Prevent NPE in micrometer when there is no response & 404

ext/micrometer/src/main/java/org/glassfish/jersey/micrometer/server/JerseyKeyValues.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2024 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -23,6 +23,9 @@
 import org.glassfish.jersey.server.ExtendedUriInfo;
 import org.glassfish.jersey.server.monitoring.RequestEvent;
 
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.core.Response;
+
 /**
  * Factory methods for {@link KeyValue KeyValues} associated with a request-response
  * exchange that is handled by Jersey server.
@@ -38,6 +41,9 @@ class JerseyKeyValues {
     private static final KeyValue URI_ROOT = JerseyObservationDocumentation.JerseyLegacyLowCardinalityTags.URI
         .withValue("root");
 
+    private static final KeyValue URI_UNKNOWN = JerseyObservationDocumentation.JerseyLegacyLowCardinalityTags.URI
+            .withValue("UNKNOWN");
+
     private static final KeyValue EXCEPTION_NONE = JerseyObservationDocumentation.JerseyLegacyLowCardinalityTags.EXCEPTION
         .withValue("None");
 
@@ -82,17 +88,30 @@ static KeyValue status(ContainerResponse response) {
      * @return the uri KeyValue derived from the request event
      */
     static KeyValue uri(RequestEvent event) {
-        ContainerResponse response = event.getContainerResponse();
-        if (response != null) {
-            int status = response.getStatus();
+        int status = 0;
+        if (event.getContainerResponse() != null) {
+            status = event.getContainerResponse().getStatus();
+        } else if (WebApplicationException.class.isInstance(event.getException())) {
+            Response webAppResponse = ((WebApplicationException) event.getException()).getResponse();
+            if (webAppResponse != null) {
+                status = webAppResponse.getStatus();
+            }
+        }
+        if (status != 0) {
             if (JerseyTags.isRedirection(status) && event.getUriInfo().getMatchedResourceMethod() == null) {
                 return URI_REDIRECTION;
             }
             if (status == 404 && event.getUriInfo().getMatchedResourceMethod() == null) {
                 return URI_NOT_FOUND;
             }
+            if (status >= 500 && status <= 599) {
+                return STATUS_SERVER_ERROR;
+            }
         }
         String matchingPattern = JerseyTags.getMatchingPattern(event);
+        if (matchingPattern == null) {
+            return URI_UNKNOWN;
+        }
         if (matchingPattern.equals("/")) {
             return URI_ROOT;
         }

ext/micrometer/src/test/java/org/glassfish/jersey/micrometer/server/exception/JerseyKeyValuesTest.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package org.glassfish.jersey.micrometer.server.exception;
+
+import io.micrometer.common.KeyValue;
+import io.micrometer.common.KeyValues;
+import org.glassfish.jersey.micrometer.server.DefaultJerseyObservationConvention;
+import org.glassfish.jersey.micrometer.server.JerseyContext;
+import org.glassfish.jersey.server.ExtendedUriInfo;
+import org.glassfish.jersey.server.internal.monitoring.RequestEventImpl;
+import org.glassfish.jersey.server.monitoring.RequestEvent;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+
+import javax.ws.rs.NotFoundException;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.Collections;
+import java.util.Optional;
+
+public class JerseyKeyValuesTest {
+    @Test
+    public void testOnException() {
+        ExtendedUriInfo uriInfo = (ExtendedUriInfo) Proxy.newProxyInstance(getClass().getClassLoader(),
+                new Class[]{ExtendedUriInfo.class},
+                new InvocationHandler() {
+            @Override
+            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+                switch (method.getName()) {
+                    case "getMatchedTemplates":
+                        return Collections.emptyList();
+                }
+                return null;
+            }
+        });
+        RequestEventImpl event = new RequestEventImpl.Builder()
+                .setExtendedUriInfo(uriInfo)
+                .setException(new NotFoundException(), RequestEvent.ExceptionCause.ORIGINAL)
+                .build(RequestEvent.Type.ON_EXCEPTION);
+        JerseyContext context = new JerseyContext(event);
+        DefaultJerseyObservationConvention convention = new DefaultJerseyObservationConvention("Test-Metric");
+        KeyValues values = convention.getLowCardinalityKeyValues(context);
+        Optional<KeyValue> kv = values.stream().filter(p -> p.getValue().equals("NOT_FOUND")).findFirst();
+        MatcherAssert.assertThat(kv.isPresent(), Matchers.equalTo(true));
+    }
+}