optionalSchool = mongoContentRepository.findById(student.getSchoolId());
	if (optionalSchool.isPresent()) {
		School school = optionalSchool.get();
		List<Student> students = school.getStudents();
		if (students != null && !students.isEmpty()) {
			Optional<Student> optionalStudent = getStudentInSchool(students, student);
			optionalStudent.ifPresentOrElse(studentInDb -> {
				if (hasStudentChanged(studentInDb, student)) {
					students.remove(studentInDb);
					students.add(student);
				} 
			}, () -> students.add(student));
			school.setStudents(students);
		} else {
			school.setStudents(List.of(students));
		}
		
		mongoContentRepository.save(school);
	}
		
}

There are a lot of things wrong here.
It saving the whole object each time, which means if there a student is save in mongodb while another one is being save in a longer transaction, it will override the first update.

Using MongoTemplate

You can prevent that problem, by using directly mongo queries with MongoTemplate
Reference: https://docs.mongodb.com/manual/reference/operator/update/positional/

db.getCollection('content').update(
	{_id : "1000102088"},
	{$set : {"student.0.name" : "Joe Smith"}}
)

Or even better (in case the operation might change the order of the element in the array):

db.getCollection('content').update(
	{_id : "1000102088", student: {$elemMatch: {_id : "1000102177"}}},
	{$set : {"student.$.name" : "Joe Smith"}}
)

What does that look like in Java :
If we take the first query and convert to the equivalent code with MongoTemplate:

public void addStudentInSchool(String objectId, Student student, int index) {
	mongoTemplate.updateFirst(
		Query.query(Criteria.where("_id").is(objectId)),
		new Update().set("student.$[" + index + "]", student), COLLECTION_NAME);
}

For the second query we get:

public void updateStudentInSchool(String schoolId, Student student) {
mongoTemplate.updateFirst(
	Query.query(Criteria.where("_id")
		.is(objectId)
		.andOperator(Criteria.where("student")
		.elemMatch(Criteria.where("_id").is(student.getId())))),
		new Update().set("student.$", student), COLLECTION_NAME);
	}

Note: WP code block seems to mess up the indentation.

End result

If we take our initial code and use our mongo template code we get the following end result.

Let’s update addStudentToSchool with MongoTemplate instead of mongoContentRepository:

private static final String COLLECTION_NAME = "schoolCollection";
private final MongoTemplate mongoTemplate;

public void addStudentInSchool(String schoolId, Student student) {
	mongoTemplate.updateFirst(
			Query.query(Criteria.where("_id").is(schoolId)),
			new Update().addToSet("student", student), COLLECTION_NAME);
}

public void updateStudentInSchool(String schoolId, Student student) {
	mongoTemplate.updateFirst(
			Query.query(Criteria.where("_id").is(schoolId).andOperator(Criteria.where("student").elemMatch(Criteria.where("_id").is(student.getId())))),
			new Update().set("student.$", student), COLLECTION_NAME);
}

private void addStudentToSchool(final Student student) {
	Optional<School> optionalSchool = mongoContentRepository.findById(student.getSchoolId());
	if (optionalSchool.isPresent()) {
		School school = optionalSchool.get();
		List<Student> students = school.getStudents();
		if (students != null && !students.isEmpty()) {
			Optional<Student> optionalStudent = getStudentInSchool(students, student);
			optionalStudent.ifPresentOrElse(
        studentInDb -> contentCollection.updateStudentInSchool(school.getId(), student),
	() ->  contentCollection.addStudentInSchool(school.getId(), student));
	} else {
		contentCollection.addStudentInSchool(school.getId(), student);
	}
}

This worked fine for us and we stop having our mongdb update disappearing due to concurrency.

Why did it solve the concurrency issue ?

All $inc $set $unset $push $pushAll $addToSet $pop $pull $pullAll $rename $bit operations are atomic.
This mean if multiple $set or $addToSet are done in concurrency all the operations and lock that entry.

For more information on mongodb concurrency:
https://stackoverflow.com/questions/6997835/how-does-mongodb-deal-with-concurrent-updates
https://docs.mongodb.com/manual/faq/concurrency/

Hope It helped you and have a nice day.

Posted in java, mongodb, prog, tips | Tagged java, mongodb, MongoRepository, MongoTemplate | Leave a response

Books I’ve read in 2020

By Chris on May 30, 2021

At the beginning of 2020, I wanted to read more than my abysmal 2019 three books total. I’ve already read my 2019 total before the whole 2020 ‘situation’ hit. This made it harder for me to read since I was stuck at home most of 2020 and I usually read in my commute. Nonetheless, I managed to read 12 books last year. Here is the rundown of all the books I’ve read last year, I think I might do a full reviews of some of the non-fiction books later this year, we’ll see.

Stillness is the Key

This is the third installment of Ryan Holiday books on stoicism, the two others being Obstacle is the way and Ego is the enemy.

Sometimes when everything seems to get faster, more stressful and even crazy around us. While some philosophy might say to go with the flow, stoics show us that deliberately slowing down is what you should do. By slowing down, you will notice what usually goes unnoticed and, in a Matrix like slow motion montage, dodge what is unimportant and focus on what truly matter.

If you’re into stoicism or like the obstacle is the way or ego is the enemy, then is book is definitely for you. If not I would recommend reading the Obstacle is the way first, I found that some idea are repeated and Obstacle made more of an impact on me. Note that I say this and I’ve read Ego is the enemy first.

Piège au royaume des ombres

Piège au royaume des ombres is the third installment of the French Fantasy Fiction ‘’Les Chevaliers d’Émeraude’’ series. Kira has finally reached an age where she can show what she is capable of and set on an expedition with Wellan, her master and other fellow knights and squire.

I tend not to review too much fiction because the fun of it is to discover the story and reviewing quickly enters spoiler territory whereas non-fiction having a review will help you decide if the book talks about subject matter you want to expand on or not.

Everything is F*cked

From the author of The Subtle Art of Not Giving A F*ck comes a counter-intuitive guide to the problems of hope.

I really liked The Subtle Art of NotGiving A F*ck with his gritty writing and mind opening view so I was really excited when I’ve heard that Mark Manson was writing another book. While I liked the book, I would recommend reading first book before this one, they’re not mutually exclusive and can be read on their own. However, is first book is more packed with information and reflection than this one.

The Power of Creativity

A small book I bought a while ago seems to be part of a series by the same author. It gives some good advice even if it’s mostly stuff I already knew. Advice that is always good to revisit like what your audience demands vs your craft and that you should invest in your side project.

If you follow Seth Godin or read Steven Presfield non fiction you will know most of what he talks about in the book.

Dividend Investing for Everyone

It’s been awhile since I haven’t read a book about investing and I was looking for a way to invest that could create recurring revenue from investing. This book is short and sweet if you already know a bit about investing in general. However, the lack of a table of index is a bit annoying for this review though. He goes on explaining what is dividend investing and how it will generate more money for you that bond and saving account. The most interesting part of the book is when he shows how he picks his own dividend stock, what are his criteria and what type of dividend stock there is.

The Lost Symbol (Fiction)

Note I’ve read this one in french, Le symbole perdu by Dan Brown.

The sequel to the famous Da Vinci Code, we follow again professor Robert Langdon, this time involved in a plot linking the Freemason and the founding father.

I won’t spoil you much, if you liked Da Vinci Code you will like this one. I follow the same formula of his last book, a little too much in my taste. I had the impression that in some part of the book I was just rereading Da Vinci code, but except for being in Paris we’re in Washington.

Conspiracy

Another book from Ryan Holiday, this time not really the kind of book we are you to get from him. Holiday dissects the involvement of Billionaire Peter Tiel in helping bring down publisher Gawker by helping Hulk Hogan in his trial against them without Hogan knowing it.

Tiny MBA

When I saw one of stackingthebricks author wrote a book I immediately ordered it. Unfortunately it didn’t live up to the level of their amazing long form post they usually do. It’s more like someone was following every business thought leader and CEO and collected all theirs insightful tweets then put them in a book. While some can really be inspiring and insightful, you kind of eager to want more after going through it.

Stop People Pleasing

Stop people pleasing is about how to balance helping other people and not being a yes man that other people don’t value your time. I think I got this one through a newsletter that sells books for one dollar and sometimes gives freebies.

The main takeaway of the book: is to learn what you want to say yes to and no to, common phrases to use to imply a no without saying it and stay away from manipulators.

Live of the Stoics

A third book from Ryan Holiday this year, this one is more in the vein of the Daily stoic I’ve read through in 2018 (http://cjacques.me/the-20-books-ive-read-in-2017/). He goes through the list of all the major stoics from the founder of stoicism Zeno to philosopher king (emperor) Marcus Aurelius. I’m kind of a sucker for this book because it’s a mix of things I like to read about, Roman history and philosophy. If you’re interested in one or both of these subjects it’s definitely a good read.

The Art of Learning

Josh Waitzkin, former chess prodigy and martial Tai Chi World champion, walk us thought is life and how he learned to master those two disciplines in this self-help memoir.
While Waitzkin can kinda sometime sound like a d*&k and that can be off putting at time, he goes deep into what was going in his mind in different key learning points in his life. While being world class might not be your thing, understanding what got them to that point can definitely be useful.

Learn Like a Polymath

I got this one on a kindle sale. It might be a good idea to do the same. There are some tips and tactics that I’ve probably read in other books like space your learning, deconstruct what you learn to a manageable piece. However, instead of focusing these on the broader concept of learning the author apply them at connecting knowledge between disciplines.

If you’re interested in learning in general or searching for a way to connect knowledge between your field of interest you will probably find some good nuggets here and there.

Posted in book | Tagged 2020, book, books, List, reviews | Leave a response

Assert an Exception is Thrown in JUnit 4 and 5

By Chris on May 19, 2021

This is old news, but having work with big bank and insurance companies they tend to stick with the old version of java and they’re underlying libraries, I’ve finally been expose to new ways of testing exception with junit.

I use to test exception by adding an expected right after the @Test annotation.
@Test(expected = NullpointerException)

However they’re many other ways to do that with only junit5 and mockito

Option 1: Stinking with junit4 you can define an expected exception:

@Rule
public ExpectedException bob = ExpectedException.none();

@Test
public void testShareContentFileConflict() {

    bob.expect(ConflictException.class);
    bob.expect(hasProperty("accountId", is(MASTER_ACCOUNT_ID)));

    Mockito.when(service.getSharedId(MASTER_ID, MASTER_ACCOUNT_ID, AFFILIATE_ACCOUNT_ID)).thenReturn(null);
    Mockito.when(service.shareContent(MASTER_ID, MASTER_ACCOUNT_ID, AFFILIATE_ACCOUNT_ID)).thenThrow(new ConflictException(MASTER_ACCOUNT_ID, "Error occurred"));

    // call manager
    String returnedAffiliateContentId = contentManager.shareContent(MASTER_ID, MASTER_ACCOUNT_ID, AFFILIATE_ACCOUNT_ID);

    // validations
    Assert.assertEquals(AFFILIATE_CONTENT_ID, returnedAffiliateContentId);
    Mockito.verify(service).shareContent(MASTER_ID, MASTER_ACCOUNT_ID, AFFILIATE_ACCOUNT_ID);
}

Option 2: JUnit5 introduces the assertThrows method for asserting exceptions.
This takes the type of the expected exception and an executable functional interface where we can pass the code under test through a lambda expression.

@Test
public void whenExceptionIsThrown_thenAssertionSucceeds() {
    Exception exception = assertThrows(NumberFormatException.class, () -> {
        Integer.parseInt("1a");
    });

    String expectedMessage = "For input string";
    String actualMessage = exception.getMessage();

    assertTrue(actualMessage.contains(expectedMessage));
}

Option 3: Using mockito & assertJ:
If you’re using mokito and assertJ in your test already, there an another clean way to do it. It’s so far my favorite.

given(xxx).willThrow(new MyException())
when {() -> myService.doSomething()}
then(caughtException()).isInstanceOf(MyException.class)

They are other way to do it just with mockito using doThrow, thenThrow and spy which are explained here.

Posted in java | Tagged assertJ, java, junit, junit4, junit5, mokito, testing | Leave a response

Solving LazyInitializationException with sonar rules @Transactional method called from another method doesn’t obtain a transaction

By Chris on May 12, 2021

We recently added a feature that allowed direct modification on our content for some client vs using the same path (queues) that the batched content is using.
Our user were really happy with it, but after our team implemented the new feature, we started having some LazyInitializationException.

exception for that problem

org.hibernate.LazyInitializationException: could not initialize proxy [com.company.dbservice.model.Image#1004291143] - no Session
     at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:170)
     at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:310)
     at org.hibernate.proxy.pojo.bytebuddy.ByteBuddyInterceptor.intercept(ByteBuddyInterceptor.java:45)
     at org.hibernate.proxy.ProxyConfiguration$InterceptorDispatcher.intercept(ProxyConfiguration.java:95)
     at com.company.dbservice.model.Image$HibernateProxy$aWvtUHZY.getContent(Unknown Source)
     at com.company.dbservice.search.resolver.ImageResolver.getImageUrl(ImageResolver.java:50)
     at com.company.dbservice.search.resolver.ImageResolver.getContentImageUrl(ImageResolver.java:34)
     …..
     at com.company.dbservice.aop.ReadOnlyRouteInterceptor.proceed(ReadOnlyRouteInterceptor.java)
     at com.company.dbservice.sqs.reader.MessageHandler.processMessage(MessageHandler.java)
     at com.company.dbservice.sqs.reader.MessageHandler.receiveMessage(MessageHandler.java)

After looking at, it those errors seem to keep happening to object in object in object that were not needed anyway so the unnecessary acces were remove to prevent processing these object. It a solution you might say but this don’t solve the underlying issue.
Here an example of the table surrounding the object.

When I look in new relic the next they I notice that the error were still happening.
This time it was for an object that was needed. After some digging, I found out that the new endpoint for the direct route didn’t have the @Transaction annotation. It was calling the same code to save and process the object the batch part was using though.
For those who don’t know @Transactional tells spring to create a proxy around the object. The proxy intercepts calls to the object from other objects. The proxy does not intercept calls within the object.

So to fixed we had to add @Transactional on the method that is invoked from “outside” and it fixed the problem.

Posted in java | Tagged Exception, hibernate, java, LazyInitializationException | Leave a response

Why does Map.of not allow null keys and values?

By Chris on March 2, 2021

Once upon a time an engineer with years of experience encounter something so basic he doesn’t understand why he didn’t encounter it sooner.

This week we had a strange error in our log stating that should have a null values in a map.

After some digging in the service where that log was found, it seems to be not coming from us…

But why can’t a map have a null values. It’s easy to understand why we can have a null key value but why can’t the value be null?

Well it make sense, why keep an empty record in a key when you could just remove the key and it’s not in the map it means it’s null. That free up the map to make it more efficient.

If you straight up initialize a map with Map.of() and include a null value, it will throw a null pointer exception. However, if you do it with a HashMap it will work fine. You can even have null key that way. Most modern implementation of map won’t allow null in their keys or values.

If you want a better explaination checkout this stackoverflow answer: Why does Map.of not allow null keys and values?

Here the TL;DR:

Allowing null in collections is by now seen as a design error. This has a variety of reasons. A good one is usability, where the most prominent trouble maker is Map::get. If it returns null, it is unclear whether the key is missing or the value was null. Generally speaking, collections that are guaranteed null free are easier to use. Implementation-wise, they also require less special casing, making the code easier to maintain and more performant.

Null elements, keys, and values will be disallowed. (No recently introduced collections have supported nulls.) In addition, prohibiting nulls offers opportunities for a more compact internal representation, faster access, and fewer special cases.

Since HashMap was already out in the wild when this was slowly discovered, it was too late to change it without breaking existing code but most recent implementations of those interfaces (e.g. ConcurrentHashMap) do not allow null anymore and the new collections for the factory methods are no exception.

So disallowing null had some technical reason but it was also done to improve the robustness of the code using the created collections.

Posted in java | Tagged java, java.util.Map, maps, null | Leave a response

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