Himai Minh

You may find this post helpful :
https://coderanch.com/t/737952/certification/Deadlock

Please refer to the attached diagram. I put on a debugger and found out that t is thread-0, h is thread-1. thread-1 starts and runs its own run method and
thread-0 reference has nothing to do with thread-1 in this case.

Also, if you change your code into:
Thread t = new Threader(); Thread h = new Thread(t); h.start();

Then, h thread starts  and executes t thread's run method. This is a typical way to execute a thread which is equivalent to :
Runnable t = new Threader(); Thread h = new Thread(h); h.start();

There is a lot of learning curve regarding to writing a Spring boot web application with thymeleaf.
Here are some introductory examples to start with:
https://mkyong.com/spring-boot/spring-boot-hello-world-example-thymeleaf/
https://github.com/eugenp/tutorials/tree/master/spring-web-modules/spring-thymeleaf
https://www.baeldung.com/thymeleaf-in-spring-mvc

There is no definite answer why the setAttribute is used in one method , but not another.
As long as the methods needs to set the attribute and pass it along to the form , then the setAttributed method is used.

Also, Spring form provides some more library tags than html tags. When those library tags are needed to build the front end page, then use it.
Thymeleaf is very popular for building front end for Spring application now.

Maybe, you may find this tutorial using Git in NetBean helpful :
http://netbeans.apache.org/kb/docs/ide/git.html

Do you find this web site helpful?
It suggest people to implement Serializable interface for your class.
https://cwe.mitre.org/data/definitions/579.html

I found the speaker's github link:
https://github.com/danvega/data-jdbc-test/tree/master/src/main/java/dev/danvega/dao
You may want to compare your code with his to see if you miss anything.

Maybe, try to insert an integer as the id of the course and see.

Here is another similar example. You will see the entity Person has an id in the constructor.
https://www.journaldev.com/17053/spring-jdbctemplate-example

Topic: Pivoting into Quantum Computing Solving Industry Challenges with Cambridge Quantum
Speaker: Danika Hannon, relationship manager of Cambridge Quantum
Moderators: Dr. Sebastian Zajac (member of QPoland, Quantum AI Foundation) , John Barnes (founder of Entangled Positions),
Chris Bishop (chief reinvention officer, Improvising Careers) , Dr. Rafael Sotelo (co-founder of Quantum South)

Date time : Oct 23 13:00 EDT (US)
Sponsors: Cambridge Quantum, QPoland, Quantum AI Foundation, Entangled Positions, Improvising Careers, Quantum South, Association Quantum,
OrionX.net, QB-net, Minnesota / Washington DC/ Warsaw/ Toronto QC meetup groups

Sign up link  https://www.eventbrite.com/e/pivoting-into-quantum-computing-solving-industry-challenges-with-cq-tickets-174695477877

Is your Eclispe the latest version?

Reference:
https://stackoverflow.com/questions/61824506/couldnt-install-spring-tool-suite-could-not-be-installed-for-eclipse-luna

Topic: Quantum Communication
Speaker: Nitish Swami, phD candidate of Waterford Institute of Technology
Moderators: Pawel Gora (CEO of Quantum AI Foundation), Kareem El-Safty (Co-organizer of Alexandria Quantum Computing meetup), Olawale Ayoade (phD candidate of Baylor University)
Datetime: Sept 25 13:00 - 15:00 EDT
Sponsors: Cambridge Quantum, OrionX.net, Association Quantum, QB-Net
Two sign up options:
https://www.meetup.com/Washington-Quantum-Computing-Meetup/events/278796255/ or
https://www.eventbrite.com/e/quantum-communication-tickets-166584281069

Hi,
What other details printed on the console regarding to this RuntimeException?

Are you hard coding the customFakeName parameter? If so , try this:
ueryParams = "?customFakeName=name&fakeItTillYouMakeI=desc\n"

You may need to refer to this tutorial as a quick start :
https://dzone.com/articles/spring-cloud-and-spring-bootimplementing-spring-cl

We need to get more details about your project. With the screen shot you provided, it is hard for us to tell what was going on.