搞乱 JAX-RS SSE：无法在 javax.ws.rs.sse.SseEventSink class 中找到合适的构造函数

Question

我目前正在尝试使用 SSE 在网络项目中进行实验。我必须更新并启用异步支持。但是，对 'subscribe' 端点的简单 'GET' 请求会引发错误，即使是通过浏览器完成的。

@Path("/subscribe")
@GET
@Produces(MediaType.SERVER_SENT_EVENTS)
public void subscribe(@Context SseEventSink eSink) {
    sinkList.add(eSink);
}

如果我只是用浏览器输入请求，这是不正确的吗？这是兼容性问题吗？与具有客户端的 websockets 相比，我还能如何测试 SSE 连接？到目前为止，我知道不能使用构造函数创建 SseEventSinks。我对此有点不知所措

如有任何帮助，我们将不胜感激！

谢谢

汇总了下面抛出的 error/warning 条日志。

WARNING: The following warnings have been detected: WARNING: HK2 service reification failed for [javax.ws.rs.sse.SseEventSink] with an exception: MultiException stack 1 of 2 java.lang.NoSuchMethodException: Could not find a suitable constructor in javax.ws.rs.sse.SseEventSink class. at org.glassfish.jersey.inject.hk2.JerseyClassAnalyzer.getConstructor(JerseyClassAnalyzer.java:192) at org.jvnet.hk2.internal.Utilities.getConstructor(Utilities.java:180) at org.jvnet.hk2.internal.ClazzCreator.initialize(ClazzCreator.java:129)

...

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748) MultiException stack 2 of 2 java.lang.IllegalArgumentException: Errors were discovered while reifying SystemDescriptor( implementation=javax.ws.rs.sse.SseEventSink contracts={javax.ws.rs.sse.SseEventSink} scope=org.glassfish.jersey.process.internal.RequestScoped qualifiers={} descriptorType=CLASS descriptorVisibility=NORMAL metadata= rank=0 loader=null proxiable=null proxyForSameScope=null analysisName=null id=198 locatorId=0 identityHashCode=282776705 reified=false) at org.jvnet.hk2.internal.SystemDescriptor.reify(SystemDescriptor.java:705) at org.jvnet.hk2.internal.ServiceLocatorImpl.reifyDescriptor(ServiceLocatorImpl.java:464)

...

WARNING: HK2 service reification failed for [javax.ws.rs.sse.SseEventSink] with an exception: MultiException stack 1 of 2 java.lang.NoSuchMethodException: Could not find a suitable constructor in javax.ws.rs.sse.SseEventSink class. at org.glassfish.jersey.inject.hk2.JerseyClassAnalyzer.getConstructor(JerseyClassAnalyzer.java:192) at org.jvnet.hk2.internal.Utilities.getConstructor(Utilities.java:180) at org.jvnet.hk2.internal.ClazzCreator.initialize(ClazzCreator.java:129)

...

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748) MultiException stack 2 of 2 java.lang.IllegalArgumentException: Errors were discovered while reifying SystemDescriptor( implementation=javax.ws.rs.sse.SseEventSink contracts={javax.ws.rs.sse.SseEventSink} scope=org.glassfish.jersey.process.internal.RequestScoped

...

SEVERE: Servlet.service() for servlet [Jersey Web Application] in context with path [/Api] threw exception [java.lang.IllegalArgumentException: SseEventSink parameter detected, but not found.] with root cause java.lang.IllegalArgumentException: SseEventSink parameter detected, but not found. at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$SseEventSinkInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:159) at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:103)

... at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748)

Answer 1

我遇到了同样的问题，通过将 jersey-media-sse 依赖项添加到我的 pom.xml（使用 Maven）

使其正常工作

<!-- https://mvnrepository.com/artifact/org.glassfish.jersey.media/jersey-media-sse -->
<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-sse</artifactId>
    <version>2.27</version>
</dependency>

如果你不使用 Maven，这里是 the link to the repo

我不确定，但据我了解，问题是 SseEventSink 是一个接口，Jersey 无法为它实例化任何 class。上面的依赖项可能为 SseEventSink 接口

提供了默认实现和默认映射器