Addressing comments.

provider/notification-azure/src/main/java/org/opengroup/osdu/notification/provider/azure/util/HandshakeFilter.java

@@ -57,6 +57,7 @@ public class HandshakeFilter implements Filter {
 
             String handshakeResponse = this.handshakeHandler.getHandshakeResponse();
             PrintWriter out = httpServletResponse.getWriter();
+            out.flush();
             out.print(handshakeResponse);
             return;
         }

provider/notification-azure/src/test/java/org/opengroup/osdu/notification/provider/azure/util/HandshakeFilterTest.java

@@ -20,13 +20,16 @@ import org.junit.runner.RunWith;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnitRunner;
+import org.opengroup.osdu.notification.provider.interfaces.IPubsubHandshakeHandler;
 import org.opengroup.osdu.notification.provider.interfaces.IPubsubRequestBodyExtractor;
 
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import java.io.PrintWriter;
 
 import static org.mockito.Mockito.*;
 
@@ -37,15 +40,24 @@ public class HandshakeFilterTest {
     @Mock
     private IPubsubRequestBodyExtractor requestBodyExtractor;
 
+    @Mock
+    private IPubsubHandshakeHandler handshakeHandler;
+
     @Mock
     private HttpServletRequest httpServletRequest;
 
+    @Mock
+    private HttpServletResponse httpServletResponse;
+
     @Mock
     private ServletResponse servletResponse;
 
     @Mock
     private FilterChain filterChain;
 
+    @Mock
+    private PrintWriter printWriter;
+
     @InjectMocks
     private HandshakeFilter sut;
 
@@ -58,4 +70,16 @@ public class HandshakeFilterTest {
 
         verify(this.filterChain, times(1)).doFilter(httpServletRequest, servletResponse);
     }
+
+    @Test
+    public void should_NotCallFiltersIfHandshake() throws IOException, ServletException {
+        doReturn("records-changed").when(httpServletRequest).getServletPath();
+        doReturn(true).when(this.requestBodyExtractor).isHandshakeRequest();
+        doReturn("handshake response").when(this.handshakeHandler).getHandshakeResponse();
+        doReturn(this.printWriter).when(this.httpServletResponse).getWriter();
+
+        this.sut.doFilter(this.httpServletRequest, this.httpServletResponse, this.filterChain);
+
+        verify(this.filterChain, times(0)).doFilter(httpServletRequest, servletResponse);
+    }
 }