Spring 4.0 has been released on December 2013. If you want to review some of the Core and Web container improvements, check this out.

1. Subtitle Text
Author
Contact info
David Gómez
@dgomezg

2. Spring 4
core improvements

3. Spring 4 core improvements
Generics in Qualifiers
Exposing attributes in Meta-annotations
Autowiring Lists and Arrays
@Description on @Configuration classes
@Conditional (user-defined @Profiles)
Time Zone support on Locale Context

4. Generics in Qualifiers
En Spring 3.2….
public interface MessageService {
!
!
public String getMessage();
}
public class GeneralWaver
implements MessageService{
@Override
public String getMessage() {
return "Hello world!";
}
public class PersonWaver
implements MessageService {
!
!
!
}
@Autowired
public PersonRepository personRepository;
@Override
public String getMessage() {
...
}
}
public class MultiMessagePrinter {
!
!
!
}
//All Message Services are injected
@Autowired
private List<MessageService> messageServices;
public void printMessage() {
for (MessageService messageService: messageServices) {
System.out.println(messageService.getMessage());
}
}

5. Generics in Qualifiers
En Spring 3.2….
<?xml version="1.0" encoding="UTF-8"?>
<beans ...>
!
!
!
!
<context:annotation-config/>
<!-- Database config -->
<jdbc:embedded-database id="dataSource">
<jdbc:script location="classpath:sql/schema.ddl"/>
<jdbc:script location="classpath:sql/data.sql"/>
</jdbc:embedded-database>
<bean id=“personRepository"
class="com.autentia.playground.spring4.helloWorld.db.JdbcPersonRepository"/>
<!-- Wavers (MessageService implementations) -->
<bean id="personWaver" class="com.autentia.playground.spring4.helloWorld.messages.PersonWaver"/>
<bean id="generalWaver" class="com.autentia.playground.spring4.helloWorld.messages.GeneralWaver"/>
<!-- Printer : waves to everybody using available MessageServices -->
<bean id="messagePrinter"
class="com.autentia.playground.spring4.helloWorld.messages.MultiMessagePrinter"/>
!
</beans>

6. Generics in Qualifiers
En Spring 4 also….
public interface MessageService<T> {
!
!
public T getMessage();
}
public class GeneralWaver
implements MessageService<String>{
@Override
public String getMessage() {
return "Hello world!";
}
public class PersonWaver
implements MessageService<Person> {
!
!
!
}
@Autowired
public PersonRepository personRepository;
@Override
public Person getMessage() {
...
}
}
public class MultiMessagePrinter {
!
!
!
}
@Autowired
private MessageService<Person> messageServices;
public void printMessage() {
System.out.println(messageService.getMessage().toString());
}

7. Autowiring ordered Lists and Arrays
In Spring 3.2….
public interface MessageService {
!
!
public String getMessage();
}
public class GeneralWaver
implements MessageService{
@Override
public String getMessage() {
return "Hello world!";
}
public class PersonWaver
implements MessageService {
!
!
!
}
@Autowired
public PersonRepository personRepository;
@Override
public String getMessage() {
...
}
}
public class MultiMessagePrinter {
!
!
!
}
//All Message Services are injected
@Autowired
private List<MessageService> messageServices;
public void printMessage() {
for (MessageService messageService: messageServices) {
System.out.println(messageService.getMessage());
}
Hello Sr. David Gomez G.
}
Hello world!

8. Autowiring ordered Lists and Arrays
In Spring 4….
public interface MessageService {
!
!
public String getMessage();
public class GeneralWaver }
implements MessageService, Ordered {
!
!
!
}
@Override
public String getMessage() {
return "Hello world!";
}
@Override
public int getOrder() {
return Integer.MIN_VALUE;
}
public class MultiMessagePrinter {
!
!
!
}
public class PersonWaver
implements MessageService {
!
!
@Autowired
public PersonRepository personRepository;
@Override
public int getOrder() {
return 0;
}
}
//All Message Services are injected
@Autowired
private List<MessageService> messageServices;
public void printMessage() {
for (MessageService messageService: messageServices) {
System.out.println(messageService.getMessage());
}
Hello world!
}
Hello Sr. David Gomez G.

9. Exposing attributes in Meta-annotations
In Spring 3.2….
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface Service {
String[] value();
}
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Service
@Transactional(timeout=60)
public @interface MyTransactionalService {
String[] value();
}
@MyTransactionalService
public class PersonWaver
implements MessageService {
!
!
}
@Autowired
public PersonRepository personRepository;
@Override
public String getMessage() {
...
}

10. Exposing attributes in Meta-annotations
In Spring 4….
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Service
@Transactional
public @interface MyTransactionalService {
String[] value();
Propagation propagation() default Propagation.REQUIRED;
int timeout() default TransactionDefinition.TIMEOUT_DEFAULT;
!
}
@MyTransactionalService(propagation=Propagation.REQUIRES_NEW)
public class PersonWaver
implements MessageService {
!
!
}
@Autowired
public PersonRepository personRepository;
@Override
public String getMessage() {
...
}

11. @Description on @Configuration classes
In Spring 4….
@Configuration
@ComponentScan
public class Application {
!
@Bean
@Description("This is a mock implementation of MockService")
MessageService mockMessageService() {
return new MessageService() {
@Override
public String getMessage() {
return "Hello world!";
}
};
}
}
Useful when beans are exposed, !
for example, as JMX beans

12. @Profiles and @Conditional
In Spring 3.2….
!
<beans profile="dev">
<jdbc:embedded-database id="dataSource">
<jdbc:script location="classpath:sql/schema.ddl"/>
<jdbc:script location="classpath:sql/data.sql"/>
</jdbc:embedded-database>
</beans>
<beans profile="prod">
<jee:jndi-lookup id="dataSource" jndi-name="jdbc/LiveDataSource"/>
</beans>
-Dspring.profiles.active=“dev"
@Configuration
@ComponentScan
@Profile(“test”)
public class Application {
!
}
@Bean
@Description("This is a mock implementation of MockService")
MessageService mockMessageService() {
return new MessageService() {
@Override
public String getMessage() {
return "Hello world!";
}
};
}

13. @Profiles and @Conditional
In Spring 4….
@Configuration
@ComponentScan
public class Application {
!
@Bean
@Description("This is a mock implementation of MockService”)
@Conditional(NoMessageServiceDefined.class)
MessageService mockMessageService() {
return new MessageService() {
@Override
public String getMessage() {
return "Hello world!";
}
};
}
}
!
public class NoMessageServiceDefined implements Condition {
!
}
@Override
public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
return context.getBeanFactory().getBeansOfType(MessageService.class)
.isEmpty();
}

14. Web Container
improvements

15. Spring 4 web improvements
Support for Servlet 3.0
(Servlet 2.5 still supported for GAE compatibility)
(servlet 3.0 jar needed for SPRING MVC Tests)
@RestController (@RequestMapping + @ResponseBody)
@AsyncRestTemplate (Non-blocking REST clients)
!

16. @RestController
In Spring 3.2….
@Controller
public class WaverController {
!
!
!
}
@RequestMapping("/person")
public @ResponseBody Person showPersonalMessage() {
return personWaver.getMessage();
}
@RequestMapping("/message")
public @ResponseBody String showMessage() {
return genericWaver.getMessage();
}

17. @RestController
In Spring 4…
@RestController = @Controller + @ResponseBody
@RestController
public class WaverController {
!
!
!
}
@RequestMapping("/person")
public Person showPersonalMessage() {
return personWaver.getMessage();
}
@RequestMapping("/message")
public String showMessage() {
return genericWaver.getMessage();
}

18. @AsyncRestTemplate (Non-blocking REST clients)
RestTemplate
public class RestTemplate {
public <T> T getForObject(String url, Class<T> responseType, Object... urlVariables) {}
public <T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Object...
urlVariables) {}
public <T> T postForObject(String url, Object request, Class<T> responseType, Object...
uriVariables) {}
public void put(String url, Object request, Object... urlVariables) {}
}
public class RestTemplate {
public <T> T getForObject(String url, Class<T> responseType, Object... urlVariables) {}
public <T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Object...
urlVariables) {}
public <T> T postForObject(String url, Object request, Class<T> responseType, Object...
uriVariables) {}
public void put(String url, Object request, Object... urlVariables) {}
}

19. @AsyncRestTemplate (Non-blocking REST clients)
AsyncRestTemplate
public class AsyncRestTemplate {
!
public <T> ListenableFuture<ResponseEntity<T>>
getForEntity(String url, Class<T> responseType, Object... uriVariables) {}
public ListenableFuture<URI>
postForLocation(String url, HttpEntity<?> request, Object... uriVariables) {}
}
public ListenableFuture<?>
put(String url, HttpEntity<?> request, Object... uriVariables) {}
!
!
public interface ListenableFuture<T> extends Future<T> {
!
!
}
void addCallback(ListenableFutureCallback<? super T> callback);

20. @AsyncRestTemplate (Non-blocking REST clients)
AsyncRestTemplate
ListenableFuture<ResponseEntity<Person>> futureEntity = template.getForEntity(
"http://localhost:8080/spring4/person/{personId}", Integer.class, 1);
!
// register a callback
futureEntity.addCallback(new ListenableFutureCallback<ResponseEntity<Person>>() {
@Override
public void onSuccess(ResponseEntity<Person> entity) {
//...
}
!
});
@Override
public void onFailure(Throwable t) {
//...
}

21. Spring 4
meets
Java 8

22. Support for lambdas on callbacks
In Spring 3.2
public Person findById(int id) {
return jdbcTemplate.query("select * from persons where id = ?",
new RowMapper<Person>() {
@Override
public Person mapRow(ResultSet rs, int rowNum) throws SQLException {
return new Person(rs.getInt("id"),
rs.getString("treatment"),
rs.getString("name"),
rs.getString("surname"),
new Date(rs.getDate("birthDate").getTime()));
}
},
id)
.get(0);
}

23. Support for lambdas on callbacks
In Spring 4
public Person findById(int id) {
return jdbcTemplate.queryForObject(
"select * from persons where id = ?",
(rs, rowNum) -> new Person(rs.getInt("id"),
rs.getString("treatment"),
rs.getString("name"),
rs.getString("surname"),
new Date(rs.getDate("birthDate").getTime())),
id);
}

24. Support for lambdas on callbacks
In Spring 4
@Override
@Transactional
public Person getMessage() {
final Person person;
!
!
}
txTemplate.execute((txStatus) -> {
person = messageRepository.findById(1);
txStatus.setRollbackOnly();
return null;
});
return person;

25. JSR-310
package java.time
Distinction between Computer-times and Human-Times
Human-Times
TimeZone (ISO-8601)
LocalDateTime
LocalDate
LocalTime

26. JSR-310
package java.time
Amounts of Time
Duration (nanosecond resolution)
Amounts of Days
Period (years, months, and days)
TimeZones
ZonedDateTime
OffsetDateTime

27. JSR-310 in Spring 4
In web handler Methods
import java.time.Clock;
import java.time.ZoneId;
!
@RestController
public class WaverController {
!
!
}
@RequestMapping("/person")
public Person showPersonalMessage(ZoneId zoneId) {
Clock clock = Clock.of(zoneId)
LocalTime time = LocalTime.now(clock);
return personWaver.getMessageFor(time);
}

28. External Libraries

29. External Libraries Support
Hibernate 3.6+
Hibernate 4.3 (JPA 2.1)
EhCache 2.1
Quartz 1.8
JodaTime 2.0
Hibernate Validator 4.3 (Bean Validation 1.1)
Jackson 2.0 (1.8/1.9 deprecated)

30. Other changes

31. Support for JEE7 (& JEE6)
Serlvet 3.0
JMS 2.0
JTA 1.2
JPA 2.1
Bean Validation 1.1
JSR-236 Concurrency (ThreadExecutors)

32. WebSockets
with
Spring 4

33. WebSocket Support
WebSocket server support via JSR-356 runtimes
(Tomcat 7.0.7 -Jetty 9)
Fallback option using SockJS
(SockJsHttpRequestHandler)
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34. (de momento)
Subtitle Text
Author
Contact info
David Gómez
@dgomezg