我正在尝试使用Spring 4(tomcat 7,servlet-api 3.0.1)创建服务器发送的事件。
问题是我的Events
在调用方法发送后没有立即发送。只有在SseEmitter
超时后,它们才会同时(具有相同的时间戳)到达客户端,并出现EventSource
的错误事件。然后客户端正在尝试重新连接。知道发生了什么吗?
我创建了一个简单的服务:
@RequestMapping(value = "subscribe", method = RequestMethod.GET)
public SseEmitter subscribe () throws IOException {
final SseEmitter emitter = new SseEmitter();
Executors.newScheduledThreadPool(1).scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
try {
emitter.send(SseEmitter.event().data("Thread writing: " + Thread.currentThread()).name("ping"));
} catch (Exception e) {
}
}
} , 1000, 1000, TimeUnit.MILLISECONDS);
return emitter;
}
使用客户端代码:
sse = new EventSource(urlBuilder(base, url));
sse.addEventListener('ping', function (event) {
dfd.notify(event);
});
sse.addEventListener('message', function(event){
dfd.notify(event);
});
sse.addEventListener('close', function(event){
dfd.notify(event);
});
sse.onerror = function (error) {
console.log(error);
};
sse.onmessage = function (event){
dfd.notify(event);
};
App initalizer代码
public class WebAppInitializer implements WebApplicationInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
ctx.register(AppConfig.class);
ctx.setServletContext(servletContext);
ctx.refresh();
ServletRegistration.Dynamic dynamic = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));
dynamic.setAsyncSupported(true);
dynamic.addMapping("/api/*");
dynamic.setLoadOnStartup(1);
dynamic.setMultipartConfig(ctx.getBean(MultipartConfigElement.class));
javax.servlet.FilterRegistration.Dynamic filter = servletContext
.addFilter("StatelessAuthenticationFilter",
ctx.getBean("statelessAuthenticationFilter", StatelessAuthenticationFilter.class));
filter.setAsyncSupported(true);
filter.addMappingForUrlPatterns(null, false, "/api/*");
filter = servletContext.addFilter("HibernateSessionRequestFilter",
ctx.getBean("hibernateSessionRequestFilter", HibernateSessionRequestFilter.class));
filter.setAsyncSupported(true);
filter.addMappingForUrlPatterns(null, false, "/api/user/*");
}
}
AppConfig.java
@Configuration
@ComponentScan("ru.esoft.workflow")
@EnableWebMvc
@PropertySource({"classpath:mail.properties", "classpath:fatclient.properties"})
@EnableAsync
@EnableScheduling
public class AppConfig extends WebMvcConfigurerAdapter {
...
}
答案 0 :(得分:3)
我在测试SSEEmitters时遇到了这个问题。从我在线阅读的所有内容中,SSEEmitters旨在与Reactive Streams的某些实现结合使用,例如RxJava。它有点复杂,但绝对有效。我们的想法是创建发射器和Observable,并将后者订阅到Publisher。 Publisher在单独的线程中执行其行为,在输出准备就绪时通知Observable,并且observable触发emitter.send。以下是一个示例代码段,可以执行您想要的操作:
priv/static/.well-known/acme-challenge/(some-unique-string)
以下是相应的发布商:
@RequestMapping("/whatever")
public SseEmitter index(
SseEmitter emitter = new SseEmitter();
Publisher<String> responsePublisher = someResponseGenerator.getPublisher();
Observable<String> responseObservable = RxReactiveStreams.toObservable(responsePublisher);
responseObservable.subscribe(
str -> {
try {
emitter.send(str);
} catch (IOException ex) {
emitter.completeWithError(ex);
}
},
error -> {
emitter.completeWithError(error);
},
emitter::complete
);
return emitter;
};
此模型有一些在线here和here的示例,您可以通过Google搜索RxJava SseEmitter找到更多信息。&#39; RxJava SseEmitter&#39;需要一些时间才能完成Reactive Streams / RxJava / SseEmitter交互,但是一旦你这样做就非常优雅了。希望这能让你走上正确的道路!
答案 1 :(得分:0)
虽然另一个答案是正确的,但如果您想自己管理,可以致电:
emitter.complete()