This document discusses how to build APIs productively using Spring Boot, Spring MVC, and Spring Data. It covers how Spring Boot helps with dependency management, embedded servlet containers, and auto-configuration. Spring MVC is described as providing simplicity in API exposure and serialization/deserialization. Spring Data provides standard repository implementations and abstraction for data access across different data sources, including support for caching.

1. TRILHA JAVA EE
CONSTRUINDO APIS DE FORMA PRODUTIVA COM
SPRING BOOT, SPRING DATA E SPRING MVC
Emmanuel Neri

2. PROBLEMA
Quais os obstáculos da construção de APIs?
Ambiente Objeto <—> JSON Acessos aos dados

3. AGENDA
Spring Boot
Spring MVC Spring Data

4. SPRING BOOT
GERENCIAMENTO
DE DEPENDÊNCIAS
EMBEDDED
SERVLET
CONTAINERS
AUTO
CONFIGURAÇÃO

5. GERENCIAMENTO DE DEPENDÊNCIAS
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<version>1.5.3.RELEASE</version>
</dependency>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.3.RELEASE</version>
</plugin>
</plugins>
</build>

6. GERENCIAMENTO DE DEPENDÊNCIAS

7. AUTO CONFIGURAÇÃO
@SpringBootApplication
public class AppConfig {
public static void main(String[] args) {
SpringApplication.run(AppConfig.class, args);
}
}
@EnableAutoConfiguration
@AutoConfigureTestDatabase
@AutoConfigureMockMvc

8. AUTO CONFIGURAÇÃO
mvn spring-boot:run -Ddebug
=========================
AUTO-CONFIGURATION REPORT
=========================
Positive matches:
-----------------
EmbeddedServletContainerAutoConfiguration matched:
...
DataSourceConfiguration.Tomcat matched:
...
Negative matches:
-----------------
ActiveMQAutoConfiguration:
Did not match:
RedisAutoConfiguration:
Did not match:

9. AUTO CONFIGURAÇÃO
/src/main/resources/application.properties
spring.profiles.active=dev
server.port=8090
server.context-path=/api
spring.http.encoding.charset=UTF-8
spring.datasource.url=jdbc:postgresql://localhost:5432/db
spring.datasource.username=postgres
spring.datasource.password=postgres
spring.datasource.driver-class-name=org.postgresql.Driver
spring.jpa.show-sql=true

10. AUTO CONFIGURAÇÃO
spring.profiles.active=
spring.mail.host=
spring.sendgrid.api-key=
flyway.enabled=true # Enable flyway
liquibase.enabled=true
spring.data.cassandra.cluster-name=
spring.data.elasticsearch.cluster-name=
spring.data.mongodb.database=test
spring.data.redis.repositories.enabled=true
spring.activemq.broker-url=
….
https://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html

11. EMBEDDED SERVLET CONTAINERS
mvn spring-boot:run
s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

12. SPRING MVC
SIMPLICIDADE NA
EXPOSIÇÃO DE APIS
ABSTRAÇÃO NA
SERIALIZAÇÃO /
DESERIALIZAÇÃO
FACILIDADE NA
LEITURA DE
PARÂMETROS
TRATAMENTO DE
ERROS
CONSTRUÇÃO
SIMPLES
ESTRUTURA DE
RETORNO

13. SIMPLICIDADE NA EXPOSIÇÃO DE APIS
@RestController
@RequestMapping("/customers")
public class CustomerController {
@RequestMapping(method = RequestMethod.GET)
public List<Customer> findAll() {
return customerService.findAll();
}
}
http://localhost:8080/customers

14. ABSTRAÇÃO NA SERIALIZAÇÃO / DESERIALIZAÇÃO
@RequestMapping(method = RequestMethod.GET)
public List<Customer> findAll() {
return customerService.findAll();
}
@RequestMapping(method = RequestMethod.POST)
public void save(@RequestBody BillDTO billDTO) {
billService.save(billDTO);
}

15. ABSTRAÇÃO NA SERIALIZAÇÃO / DESERIALIZAÇÃO
import com.fasterxml.jackson.annotation.JsonFormat;
public final class BillDTO {
@JsonFormat(pattern = "yyyy-MM")
private YearMonth yearMonth;

16. FACILIDADE NA LEITURA DE PARÂMETROS
@RequestMapping(value = "/byUk/{customerId}/{identifier}/{yearMonth}",
method = RequestMethod.GET)
public Bill findByUk(@PathVariable("customerId") Long customerId,
@PathVariable("identifier") String identifier,
@PathVariable("yearMonth") YearMonth yearMonth) {
return billService.findByUk(customerId, identifier, yearMonth);
}
@RequestMapping(value = "/search", method = RequestMethod.GET)
public List<Customer> search(
@RequestParam(value = "id", required = false) Long id,
@RequestParam(value = "name", required = false) String name){
return customerService.search(new CustomerSearchTO(id, name));
}

17. CONSTRUÇÃO SIMPLES ESTRUTURA DE RETORNO
ResponseEntity.ok(bill);
ResponseEntity.badRequest().build();
@RequestMapping(method = RequestMethod.GET)
public ResponseEntity ok() {
return ResponseEntity.ok().build();
}
200
400
200
{
"id":1,
"customer":{
"name":"Customer"
},
"carrier":{
"name":"TIM"
},
"identifier":"23326",
“yearMonth”:"2017/06"
}
ResponseEntity.status(UNAUTHORIZED).build(); 401

18. TRATAMENTO DE ERROS
@ControllerAdvice
public class GlobalExceptionHandler {
@ExceptionHandler(ConstraintViolationException.class)
public ResponseEntity<Set<ExceptionTO>>
handleError(ConstraintViolationException ex) {
final Set<ExceptionTO> erros = ex.getConstraintViolations().stream()
.map(c -> new ExceptionTO(c.getMessage()))
.collect(Collectors.toSet());
return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(erros);
}
@ExceptionHandler(Exception.class)
public ResponseEntity handleError(Exception ex) {
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
.body("O sistema se encontra indisponível”);
}

19. SPRING DATA
IMPLEMENTAÇÕES
PADRÕES
ABSTRAÇÃO NO
ACESSO AOS
DADOS
SUPORTE A
DIFERENTE FONTES
DE DADOS
CACHE

20. IMPLEMENTAÇÕES PADRÕES
public interface BillRepository extends JpaRepository<Bill, Long> {
‣ findAll()
‣ save(T object)
‣ save(Iterable<T> objects)
‣ flush()
‣ getOne(ID id)
‣ delete(ID id)
‣ deleteInBatch(Iterable<T> objects)

21. ABSTRAÇÃO NO ACESSO AOS DADOS
public Customer save(Customer customer) {
return customerRepository.save(customer);
}
public List<Customer> findAll() {
return customerRepository.findAll();
}
public Page<Customer> findPaginable(int page, int size) {
final Sort sort = new Sort(Sort.Direction.DESC, "name");
return customerRepository.findAll(
new PageRequest(page, size, sort));
}

22. ABSTRAÇÃO NO ACESSO AOS DADOS
Bill findByCustomerIdAndIdentifierAndYearMonth(Long customerId,
String identifier, YearMonth yearMonth);
Hibernate: select bill… from bill bill0_ where bill0_.customer_id=? and bill0_.identifier=? and
bill0_.year_month=?
@Modifying
@Query("delete from BillItem where bill.id = :#{#billId}")
void deleteByBillItem(@Param("billId") Long billId);
Hibernate: delete from bill where id=?

23. ABSTRAÇÃO NO ACESSO AOS DADOS
‣ Integração com QueryDSL
public interface BillRepository extends JpaRepository<Bill, Long>,
QueryDslPredicateExecutor<Bill> {
public Page<Bill> search(BillSearchTO searchTO) {
return billRepository.findAll(searchTO.toPredicate(),
new PageRequest(searchTO.getPage(), searchTO.getSize(),
new Sort(Sort.Direction.DESC, "id")));
}
public class BillSearchTO {
public BooleanBuilder toPredicate() {
final QBill qBill = QBill.bill;
final BooleanBuilder predicate = new BooleanBuilder();
if(!Strings.isNullOrEmpty(identifier)) {
predicate.and(qBill.identifier.eq(identifier));
}

24. ACESSO AOS DADOS
‣ Repositorios customizados
public interface BillRepositoryCustom {
Page<BillDTO> findAll(BillSearchTO searchTO);
}
public class BillRepositoryImpl implements BillRepositoryCustom {
@PersistenceContext
private EntityManager entityManager;
@Override
public Page<BillDTO> findAll(BillSearchTO searchTO) {
final JPQLQuery jpaQuery = new JPAQuery(entityManager)
.from(qBill)
.join(qBill.carrier).fetchJoin()
.join(qBill.customer).fetchJoin()
.join(qBill.items).fetchJoin();
...

25. ACESSO AOS DADOS
‣ Repositorios customizados
public interface BillRepository extends JpaRepository<Bill, Long>,
QueryDslPredicateExecutor<Bill>, BillRepositoryCustom {
...

26. SUPORTE A DIFERENTE FONTES DE DADOS
‣ Módulos Spring
‣ Módulos da comunidade
JPA LDAP
REST

27. SUPORTE A DIFERENTE FONTES DE DADOS
public interface BillFileRepository extends MongoRepository<BillFile, String> {
}
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
@Document(collection = "bill_file")
@Getter
public class BillFile {
@Id
private String id;
private String date;
private String content

28. CACHE
‣ JSR-107
‣ Caffeine
‣ Guava cache
‣ EhCache
‣ GemFire
@SpringBootApplication
@EnableCaching
public class AppConfig {
@Cacheable("carriers")
public List<Carrier> findAll() {
return carrierRepository.findAll();
}

29. https://github.com/emmanuelneri/productivity-with-spring
OBRIGADO!
emmanuelnerisouza@gmail.com
https://github.com/emmanuelneri
@emmanuelnerii
www.emmanuelneri.com.br