我正在使用Spring Webflux，据我所知，通过使用它，用于接收请求和响应的线程应该是不同的。然而，无论我使用netty还是undertow，最终都会使用相同的线程。
我的应用程序是一个简单的MySQL DB crud应用程序。我没有使用r2dbc，而是使用与Executor和Scheduler耦合的jdbc。
如下日志所示，请求由线程[XNIO-1 I/O-6]处理，响应由同一线程给出。 因此，我假设该线程在等待db操作完成时被阻塞了。我该如何解决这个问题？
以下是日志：
2019-07-23 17:49:10.051 INFO 132 --- [ main] org.xnio : XNIO version 3.3.8.Final
2019-07-23 17:49:10.059 INFO 132 --- [ main] org.xnio.nio : XNIO NIO Implementation Version 3.3.8.Final
2019-07-23 17:49:10.114 INFO 132 --- [ main] o.s.b.w.e.undertow.UndertowWebServer : Undertow started on port(s) 8080 (http)
2019-07-23 17:49:10.116 INFO 132 --- [ main] c.n.webflux.demo.WebfluxFunctionalApp : Started WebfluxFunctionalApp in 1.262 seconds (JVM running for 2.668)
2019-07-23 17:49:10.302 DEBUG 132 --- [ XNIO-1 I/O-6] o.s.w.s.adapter.HttpWebHandlerAdapter : [4c85975] HTTP GET "/api/findall"
2019-07-23 17:49:10.322 DEBUG 132 --- [ XNIO-1 I/O-6] s.w.r.r.m.a.RequestMappingHandlerMapping : [4c85975] Mapped to public reactor.core.publisher.Mono<java.util.List<com.webflux.demo.model.TypeStatus>> com.webflux.demo.controller.MonitoringController.findAll()
2019-07-23 17:49:10.337 DEBUG 132 --- [ XNIO-1 I/O-6] o.s.w.r.r.m.a.ResponseBodyResultHandler : Using 'application/json;charset=UTF-8' given [*/*] and supported [application/json;charset=UTF-8, application/*+json;charset=UTF-8, text/event-stream]
2019-07-23 17:49:10.338 DEBUG 132 --- [ XNIO-1 I/O-6] o.s.w.r.r.m.a.ResponseBodyResultHandler : [4c85975] 0..1 [java.util.List<com.webflux.demo.model.TypeStatus>]
2019-07-23 17:49:10.347 INFO 132 --- [pool-1-thread-1] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2019-07-23 17:49:10.785 INFO 132 --- [pool-1-thread-1] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2019-07-23 17:49:10.838 DEBUG 132 --- [pool-1-thread-1] org.springframework.web.HttpLogging : [4c85975] Encoding [[com.webflux.demo.model.TypeStatus@7b4509cb, com.webflux.demo.model.TypeStatus@22676ebe, (truncated)...]
2019-07-23 17:49:10.949 DEBUG 132 --- [ XNIO-1 I/O-6] o.s.w.s.adapter.HttpWebHandlerAdapter : [4c85975] Completed 200 OK
同时我的dao是
@Repository
public class TypeStatusJdbcTemplate {
private JdbcTemplate jdbcTemplate;
public TypeStatusJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
private final static String SQL_FIND_ALL = "select * from `monitoring`.`type_status` limit 3";
public List<TypeStatus> findAll() {
return jdbcTemplate.query(SQL_FIND_ALL,
new TypeStatusMapper());
}
}
服务是
@Service
public class MonitoringService {
private final Scheduler scheduler;
private TypeStatusJdbcTemplate repository;
public MonitoringService(Scheduler scheduler, TypeStatusJdbcTemplate repository) {
this.scheduler = scheduler;
this.repository = repository;
}
public Mono<List<TypeStatus>> findAll() {
return Mono.fromCallable(repository::findAll).subscribeOn(scheduler);
}
}
控制器是
@RestController
@RequestMapping("/api")
public class MonitoringController {
private final MonitoringService monitoringService;
private static final Logger logger = LoggerFactory.getLogger(MonitoringController.class);
public MonitoringController(MonitoringService monitoringService) {
this.monitoringService = monitoringService;
}
@GetMapping(value="/findall")
public Mono<List<TypeStatus>> findAll() {
return monitoringService.findAll();
}
}
主文件（显示调度程序）
@SpringBootApplication
public class WebfluxFunctionalApp {
public static void main(String[] args){
SpringApplication.run(WebfluxFunctionalApp.class, args);
}
@PostConstruct
public void init(){
// Setting Spring Boot SetTimeZone
TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
}
@Bean
public Scheduler jdbcScheduler() {
return Schedulers.fromExecutor(Executors.newFixedThreadPool(30));
}
}
subscribeOn，所有阻塞数据库工作都被委托给另一个线程，这就是为什么XNIO-1 I/O-6不会被阻塞的原因。除非您没有自动装配Netty调度程序 ;) - arapMono.fromCallable(()->{})块中放置类似于System.out.println("callable thread: "+Thread.currentThread().getName());的内容。您将看到类似于callable thread: pool-1-thread-1的东西。它显示请求是由XNIO-1线程处理的，然后将控制传递给线程池中的线程，当响应准备就绪时，它将被传回到NIO-1。我认为这基本上回答了您的问题 - XNIO-1没有被阻塞，因为所有阻塞工作都在另一个线程上执行，而XNIO-1仅用于处理请求和响应。 - arap