Fix code smell in test and syslog modules (#2667)

* Fix code smell in test and syslog modules

* * Fix code smell in the scripting module

Author: artembilan

spring-integration-scripting/src/main/java/org/springframework/integration/scripting/dsl/DslScriptExecutingMessageProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.integration.scripting.dsl;
 
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.ApplicationContext;
@@ -44,7 +45,7 @@
  * @since 5.0
  */
 class DslScriptExecutingMessageProcessor
-		implements MessageProcessor<Object>, InitializingBean, ApplicationContextAware {
+		implements MessageProcessor<Object>, InitializingBean, ApplicationContextAware, BeanClassLoaderAware {
 
 	private Resource script;
 
@@ -60,6 +61,8 @@ class DslScriptExecutingMessageProcessor
 
 	private AbstractScriptExecutingMessageProcessor<?> delegate;
 
+	private ClassLoader classLoader;
+
 	DslScriptExecutingMessageProcessor(Resource script) {
 		this.script = script;
 	}
@@ -86,7 +89,12 @@ public void setApplicationContext(ApplicationContext applicationContext) throws
 	}
 
 	@Override
-	public void afterPropertiesSet() throws Exception {
+	public void setBeanClassLoader(ClassLoader classLoader) {
+		this.classLoader = classLoader;
+	}
+
+	@Override
+	public void afterPropertiesSet() {
 		if (StringUtils.hasText(this.location)) {
 			this.script = this.applicationContext.getResource(this.location);
 		}
@@ -95,10 +103,13 @@ public void afterPropertiesSet() throws Exception {
 
 		if (!StringUtils.hasText(this.lang)) {
 			String filename = this.script.getFilename();
-			int index = filename.lastIndexOf(".") + 1;
+			int index =
+					filename != null
+							? filename.lastIndexOf(".") + 1
+							: -1;
 			if (index < 1) {
-				throw new BeanCreationException("'lang' isn't provided and there is 'file extension' for script " +
-						"resource: " + this.script);
+				throw new BeanCreationException(
+						"'lang' isn't provided and there is no 'file extension' for script resource: " + this.script);
 			}
 			this.lang = filename.substring(index);
 		}
@@ -115,7 +126,7 @@ public void afterPropertiesSet() throws Exception {
 		}
 
 		this.delegate.setBeanFactory(this.applicationContext);
-		this.delegate.setBeanClassLoader(this.applicationContext.getClassLoader());
+		this.delegate.setBeanClassLoader(this.classLoader);
 	}
 
 	@Override

spring-integration-syslog/src/main/java/org/springframework/integration/syslog/config/SyslogReceivingChannelAdapterFactoryBean.java

@@ -16,6 +16,7 @@
 
 package org.springframework.integration.syslog.config;
 
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanNameAware;
 import org.springframework.beans.factory.config.AbstractFactoryBean;
 import org.springframework.context.ApplicationEventPublisher;
@@ -173,12 +174,13 @@ public void stop(Runnable callback) {
 
 	@Override
 	public Class<?> getObjectType() {
-		return this.adapter == null ? SyslogReceivingChannelAdapterSupport.class :
-				this.adapter.getClass();
+		return this.adapter == null
+				? SyslogReceivingChannelAdapterSupport.class
+				: this.adapter.getClass();
 	}
 
 	@Override
-	protected SyslogReceivingChannelAdapterSupport createInstance() throws Exception {
+	protected SyslogReceivingChannelAdapterSupport createInstance() {
 		SyslogReceivingChannelAdapterSupport adapter;
 		if (this.protocol == Protocol.tcp) {
 			adapter = new TcpSyslogReceivingChannelAdapter();
@@ -187,7 +189,8 @@ protected SyslogReceivingChannelAdapterSupport createInstance() throws Exception
 				((TcpSyslogReceivingChannelAdapter) adapter).setConnectionFactory(this.connectionFactory);
 			}
 			else if (this.applicationEventPublisher != null) {
-				((TcpSyslogReceivingChannelAdapter) adapter).setApplicationEventPublisher(this.applicationEventPublisher);
+				((TcpSyslogReceivingChannelAdapter) adapter)
+						.setApplicationEventPublisher(this.applicationEventPublisher);
 			}
 			Assert.isNull(this.udpAdapter, "Cannot specify 'udp-attributes' when the protocol is 'tcp'");
 		}
@@ -222,12 +225,13 @@ else if (this.protocol == Protocol.udp) {
 		if (this.beanName != null) {
 			adapter.setBeanName(this.beanName);
 		}
-		if (this.getBeanFactory() != null) {
-			adapter.setBeanFactory(this.getBeanFactory());
+		BeanFactory beanFactory = getBeanFactory();
+		if (beanFactory != null) {
+			adapter.setBeanFactory(beanFactory);
 		}
 		adapter.afterPropertiesSet();
 		this.adapter = adapter;
-		return adapter;
+		return this.adapter;
 	}
 
 }

spring-integration-test-support/src/main/java/org/springframework/integration/test/util/TestUtils.java

@@ -174,7 +174,7 @@ public void registerBean(String beanName, Object bean) {
 
 		private String getComponentNameIfNamed(final MessageChannel channel) {
 			Set<Class<?>> interfaces = ClassUtils.getAllInterfacesAsSet(channel);
-			final AtomicReference<String> componentName = new AtomicReference<String>();
+			final AtomicReference<String> componentName = new AtomicReference<>();
 			for (Class<?> intface : interfaces) {
 				if ("org.springframework.integration.support.context.NamedComponent".equals(intface.getName())) {
 					ReflectionUtils.doWithMethods(channel.getClass(), method -> {
@@ -235,12 +235,12 @@ private static class MessagePublishingErrorHandler implements ErrorHandler {
 		}
 
 		@Override
-		public void handleError(Throwable t) {
-			MessageChannel errorChannel = this.resolveErrorChannel(t);
+		public void handleError(Throwable throwable) {
+			MessageChannel errorChannel = resolveErrorChannel(throwable);
 			boolean sent = false;
 			if (errorChannel != null) {
 				try {
-					sent = errorChannel.send(new ErrorMessage(t), 10000);
+					sent = errorChannel.send(new ErrorMessage(throwable), 10000);
 				}
 				catch (Throwable errorDeliveryError) { //NOSONAR
 					// message will be logged only
@@ -253,13 +253,15 @@ public void handleError(Throwable t) {
 				}
 			}
 			if (!sent && logger.isErrorEnabled()) {
-				Message<?> failedMessage = (t instanceof MessagingException) ?
-						((MessagingException) t).getFailedMessage() : null;
+				Message<?> failedMessage =
+						throwable instanceof MessagingException
+								? ((MessagingException) throwable).getFailedMessage()
+								: null;
 				if (failedMessage != null) {
-					logger.error("failure occurred in messaging task with message: " + failedMessage, t);
+					logger.error("failure occurred in messaging task with message: " + failedMessage, throwable);
 				}
 				else {
-					logger.error("failure occurred in messaging task", t);
+					logger.error("failure occurred in messaging task", throwable);
 				}
 			}
 
@@ -268,14 +270,20 @@ public void handleError(Throwable t) {
 		private MessageChannel resolveErrorChannel(Throwable t) {
 			if (t instanceof MessagingException) {
 				Message<?> failedMessage = ((MessagingException) t).getFailedMessage();
+				if (failedMessage == null) {
+					return null;
+				}
 				Object errorChannelHeader = failedMessage.getHeaders().getErrorChannel();
 				if (errorChannelHeader instanceof MessageChannel) {
 					return (MessageChannel) errorChannelHeader;
 				}
-				Assert.isInstanceOf(String.class, errorChannelHeader, "Unsupported error channel header type. " +
-						"Expected MessageChannel or String, but actual type is [" +
-						errorChannelHeader.getClass() + "]");
-				return this.context.getBean((String) errorChannelHeader, MessageChannel.class);
+				else if (errorChannelHeader instanceof String) {
+					return this.context.getBean((String) errorChannelHeader, MessageChannel.class);
+				}
+				else {
+					throw new IllegalStateException("Unsupported error channel header type. " +
+							"Expected MessageChannel or String, but actual header is [" + errorChannelHeader + "]");
+				}
 			}
 			else {
 				return null;

spring-integration-test/src/main/java/org/springframework/integration/test/context/MockIntegrationContext.java

@@ -148,8 +148,10 @@ public void substituteMessageHandlerFor(String consumerEndpointId, MessageHandle
 		}
 		DirectFieldAccessor directFieldAccessor = new DirectFieldAccessor(endpoint);
 		Object targetMessageHandler = directFieldAccessor.getPropertyValue("handler");
+		Assert.notNull(targetMessageHandler, () -> "'handler' must not be null in the: " + endpoint);
 		if (endpoint instanceof ReactiveStreamsConsumer) {
 			Object targetSubscriber = directFieldAccessor.getPropertyValue("subscriber");
+			Assert.notNull(targetSubscriber, () -> "'subscriber' must not be null in the: " + endpoint);
 			this.beans.put(consumerEndpointId, Tuples.of(targetMessageHandler, targetSubscriber));
 		}
 		else {