Spring RSocket Validation / Error Handling

* RSocket treats app exceptions as an ApplicationErrorException(string message)

* Raising error signal will end response

* Prefer

    - defaultIfEmpty

    - switchIfEmpty

    - onErrorReturn

* Send exception/error details as Item response

* @MessageExceptionHandler 

Spring RSocket API Model

RSocket	Request : Response	Input Type	Output Tpye
Request & Response	1:1	Mono<T>	Mono<R>
Fire & Forget	1:0	Mono<T>	Mono<Void>
Request Stream	1:N	Mono<T>	Flux<R>
Request Channel	M:N	Flux<T>	Flux<R>

Routing

@MessageMapping("create.user")

public Mono<User> createUser(Mono<User> usermono){

    return this.userService.create(usermono);

}

@MessageMapping("update,user")

public Mono<User> updateUser(Mono<User> usermono){

    return this.userService.update(usermono);

}

RSocketRequester W/O Data

rSocketRequester.route("product.all")

                 //.data()

                 .retrieveFlux(Product.class);

RSocket Response - Streaming vs Single List

• Streaming T
• Size - Potentially large /unknown
• Pagination
• Uber driver location updates
• Online home-delivery update
• Receiving side might take too much time to process
• File upload
• More effcient than multiple Request & Response calls

• Single List<T>
• Size is small & Data already in hand!
• More efficient than streaming response

RSocket -> Peer-to-Peer

 

SocketAcceptor

RSocket API Model

RSocket	Request : Response	HTTP
Request & Response	1:1	YES
Fire & Forget	1:0	NO
Request Stream	1:N	NO
Request Channel	M:N	NO

RSocket

- RSocket is a binary protocol for client/server application - peer-to-peer messaging - Supports Reactive-Streams * Aync * Non-blocking * BackPressure support - Supports * TCP * WebSockets * Aeron(UDP) - Developed by Netflix - Supports other languages like js, go, py, kotlin etc

Spring Boot Annotaions

@RunWith(SpringRunner.class)	Run test with Spring Context.

@SpringBootTest			Search for Spring Boot Application for configuration.

@TestConfiguration		Specify a Spring configuration for your test.

@MockBean			Injects Mockito Mock

@SpyBean			Injects Mockito Spy

@JsonTest			Creates a Jackson or Gson object mapper via Spring Boot.

@WebMvcTest			Used to test web context without a full http server.

@DataJpaTest			Used to test data layer with embedded database.

@TestPropertySource		Configure the property sources for the test.

@DirtiesContext			Resets the Spring Context after the test(expensive to do).

@WebAppConfiguration		Indicates Spring should use a Web Application context.

@TestExecutionListeners		Allows you to specify listeners for testing events.

@Transactional			Run test in transaction, rollback when complete by default.

@BeforeTranasaction		Action to run before starting a transaction.

@AfterTransaction		Action to run after a transaction.

@Commit				Specifies the transaction should be committed after the test.

@Rollback			Transaction should be rolled back after test.(Default action)

@Sql				Specify SQL scripts to run before.

@SqlConfig			Define meta data for SQL scripts.

@SqlGroup			Group fo @Sql annotations.

@Repeat				Repeat test x number of times.

@Timed 				Similar to JUnit's timeout, but will wait for test to complete, unlike JUnit.

@IfProfileValue			Indicates test is enabled for a specific testing environment.

@ProfileValueSourceConfiguration Specify a profile value source.

                                 

JUnit 4 Annotations

@Test		Identifies a method as a test method.

@Before		Executed before each test. It is used to prepare the test environment
		(e.g. read input data, initialize the class).

@After		Executed after test. It is used to cleanup the test environment. 
		It can also save memory by cleaning up expensive memory structures.

@BeforeClass	Executed once, before the start of all tests. Methods marked with
		this annotaion need to be defined as static to work with JUnit.

@AfterClass	Executed once, after all tests have been finished. 
		Methods annotated with this annotation need to be defined as static 
        	to work with JUnit.

@Ignore		Marks that the test should be disabled.

@Test(expected =	Fails if the method does not throw the named exception.
Exception.class)

@Test(timeout = 10)	Fails if the method takes longer than 100 millseconds.