Fix @OnTransition with other annotations

spring-statemachine-core/src/main/java/org/springframework/statemachine/processor/StateMachineAnnotationPostProcessor.java

@@ -122,7 +122,7 @@ public class StateMachineAnnotationPostProcessor implements BeanPostProcessor, B
 					Annotation metaAnnotation = null;
 					for (Class<? extends Annotation> ppa : postProcessors.keySet()) {
 						Annotation a = AnnotationUtils.getAnnotation(annotation,ppa);
-						if (annotation.getClass().equals(a.getClass())) {
+						if (a != null && annotation.getClass().equals(a.getClass())) {
 							metaAnnotation = a;
 						} else {
 							metaAnnotation = a;

spring-statemachine-core/src/test/java/org/springframework/statemachine/processor/StateMachineAnnotationPostProcessorTests.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2015 the original author or 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 org.springframework.statemachine.processor;
+
+import java.util.EnumSet;
+import java.util.concurrent.CountDownLatch;
+
+import org.junit.Test;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.statemachine.AbstractStateMachineTests;
+import org.springframework.statemachine.StateMachineSystemConstants;
+import org.springframework.statemachine.annotation.OnTransition;
+import org.springframework.statemachine.annotation.WithStateMachine;
+import org.springframework.statemachine.config.EnableStateMachine;
+import org.springframework.statemachine.config.EnumStateMachineConfigurerAdapter;
+import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
+import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
+
+public class StateMachineAnnotationPostProcessorTests extends AbstractStateMachineTests {
+
+	@Override
+	protected AnnotationConfigApplicationContext buildContext() {
+		return new AnnotationConfigApplicationContext();
+	}
+
+	@Test
+	public void testWithOtherAnnotations() {
+		context.register(Config1.class, BeanConfig1.class);
+		context.refresh();
+	}
+
+	@WithStateMachine
+	static class Bean1 {
+
+		CountDownLatch onMethod1Latch = new CountDownLatch(1);
+		CountDownLatch onOnTransitionFromS2ToS3Latch = new CountDownLatch(1);
+
+		@OnTransition(source = "S1", target = "S2")
+		public void method1() {
+			onMethod1Latch.countDown();
+		}
+
+		@OnTransition
+		public void onTransitionFromS2ToS3() {
+			onOnTransitionFromS2ToS3Latch.countDown();
+		}
+
+		@Bean
+		public String dummy() {
+			return "dummy";
+		}
+
+	}
+
+	@Configuration
+	static class BeanConfig1 {
+
+		@Bean
+		public Bean1 bean1() {
+			return new Bean1();
+		}
+
+	}
+
+	@Configuration
+	@EnableStateMachine(name = {StateMachineSystemConstants.DEFAULT_ID_STATEMACHINE, "fooMachine"})
+	static class Config1 extends EnumStateMachineConfigurerAdapter<TestStates, TestEvents> {
+
+		@Override
+		public void configure(StateMachineStateConfigurer<TestStates, TestEvents> states) throws Exception {
+			states
+				.withStates()
+					.initial(TestStates.S1)
+					.states(EnumSet.allOf(TestStates.class));
+		}
+
+		@Override
+		public void configure(StateMachineTransitionConfigurer<TestStates, TestEvents> transitions) throws Exception {
+			transitions
+				.withExternal()
+					.source(TestStates.S1)
+					.target(TestStates.S2)
+					.event(TestEvents.E1);
+		}
+
+	}
+
+}