- The Nature of Spring Boot:
- Spring Boot is like the Tao, providing a harmonious way to develop Spring applications.
- It embodies simplicity, allowing developers to focus on the essence of their application.
- Spring Boot follows the principle of "wu wei," effortlessly taking care of the mundane tasks.
-
Simplicity:
- Spring Boot embraces simplicity, providing sensible defaults and minimizing configuration.
- It allows developers to express their intentions clearly, without unnecessary complexity.
-
Convention over Configuration:
- Spring Boot follows the path of least resistance, favoring convention over explicit configuration.
- It provides a smooth journey, allowing developers to follow the well-trodden path.
-
Opinionated Defaults:
- Spring Boot offers opinionated defaults, like a wise sage guiding the way.
- It makes decisions on behalf of the developer, promoting best practices and reducing cognitive load.
-
The Spring Initializr:
- The Spring Initializr is like a gateway to enlightenment, providing a starting point for the journey.
- It offers a simple path to generate a project structure, with the necessary dependencies.
-
The Choice of Build Tools:
- Spring Boot projects can be built using Maven or Gradle, like two paths to the same destination.
- Each build tool has its own merits, and the choice lies in the hands of the developer.
- Task: Create a basic Spring Boot application that prints a profound philosophical quote.
- Instructions:
- Use Spring Initializr to generate a new Spring Boot project with the required dependencies.
- Create a main class annotated with
@SpringBootApplication
, symbolizing the entry point to wisdom. - Implement a
CommandLineRunner
to print a profound philosophical quote when the application starts. - Run the application and contemplate the wisdom it imparts.
- Reflect on how Spring Boot embodies the principles of simplicity and ease of use in application development.
- Discuss how Spring Boot's opinionated defaults and auto-configuration align with the concept of "effortless action" in Taoism.
- The Essence of Spring Data JPA:
- Spring Data JPA is like a bridge between the realms of objects and relational databases.
- It simplifies the interaction with the database, abstracting away the complexities.
- It allows developers to focus on the essential aspects of data persistence.
-
The Repository:
- A repository is like a gateway to the database, providing methods to access and manipulate data.
- Spring Data JPA provides pre-defined repository interfaces, like ancient scrolls of wisdom.
- These interfaces offer a set of common operations, reducing the need for repetitive code.
-
The Entity:
- An entity is like a representation of a concept in the database, a manifestation of knowledge.
- Entities are annotated with JPA annotations, like sacred seals that define their nature.
- They encapsulate the structure and behavior of the data they represent.
-
The Dependencies:
- To embark on the path of Spring Data JPA, one must gather the necessary dependencies.
- The
spring-boot-starter-data-jpa
and the database driver are the essential tools for the journey.
-
The Database Connection:
- The database connection properties, like the URL, username, and password, are the keys to unlocking the database.
- These sacred keys are configured in the
application.properties
orapplication.yml
file.
-
The Entity Scanning:
- Spring Data JPA possesses the power to scan for entity classes in the specified package.
- It automatically creates the corresponding database tables, like a skilled artisan shaping the world.
- Task: Create a Spring Data JPA repository for managing
Philosopher
entities. - Instructions:
- Define a
Philosopher
entity class with attributes such asid
,name
, andschool
. - Create a
PhilosopherRepository
interface that extendsJpaRepository<Philosopher, Long>
. - Implement a service class that uses the
PhilosopherRepository
to save and retrievePhilosopher
entities. - Test the functionality by saving and retrieving
Philosopher
entities from the database using the data loader example we saw in class.
- Define a
π Practical Exercise: Implementing a Simple Spring Data JPA Repository for the ROBOTS exercise from last week!
- Reflect on how Spring Data JPA simplifies the interaction with the database, promoting a more intuitive approach to data persistence.
- Discuss how the repository interfaces in Spring Data JPA align with the concept of abstraction and encapsulation in philosophy.
-
The Query Methods:
- Spring Data JPA provides a way to create query methods by defining method signatures in the repository interface.
- These methods are like questions posed to the database, seeking specific knowledge.
- The method names follow a naming convention, and Spring Data JPA generates the corresponding queries.
-
Examples of Query Methods:
findById
: Retrieves an entity by its primary key, like finding a specific piece of wisdom.findAll
: Retrieves all entities from the database, like gathering all the knowledge in the world.findByAttribute
: Retrieves entities based on a specific attribute value, like searching for wisdom based on a particular criterion.countByAttribute
: Counts the number of entities with a specific attribute value, like measuring the prevalence of a certain idea.
-
Saving Entities:
- The
save
method provided byJpaRepository
is used to save entities to the database, like preserving knowledge for future generations. - If the entity is new, it will be inserted into the database, like adding a new idea to the collective wisdom.
- If the entity already exists, it will be updated in the database, like refining an existing concept.
- The
-
Updating Entities:
- To update an entity, one must first retrieve it from the database, like seeking the knowledge to be modified.
- The attributes of the entity can be modified, like evolving an idea based on new insights.
- The
save
method is then called to persist the changes, like recording the updated knowledge.
- Deleting Entities:
- The
deleteById
method provided byJpaRepository
is used to delete an entity from the database based on its primary key, like removing a specific piece of knowledge. - The
delete
method can be used to delete a specific entity instance, like discarding a particular idea. - The
deleteAll
method can be used to delete all entities from the database, like wiping the slate clean.
- The
- Task: Create a Spring Boot application that demonstrates basic database queries using Spring Data JPA.
- Instructions:
- Define a
Book
entity class with attributes such asid
,title
,author
, andgenre
. - Create a
BookRepository
interface that extendsJpaRepository<Book, Long>
. - Implement a service class that uses the
BookRepository
to perform basic database queries. - Test the functionality by saving, retrieving, updating, and deleting
Book
entities.
- Define a
- Reflect on how query methods in Spring Data JPA align with the concept of seeking knowledge and understanding in philosophy.
- Discuss the philosophical implications of saving, updating, and deleting data, and how it relates to the preservation and evolution of knowledge.
- Develop a simple wisdom repository using Spring Boot and Spring Data JPA.
- The application should allow users to store, retrieve, update, and delete wise sayings and philosophical quotes.
- Use Spring Boot to bootstrap the application and handle the server-side logic.
- Implement a
Wisdom
entity with attributes such asid
,quote
,author
, andcategory
. - Create a
WisdomRepository
interface that extendsJpaRepository
to perform database operations onWisdom
entities.
-
Step 1: Set up a new Spring Boot project with the required dependencies (Spring Web, Spring Data JPA, database driver).
-
Step 2: Define the
Wisdom
entity class with the necessary attributes and annotations. -
Step 3: Create the
WisdomRepository
interface extendingJpaRepository<Wisdom, Long>
. -
Step 6: Configure the database connection properties in the
application.yaml
file.
- Reflect on how the wisdom repository project aligns with the concept of preserving and sharing knowledge in philosophy.
- Discuss the role of technology in facilitating the dissemination and accessibility of philosophical ideas.