SseEventSink.send() should throw ISE after eventSink has been closed

Change-Id: I6921d6d01a90043f80120d9d1ab988b4d3a58ea1

Author: Adam Lindenthal

media/sse/src/main/java/org/glassfish/jersey/media/sse/internal/JerseyEventSink.java

@@ -114,6 +114,7 @@ public void close() {
 
     @Override
     public CompletionStage<?> send(OutboundSseEvent event) {
+        checkClosed();
         try {
             this.write(event);
             return CompletableFuture.completedFuture(null);

media/sse/src/test/java/org/glassfish/jersey/media/sse/internal/JerseyEventSinkTest.java

@@ -87,4 +87,13 @@ public void onComplete() throws Exception {
         thrown.expect(IllegalStateException.class);
         eventSink.onComplete();
     }
+
+    @Test
+    public void test() throws Exception {
+        JerseyEventSink eventSink = new JerseyEventSink();
+
+        eventSink.close();
+        thrown.expect(IllegalStateException.class);
+        eventSink.send(null);
+    }
 }