oliverzott / springbook

Spring Book - Example

BUGS: habuma/spring-in-action-5-samples#40

Initializing

1. Initializing spring project on start.spring.io

2. Initializing Git Repository and Push to remote

   1. Initialize local:
      https://www.youtube.com/watch?v=hks47h4C_nY
      https://www.youtube.com/watch?v=bvl4Kbe-qok
   2. Initialize remote: push and commit

3. Spring Tools 4

   • https://spring.io/tools/
   • https://stackoverflow.com/questions/31662983/how-can-i-install-the-spring-tool-suite-in-ubuntu

Project structure

• https://docs.spring.io/spring-boot/docs/current/reference/html/using-spring-boot.html#using-boot-structuring-your-code
• https://stackoverflow.com/questions/40902280/what-is-the-recommended-project-structure-for-spring-boot-rest-projects

TODO / Testing

• Add missing unit tests

Testing:

• https://developers.bluesnap.com/docs/test-credit-cards
• Visa / 4263982640269299 / 04/23 / 738

Remarks

• this::methodname ...Method Reference

  • https://www.geeksforgeeks.org/double-colon-operator-in-java/
  • https://stackify.com/streams-guide-java-8/
  • this refers to Object, not class
  • p. 809 / 1009

• enum
  (javabook p. 429 / 712 / 617)

• equals()

• hashCode()

• toString()
  (javabook p.483)

• List<>
  (javabook p.980)

• Array.asList(...)
  (javabook p.990)

• for (x : y)
  (javabook p.279)

• Streams, .filter
  (javabook p.1009)
  https://winterbe.com/posts/2014/07/31/java8-stream-tutorial-examples/

Chapter 1

Controller

"GetMapping cannot be resolved to a type":

• https://stackoverflow.com/questions/56712560/cannot-resolve-getmapping-in-spring-tool-suite

Bug in test for HomeController ...import org.junit.Test could not be resolved:

• https://stackoverflow.com/questions/61498856/tests-annotated-with-org-junit-test-are-not-recognized

Chapter 2

Lombock installation Problems:

1. Download lombok.jar
2. sudo java -jar lombok.jar
3. manually set eclipse path: /snap/eclipse/48/ Still not working!

General

• Model - View

• Model - View-Bibliothek

• Request Mapping / GetMapping

• Beans

Thymleaf

https://www.thymeleaf.org/doc/tutorials/2.1/usingthymeleaf.html
https://www.thymeleaf.org/doc/articles/standarddialect5minutes.html

• th:object ...line 15 design.html
  probably object, where form is stored

• th:each
  https://www.baeldung.com/thymeleaf-iteration

• th:field="*{...}"
  connects form input to taco dto name-property

Logging

(Java book p.930)

• JUL: java.util.logging

Validations

• @NotNull
• @Size(min=..., message="...")
• @NotBlank
• @Pattern
• @Digits
• @CreditCardNumber (Hibernate)

Problem: Needed to add to pom.xml:

Solution: https://www.baeldung.com/javax-validation

<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
</dependency>

Problem: Error Message now shown, instead: Whitelabel Error Page

Solution: http://forum.thymeleaf.org/Fields-object-functions-Spring-td3302513.html

Problem: Validation evaluation not working with taco design page!!! MAASSIV Error if not enough ingredients choosen?!? WTF Fucked-up-beyond-believe bullshit useles error message!

Solution: NONE

View-Controller

(p. 55)

????

Chapter 3

Goal:

• Use Jdbc Template from Spring
• Insert data with SimpleJbcInsert
• Declare JPA-Repositories with Spring Data

Add dependency

    <dependency>
    	<groupId>org.springframework.boot</groupId>
    	<artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>

H2 Database

https://www.youtube.com/watch?v=8QBJMxyXIqc https://howtodoinjava.com/spring-boot2/h2-database-example/
https://www.youtube.com/watch?v=8QBJMxyXIqc

• http://localhost:8080/h2-console/
• URL: jdbc:h2:mem:testdb

Remarks

General

• Domain Driven Design
• Repositories
• JPA / JDBC

Annotations / methods

• @Autowired
• @Repository
• jdbc.query queryForObject

**H2 / Hibernate **

• schema.sql ...for creating database-schema
• data.spl ...for populating database automatically by spring
• SQL Statements:
  • CREATE TABLE IF NOT EXITS (...NOT NULL)
  • ALTER TABLE ...ADD FOREIGN KEY...REFERENCES
  • DELETE FROM
  • DELETE FROM .. WHERE ...
  • CREATE TABLE ... IF NOT EXISTS

JdbcTemplate

• "query"
• "queryForObject"
• "update"
• PreparedStatementCreator
• KeyHolder

Java / Spring

• Converter ... to convert string-to-object for change that ingredients come from database instead hardcodet; auto-registration in Spring (Boot?) (see "Problems")

Links

JDBC

• https://docs.spring.io/spring-data/jdbc/docs/current/reference/html/#jdbc.repositories
• https://docs.spring.io/spring-data/jdbc/docs/current/reference/html/#repositories
• http://zetcode.com/db/jdbctemplate/
• https://www.baeldung.com/spring-jdbc-jdbctemplate
• https://www.baeldung.com/spring-jdbctemplate-testing

Converter

• https://stackoverflow.com/questions/35025550/register-spring-converter-programmatically-in-spring-boot
• spring-projects/spring-framework#11081
• https://www.baeldung.com/spring-type-conversions

Problems

####CONVERTER
..."when private List ingredients; was private List ingredients; it worked, but now it must be private List ingredients; because of the way it is saved in the database but it breaks at this point, how to fix it?" https://stackoverflow.com/questions/55093954/thymeleaf-failed-to-convert-property-value-of-type-java-lang-string-to-required/63328365#63328365

Keyholder - NullPointerException
habuma/spring-in-action-5-samples#40 http://mkaroune.e-monsite.com/pages/keyholder-getkey-return-null.html

Solution

• https://www.baeldung.com/spring-type-conversions
• https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/core/convert/converter/Converter.html

order.tacos

... List property of "order" class not saved from design to order forms! So wont be stored in database!?!