Java Code Examples for reactor.core.publisher.Flux#blockFirst()

@Test
public void reusesUntilConnectionFactoryIsClosed() {
    String url = "r2dbc:tc:postgresql:///db?TC_IMAGE_TAG=10-alpine";
    ConnectionFactory connectionFactory = ConnectionFactories.get(url);

    Integer updated = Flux
        .usingWhen(
            connectionFactory.create(),
            connection -> {
                return Mono
                    .from(connection.createStatement("CREATE TABLE test(id integer PRIMARY KEY)").execute())
                    .thenMany(connection.createStatement("INSERT INTO test(id) VALUES(123)").execute())
                    .flatMap(Result::getRowsUpdated);
            },
            Connection::close
        )
        .blockFirst();

    assertThat(updated).isEqualTo(1);

    Flux<Long> select = Flux
        .usingWhen(
            Flux.defer(connectionFactory::create),
            connection -> {
                return Flux
                    .from(connection.createStatement("SELECT COUNT(*) FROM test").execute())
                    .flatMap(it -> it.map((row, meta) -> (Long) row.get(0)));
            },
            Connection::close
        );

    Long rows = select.blockFirst();

    assertThat(rows).isEqualTo(1);

    close(connectionFactory);

    Assertions
        .assertThatThrownBy(select::blockFirst)
        .isInstanceOf(PostgresqlException.class)
        // relation "X" does not exists
        // https://github.com/postgres/postgres/blob/REL_10_0/src/backend/utils/errcodes.txt#L349
        .returns("42P01", e -> ((PostgresqlException) e).getErrorDetails().getCode());
}
 

@SuppressWarnings("unchecked")
@Test
public void testCreatingAFluxWithFailure() {
    Flux<Integer> flux = Multi.createFrom().<Integer> failure(new IOException("boom")).convert()
            .with(MultiReactorConverters.toFlux());
    assertThat(flux).isNotNull();
    try {
        flux.blockFirst();
        fail("Exception expected");
    } catch (Exception e) {
        assertThat(e).isInstanceOf(RuntimeException.class).hasCauseInstanceOf(IOException.class);
    }
}
 

@Test
public void testCreatingAFluxWithFailure() {
    Flux<Integer> flux = Uni.createFrom().<Integer> failure(new IOException("boom")).convert()
            .with(UniReactorConverters.toFlux());
    assertThat(flux).isNotNull();
    try {
        flux.blockFirst();
        fail("Exception expected");
    } catch (Exception e) {
        assertThat(e).isInstanceOf(RuntimeException.class).hasCauseInstanceOf(IOException.class);
    }
}
 

@Override
public Mono<Boolean> decide(Authentication authentication, ServerWebExchange object, Flux<ConfigAttribute> configAttributes) {
	ConfigAttribute attribute = configAttributes.blockFirst();
	EvaluationContext context = handler.createEvaluationContext(authentication, object);
	Expression expression = handler.getExpressionParser().parseExpression(attribute.getAttribute());
	return Mono.just(ExpressionUtils.evaluateAsBoolean(expression, context));
}
 

@Test
public void functionApp() {
	this.initializer = new AbstractSpringFunctionAdapterInitializer<Object>(FluxFunctionApp.class) {

	};
	this.initializer.initialize(null);
	Flux<?> result = Flux.from(this.initializer.apply(Flux.just(new Foo())));
	Object o = result.blockFirst();
	assertThat(result.blockFirst()).isInstanceOf(Bar.class);
}
 

@Test
public void shouldReturnNewSpanFromTraceContext() {
	Flux<Long> flux = this.testBean.newSpanInTraceContext();
	Long newSpanId = flux.blockFirst();

	Awaitility.await().untilAsserted(() -> {
		then(this.spans).hasSize(1);
		then(this.spans.get(0).name()).isEqualTo("span-in-trace-context");
		then(this.spans.get(0).id()).isEqualTo(toHexString(newSpanId));
		then(this.tracer.currentSpan()).isNull();
	});
}
 

@Test
public void shouldReturnNewSpanFromSubscriberContext() {
	Flux<Long> flux = this.testBean.newSpanInSubscriberContext();
	Long newSpanId = flux.blockFirst();

	Awaitility.await().untilAsserted(() -> {
		then(this.spans).hasSize(1);
		then(this.spans.get(0).name()).isEqualTo("span-in-subscriber-context");
		then(this.spans.get(0).id()).isEqualTo(toHexString(newSpanId));
		then(this.tracer.currentSpan()).isNull();
	});
}
 

@Override
protected String getOne(Flux instance) {
    return (String) instance.blockFirst();
}
 

@Override
protected String getOne(Flux instance) {
    return (String) instance.blockFirst();
}