More nullness annotations, and fix some more compiler warnings (kroxylicious#2060)

* More nullness annotations, and fix some more compiler warnings

Signed-off-by: Tom Bentley <[email protected]>

Author: tombentley

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/api/common/FilterRef.java

@@ -12,6 +12,8 @@
 
 import io.kroxylicious.kubernetes.filter.api.v1alpha1.KafkaProtocolFilter;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
+
 /**
  * A reference, used in a kubernetes resource, to a KafkaProxy resource in the same namespace.
  */
@@ -41,12 +43,14 @@ public FilterRefBuilder edit() {
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getGroup() {
         return "filter.kroxylicious.io";
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getKind() {
         return "KafkaProtocolFilter";

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/api/common/IngressRef.java

@@ -12,6 +12,8 @@
 
 import io.kroxylicious.kubernetes.api.v1alpha1.KafkaProxyIngress;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
+
 /**
  * A reference, used in a kubernetes resource, to a KafkaProxyIngress resource in the same namespace.
  */
@@ -41,12 +43,14 @@ public IngressRefBuilder edit() {
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getGroup() {
         return "kroxylicious.io";
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getKind() {
         return "KafkaProxyIngress";

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/api/common/KafkaServiceRef.java

@@ -12,6 +12,8 @@
 
 import io.kroxylicious.kubernetes.api.v1alpha1.KafkaService;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
+
 /**
  * A reference, used in a kubernetes resource, to a KafkaService resource in the same namespace.
  */
@@ -41,12 +43,14 @@ public KafkaServiceRefBuilder edit() {
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getGroup() {
         return "kroxylicious.io";
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getKind() {
         return "KafkaService";

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/api/common/LocalRef.java

@@ -9,21 +9,26 @@
 import java.util.Comparator;
 import java.util.Objects;
 
+import edu.umd.cs.findbugs.annotations.Nullable;
+
 /**
  * Abstraction for references in one kubernetes resource to some kubernetes resource in the same namespace.
  * Two LocalRefs are equal iff they have the same group, kind and name (they don't need to have the same class)
  * @param <T> The Java type of the resource
  */
 public abstract class LocalRef<T> implements Comparable<LocalRef<T>> {
 
-    public static final Comparator<LocalRef<?>> COMPARATOR = Comparator.<LocalRef<?>, String> comparing(LocalRef::getKind)
-            .thenComparing(LocalRef::getGroup)
-            .thenComparing(LocalRef::getName);
+    public static final Comparator<LocalRef<?>> COMPARATOR = Comparator.<LocalRef<?>, String> comparing(LocalRef::getKind, Comparator.nullsLast(String::compareTo))
+            .thenComparing(LocalRef::getGroup, Comparator.nullsLast(String::compareTo))
+            .thenComparing(LocalRef::getName, Comparator.nullsLast(String::compareTo));
 
+    @Nullable
     public abstract String getGroup();
 
+    @Nullable
     public abstract String getKind();
 
+    @Nullable
     public abstract String getName();
 
     @Override

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/api/common/ProxyRef.java

@@ -12,6 +12,8 @@
 
 import io.kroxylicious.kubernetes.api.v1alpha1.KafkaProxy;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
+
 /**
  * A reference, used in a kubernetes resource, to a KafkaProxy resource in the same namespace.
  */
@@ -41,12 +43,14 @@ public ProxyRefBuilder edit() {
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getGroup() {
         return "kroxylicious.io";
     }
 
     @JsonIgnore
+    @NonNull
     @Override
     public String getKind() {
         return "KafkaProxy";

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/operator/ResourcesUtil.java

@@ -7,7 +7,6 @@
 package io.kroxylicious.kubernetes.operator;
 
 import java.util.Collection;
-import java.util.Comparator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -24,14 +23,11 @@
 import io.fabric8.kubernetes.api.model.ObjectMeta;
 import io.fabric8.kubernetes.api.model.OwnerReference;
 import io.fabric8.kubernetes.api.model.OwnerReferenceBuilder;
-import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.api.reconciler.EventSourceContext;
 import io.javaoperatorsdk.operator.processing.event.ResourceID;
 
 import io.kroxylicious.kubernetes.api.common.AnyLocalRefBuilder;
 import io.kroxylicious.kubernetes.api.common.LocalRef;
-import io.kroxylicious.kubernetes.api.v1alpha1.KafkaProxy;
-import io.kroxylicious.kubernetes.api.v1alpha1.VirtualKafkaCluster;
 
 public class ResourcesUtil {
 
@@ -87,12 +83,6 @@ public static <O extends HasMetadata> OwnerReference newOwnerReferenceTo(O owner
                 .build();
     }
 
-    public static Stream<VirtualKafkaCluster> clustersInNameOrder(Context<KafkaProxy> context) {
-        return context.getSecondaryResources(VirtualKafkaCluster.class)
-                .stream()
-                .sorted(Comparator.comparing(ResourcesUtil::name));
-    }
-
     public static String name(HasMetadata resource) {
         return resource.getMetadata().getName();
     }
@@ -158,6 +148,7 @@ public static <T extends HasMetadata> Optional<T> findOnlyResourceNamed(String n
         return Collectors.toMap(ResourcesUtil::toLocalRef, Function.identity());
     }
 
+    @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T extends HasMetadata> LocalRef<T> toLocalRef(T ref) {
         return (LocalRef) new AnyLocalRefBuilder()
                 .withKind(ref.getKind())
@@ -217,8 +208,9 @@ static <O extends HasMetadata, R extends HasMetadata> Set<ResourceID> localRefAs
         return Set.of(new ResourceID(ref.getName(), owner.getMetadata().getNamespace()));
     }
 
-    static <O extends HasMetadata, R extends HasMetadata> Set<ResourceID> localRefsAsResourceIds(O owner, Optional<List<? extends LocalRef<R>>> refs) {
-        return refs.orElse(List.of()).stream()
+    static <O extends HasMetadata, R extends HasMetadata> Set<ResourceID> localRefsAsResourceIds(O owner,
+                                                                                                 List<? extends LocalRef<R>> refs) {
+        return refs.stream()
                 .map(ref -> new ResourceID(ref.getName(), owner.getMetadata().getNamespace()))
                 .collect(Collectors.toSet());
     }

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/operator/VirtualKafkaClusterReconciler.java

@@ -253,7 +253,7 @@ public List<EventSource<?, VirtualKafkaCluster>> prepareEventSources(EventSource
                 VirtualKafkaCluster.class)
                 .withName(INGRESSES_EVENT_SOURCE_NAME)
                 .withPrimaryToSecondaryMapper((VirtualKafkaCluster cluster) -> ResourcesUtil.localRefsAsResourceIds(cluster,
-                        Optional.ofNullable(cluster.getSpec()).map(VirtualKafkaClusterSpec::getIngressRefs)))
+                        Optional.ofNullable(cluster.getSpec()).map(VirtualKafkaClusterSpec::getIngressRefs).orElse(List.of())))
                 .withSecondaryToPrimaryMapper(ingress -> ResourcesUtil.findReferrersMulti(context,
                         ingress,
                         VirtualKafkaCluster.class,
@@ -265,7 +265,7 @@ public List<EventSource<?, VirtualKafkaCluster>> prepareEventSources(EventSource
                 VirtualKafkaCluster.class)
                 .withName(FILTERS_EVENT_SOURCE_NAME)
                 .withPrimaryToSecondaryMapper((VirtualKafkaCluster cluster) -> ResourcesUtil.localRefsAsResourceIds(cluster,
-                        Optional.ofNullable(cluster.getSpec()).map(VirtualKafkaClusterSpec::getFilterRefs)))
+                        Optional.ofNullable(cluster.getSpec()).map(VirtualKafkaClusterSpec::getFilterRefs).orElse(List.of())))
                 .withSecondaryToPrimaryMapper(filter -> ResourcesUtil.findReferrersMulti(context,
                         filter,
                         VirtualKafkaCluster.class,

kroxylicious-operator/src/main/java/io/kroxylicious/kubernetes/operator/resolver/ClusterResolutionResult.java

@@ -29,13 +29,13 @@ public record ClusterResolutionResult(VirtualKafkaCluster cluster,
     public Stream<LocalRef<?>> findDanglingReferences(LocalRef<?> from, String kindTo) {
         Objects.requireNonNull(from);
         Objects.requireNonNull(kindTo);
-        return danglingReferences.stream().filter(r -> r.from().equals(from) && r.to.getKind().equals(kindTo)).map(DanglingReference::to);
+        return danglingReferences.stream().filter(r -> r.from().equals(from) && kindTo.equals(r.to.getKind())).map(DanglingReference::to);
     }
 
     public Stream<LocalRef<?>> findDanglingReferences(String fromKind, String toKind) {
         Objects.requireNonNull(fromKind);
         Objects.requireNonNull(toKind);
-        return danglingReferences.stream().filter(r -> r.from().getKind().equals(fromKind) && r.to().getKind().equals(toKind))
+        return danglingReferences.stream().filter(r -> fromKind.equals(r.from().getKind()) && toKind.equals(r.to().getKind()))
                 .map(DanglingReference::to);
     }
 
@@ -56,7 +56,7 @@ public Stream<LocalRef<?>> findResourcesWithResolvedRefsFalse() {
     }
 
     public Stream<LocalRef<?>> findResourcesWithResolvedRefsFalse(String kind) {
-        return findResourcesWithResolvedRefsFalse().filter(r -> r.getKind().equals(kind));
+        return findResourcesWithResolvedRefsFalse().filter(r -> kind.equals(r.getKind()));
     }
 
     ClusterResolutionResult addAllResourcesHavingResolvedRefsFalse(Set<LocalRef<?>> resolvedRefsFalse) {