sukora-stas / javaadvanced_mentoring

Global Java Mentoring Program: Advanced contains a set of modules aimed to enrich the expertise of senior level engineers in Java technologies stack.

Java 8 and 9, 10, 11+ Modul Practical Task

Necessary Tools

Java Development Kit 11+

Apache Maven 3.6.0+

Git 2.24+

Task

(1-2 stars)

1. Create maven project with 5 modules (see Java 9 modules) :

- jmp-bank-api
- jmp-service-api
- jmp-cloud-bank-impl
- jmp-cloud-service-impl
- jmp-dto

2. Create the fallowing classes under jmp-dto module :

- [User]
    String name;
    String surname;
    LocalDate birthday;


- [BankCard]
    String number;
    User user;


- [Subscription]
    String bankcard;
    LocalDate startDate;

3. Extend BankCard class with :

- CreditBankCard
- DebitBankCard

4. Create enum :

- [BankCardType]
    CREDIT
    DEBIT

5. Add Bank interface to jmp-bank-api with :

- BankCard createBankCard(User, BankCardType);

6. Add module-info.java which :

- requires jmp-dto
- export Bank interface

7. Implement Bank into jmp-cloud-bank-impl. Method should create a new class depending on the type:
8. Add module-info.java which :

- requires transitive module with Bank interface
- requires jmp-dto
- exports implementation of Bank interface

9. Add Service interface to jmp-service-api with :

- void subscribe(BankCard)
- Optional<Subscription> getSubscriptionByBankCardNumber(String)
- List<User> getAllUsers();

10. Add module-info.java which :

- requires jmp-dto
- export Service interface

11. Implement Service into jmp-cloud-service-impl. User Stream API, You can use Memory/DB for data storing :
12. Add module-info.java which :

- requires transitive module with Service interface
- requires jmp-dto
- exports implementation of Service interface

13. Use var for definition of local variables wherever it’s applicable.
14. Use lambdas and Java 8 features wherever it’s applicable.
15. Create application module.
16. Add module-info.java which :

- use interfaces
- requires module with Bank implementation
- requires module with Service implementation
- requires jmp.dto;

17. Demonstrate functionality of created classes. (3-4 stars)
18. Add a new default method for Service interface, which uses getAllUsers. Use LocalDate.now(), ChronoUnit и mapToLong.

- double getAverageUsersAge();

19. Add a new static method for Service interface, which returns true, if the user is over 18 years old.

- boolean isPayableUser(User);

20. Use Collectors.toUnmodifiableList() and method reference it’s applicable. (5 stars)
21. Create Exception class which will be used into orElseThrow for Optional from getSubscriptionByBankCardNumber().
22. Add a new method for Service interface and implement it. Demonstrate this method ino application module:

- List<Subscription> getAllSubscriptionsByCondition(Predicate<Subscription>);

23. Reimplement createBankCard with method reference (ex: CreditBankCard::new).
24. Add to module-info jar for each implementation module :

- provides [interface] with [implementation]

25. Add a module with Service implementation. Try to use ServiceLoader.load() for module loading.

References

• Java 8 new features
• Java 9 new features
• - modules
• Java 10 new features
• - var
• Java 11 new features