Issue ReactiveX#288: Improve Kotlin support via Nullability annotations

build.gradle

@@ -15,6 +15,7 @@ buildscript {
         classpath "org.ajoberstar:gradle-git:1.3.2"
         classpath "org.jfrog.buildinfo:build-info-extractor-gradle:4.4.17"
         classpath 'com.github.erizo.gradle:jcstress-gradle-plugin:0.8.0'
+        classpath "com.netflix.nebula:gradle-extra-configurations-plugin:4.0.1"
     }
 }
 
@@ -55,9 +56,14 @@ configure(project.coreProjects) {
     apply plugin: 'maven-publish'
     apply plugin: 'com.jfrog.bintray'
     apply from: "${rootDir}/publishing.gradle"
+    apply plugin: 'nebula.optional-base'
+
     dependencies {
         compile ( libraries.vavr)
         compile ( libraries.slf4j)
+
+        // JSR-305 only used for non-required meta-annotations
+        compile "com.google.code.findbugs:jsr305:3.0.2", optional
 
         testCompile ( libraries.junit)
         testCompile ( libraries.assertj)

resilience4j-all/src/main/java/io/github/resilience4j/decorators/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.decorators;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-bulkhead/src/main/java/io/github/resilience4j/bulkhead/event/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.bulkhead.event;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-bulkhead/src/main/java/io/github/resilience4j/bulkhead/internal/SemaphoreBulkhead.java

@@ -27,6 +27,7 @@
 import io.github.resilience4j.bulkhead.event.BulkheadOnCallRejectedEvent;
 import io.github.resilience4j.core.EventConsumer;
 import io.github.resilience4j.core.EventProcessor;
+import io.github.resilience4j.core.lang.Nullable;
 
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
@@ -50,7 +51,7 @@ public class SemaphoreBulkhead implements Bulkhead {
      * @param name           the name of this bulkhead
      * @param bulkheadConfig custom bulkhead configuration
      */
-    public SemaphoreBulkhead(String name, BulkheadConfig bulkheadConfig) {
+    public SemaphoreBulkhead(String name, @Nullable BulkheadConfig bulkheadConfig) {
         this.name = name;
         this.config = bulkheadConfig != null ? bulkheadConfig
                 : BulkheadConfig.ofDefaults();

resilience4j-bulkhead/src/main/java/io/github/resilience4j/bulkhead/internal/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.bulkhead.internal;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-bulkhead/src/main/java/io/github/resilience4j/bulkhead/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.bulkhead;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-bulkhead/src/main/java/io/github/resilience4j/bulkhead/utils/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.bulkhead.utils;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-cache/src/main/java/io/github/resilience4j/cache/event/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.cache.event;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-cache/src/main/java/io/github/resilience4j/cache/internal/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.cache.internal;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-cache/src/main/java/io/github/resilience4j/cache/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.cache;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/CircuitBreakerConfig.java

@@ -18,6 +18,8 @@
  */
 package io.github.resilience4j.circuitbreaker;
 
+import io.github.resilience4j.core.lang.Nullable;
+
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.Optional;
@@ -89,8 +91,8 @@ public static CircuitBreakerConfig ofDefaults(){
     }
 
     public static class Builder {
-        private Predicate<Throwable> recordFailurePredicate;
-        private Predicate<Throwable> errorRecordingPredicate;
+        @Nullable private Predicate<Throwable> recordFailurePredicate;
+        @Nullable private Predicate<Throwable> errorRecordingPredicate;
         @SuppressWarnings("unchecked")
         private Class<? extends Throwable>[] recordExceptions = new Class[0];
         @SuppressWarnings("unchecked")
@@ -248,7 +250,9 @@ public CircuitBreakerConfig build() {
             config.failureRateThreshold = failureRateThreshold;
             config.ringBufferSizeInClosedState = ringBufferSizeInClosedState;
             config.ringBufferSizeInHalfOpenState = ringBufferSizeInHalfOpenState;
-            config.recordFailurePredicate = errorRecordingPredicate;
+            if(errorRecordingPredicate != null) {
+                config.recordFailurePredicate = errorRecordingPredicate;
+            }
             config.automaticTransitionFromOpenToHalfOpenEnabled = automaticTransitionFromOpenToHalfOpenEnabled;
             return config;
         }

resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/event/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.circuitbreaker.event;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/internal/CircuitBreakerMetrics.java

@@ -20,6 +20,7 @@
 
 
 import io.github.resilience4j.circuitbreaker.CircuitBreaker;
+import io.github.resilience4j.core.lang.Nullable;
 
 import java.util.concurrent.atomic.LongAdder;
 
@@ -33,7 +34,7 @@ class CircuitBreakerMetrics implements CircuitBreaker.Metrics {
         this(ringBufferSize, null);
     }
 
-    CircuitBreakerMetrics(int ringBufferSize, RingBitSet sourceSet) {
+    CircuitBreakerMetrics(int ringBufferSize, @Nullable RingBitSet sourceSet) {
         this.ringBufferSize = ringBufferSize;
         if(sourceSet != null) {
             this.ringBitSet = new RingBitSet(this.ringBufferSize, sourceSet);

resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/internal/ClosedState.java

@@ -20,6 +20,7 @@
 
 import io.github.resilience4j.circuitbreaker.CircuitBreaker;
 import io.github.resilience4j.circuitbreaker.CircuitBreakerConfig;
+import io.github.resilience4j.core.lang.Nullable;
 
 final class ClosedState extends CircuitBreakerState {
 
@@ -30,7 +31,7 @@ final class ClosedState extends CircuitBreakerState {
         this(stateMachine, null);
     }
 
-    ClosedState(CircuitBreakerStateMachine stateMachine, CircuitBreakerMetrics circuitBreakerMetrics) {
+    ClosedState(CircuitBreakerStateMachine stateMachine, @Nullable CircuitBreakerMetrics circuitBreakerMetrics) {
         super(stateMachine);
         CircuitBreakerConfig circuitBreakerConfig = stateMachine.getCircuitBreakerConfig();
         if(circuitBreakerMetrics == null){

resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/internal/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.circuitbreaker.internal;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;

resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/package-info.java

@@ -0,0 +1,24 @@
+/*
+ *
+ *  Copyright 2018: Clint Checketts
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *
+ */
+@NonNullApi
+@NonNullFields
+package io.github.resilience4j.circuitbreaker;
+
+import io.github.resilience4j.core.lang.NonNullApi;
+import io.github.resilience4j.core.lang.NonNullFields;