Fix Async instrumentation when using AsyncConfigurerSupport (#251)

* fix issue-183(@async instrumentation not working when using AsyncConfigurerSupport)

Author: wuyupengwoaini

instrument-starters/opentracing-spring-cloud-core/src/main/java/io/opentracing/contrib/spring/cloud/async/CustomAsyncConfigurerAutoConfiguration.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2017-2018 The OpenTracing Authors
+ * Copyright 2017-2019 The OpenTracing Authors
  *
  * 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
@@ -25,6 +25,7 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.PriorityOrdered;
 import org.springframework.scheduling.annotation.AsyncConfigurer;
 
 /**
@@ -39,7 +40,7 @@
 @AutoConfigureBefore(DefaultAsyncAutoConfiguration.class)
 @AutoConfigureAfter(TracerAutoConfiguration.class)
 @ConditionalOnProperty(name = "opentracing.spring.cloud.async.enabled", havingValue = "true", matchIfMissing = true)
-public class CustomAsyncConfigurerAutoConfiguration implements BeanPostProcessor {
+public class CustomAsyncConfigurerAutoConfiguration implements BeanPostProcessor,PriorityOrdered {
 
   @Autowired
   private Tracer tracer;
@@ -52,10 +53,15 @@ public Object postProcessBeforeInitialization(Object bean, String beanName)
 
   @Override
   public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
-    if (bean instanceof AsyncConfigurer) {
+    if (bean instanceof AsyncConfigurer && !(bean instanceof TracedAsyncConfigurer)) {
       AsyncConfigurer configurer = (AsyncConfigurer) bean;
       return new TracedAsyncConfigurer(tracer, configurer);
     }
     return bean;
   }
+
+  @Override
+  public int getOrder() {
+    return PriorityOrdered.LOWEST_PRECEDENCE;
+  }
 }

instrument-starters/opentracing-spring-cloud-core/src/test/java/io/opentracing/contrib/spring/cloud/async/AsyncConfigurerTest.java

@@ -0,0 +1,63 @@
+/**
+ * Copyright 2017-2019 The OpenTracing Authors
+ *
+ * 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.
+ */
+package io.opentracing.contrib.spring.cloud.async;
+
+import io.opentracing.contrib.spring.cloud.MockTracingConfiguration;
+import io.opentracing.contrib.spring.cloud.async.instrument.TracedAsyncConfigurer;
+import java.util.concurrent.Executor;
+import org.assertj.core.api.BDDAssertions;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.AsyncConfigurer;
+import org.springframework.scheduling.annotation.AsyncConfigurerSupport;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+
+
+
+/**
+ * @Author wuyupeng
+ **/
+@SpringBootTest(classes = {AsyncConfigurerTest.AsyncConfigurerConfig.class, MockTracingConfiguration.class, CustomAsyncConfigurerAutoConfiguration.class})
+@RunWith(SpringJUnit4ClassRunner.class)
+public class AsyncConfigurerTest {
+
+  @Autowired
+  private AsyncConfigurer asyncConfigurer;
+
+
+  @Configuration
+  @EnableAsync
+  static class AsyncConfigurerConfig extends AsyncConfigurerSupport {
+    @Override
+    public Executor getAsyncExecutor() {
+      ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
+      executor.initialize();
+      return executor;
+    }
+  }
+
+  /**
+   * Test if the AsyncConfigurer configured by developer can be replaced with TracedAsyncConfigurer by CustomAsyncConfigurerAutoConfiguration
+   */
+  @Test
+  public void testIsTracedAsyncConfigurer() {
+    BDDAssertions.then(asyncConfigurer).isInstanceOf(TracedAsyncConfigurer.class);
+  }
+}