ISSUE-46: fix notification SSE buffering

server/skillhub-app/src/main/java/com/iflytek/skillhub/filter/RequestLoggingFilter.java

@@ -8,6 +8,8 @@
 import org.slf4j.LoggerFactory;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.stereotype.Component;
 import org.springframework.web.filter.OncePerRequestFilter;
 import org.springframework.web.util.ContentCachingRequestWrapper;
@@ -40,6 +42,11 @@ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse
             filterChain.doFilter(request, response);
             return;
         }
+        if (isNotificationSse(uri)) {
+            prepareSseResponse(response);
+            filterChain.doFilter(request, response);
+            return;
+        }
 
         ContentCachingRequestWrapper cachedRequest = new ContentCachingRequestWrapper(request);
         ContentCachingResponseWrapper cachedResponse = new ContentCachingResponseWrapper(response);
@@ -92,6 +99,16 @@ private boolean shouldSkip(String uri) {
         return false;
     }
 
+    private boolean isNotificationSse(String uri) {
+        return uri != null && uri.endsWith("/notifications/sse");
+    }
+
+    private void prepareSseResponse(HttpServletResponse response) {
+        response.setContentType(MediaType.TEXT_EVENT_STREAM_VALUE);
+        response.setHeader(HttpHeaders.CACHE_CONTROL, "no-cache, no-transform");
+        response.setHeader("X-Accel-Buffering", "no");
+    }
+
     private String getRequestBody(ContentCachingRequestWrapper request) {
         byte[] buf = request.getContentAsByteArray();
         if (buf.length > 0) {

server/skillhub-app/src/test/java/com/iflytek/skillhub/filter/RequestLoggingFilterTest.java

@@ -1,22 +1,26 @@
 package com.iflytek.skillhub.filter;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.Logger;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.read.ListAppender;
 import jakarta.servlet.FilterChain;
 import jakarta.servlet.ServletException;
+import jakarta.servlet.ServletResponse;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
-
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.util.List;
-
-import static org.assertj.core.api.Assertions.assertThat;
+import org.springframework.web.util.ContentCachingResponseWrapper;
 
 class RequestLoggingFilterTest {
 
@@ -101,6 +105,44 @@ void doFilterInternal_logsCoreSummaryFields()
         assertThat(loggedMessages()).noneMatch(message -> message.contains("Headers: {"));
     }
 
+    @Test
+    void doFilterInternal_shouldBypassCachingWrapperForNotificationSse() throws Exception {
+        RequestLoggingFilter filter = new RequestLoggingFilter();
+        MockHttpServletRequest request = new MockHttpServletRequest("GET", "/api/web/notifications/sse");
+        MockHttpServletResponse response = new MockHttpServletResponse();
+        AtomicReference<ServletResponse> responseSeenByChain = new AtomicReference<>();
+        FilterChain chain = (servletRequest, servletResponse) -> {
+            responseSeenByChain.set(servletResponse);
+            servletResponse.getWriter().write("event: connected\n");
+            servletResponse.flushBuffer();
+        };
+
+        filter.doFilter(request, response, chain);
+
+        assertThat(responseSeenByChain.get()).isSameAs(response);
+        assertThat(response.getHeader("X-Accel-Buffering")).isEqualTo("no");
+        assertThat(response.getHeader(HttpHeaders.CACHE_CONTROL)).isEqualTo("no-cache, no-transform");
+        assertThat(response.getContentType()).isEqualTo(MediaType.TEXT_EVENT_STREAM_VALUE);
+        assertThat(response.getContentAsString()).contains("event: connected");
+    }
+
+    @Test
+    void doFilterInternal_shouldKeepCachingWrapperForRegularApiResponses() throws Exception {
+        RequestLoggingFilter filter = new RequestLoggingFilter();
+        MockHttpServletRequest request = new MockHttpServletRequest("GET", "/api/web/notifications/unread-count");
+        MockHttpServletResponse response = new MockHttpServletResponse();
+        AtomicReference<ServletResponse> responseSeenByChain = new AtomicReference<>();
+        FilterChain chain = (servletRequest, servletResponse) -> {
+            responseSeenByChain.set(servletResponse);
+            servletResponse.getWriter().write("{\"count\":1}");
+        };
+
+        filter.doFilter(request, response, chain);
+
+        assertThat(responseSeenByChain.get()).isInstanceOf(ContentCachingResponseWrapper.class);
+        assertThat(response.getContentAsString()).isEqualTo("{\"count\":1}");
+    }
+
     private void attachAppender() {
         logger.setLevel(Level.INFO);
         appender = new ListAppender<>();