INT-3661: Fix the eager BF access from BPPs (P I)

JIRA: https://jira.spring.io/browse/INT-3661

Previously there were a lot of noise from the `PostProcessorRegistrationDelegate$BeanPostProcessorChecker` for early access for beans.
That may produce some side-effects when some of `BeanFactoryPostProcessor`s won't adjust those beans.

The issue is based on two facts:
1. Loading beans from `BPP`, e.g. `IntegrationEvaluationContextAwareBeanPostProcessor` (or `ChannelSecurityInterceptorBeanPostProcessor` - https://jira.spring.io/browse/INT-3663)
2. Loading beans from `setBeanFactory()/setApplicationContext()` container methods

* Move all code from `setBeanFactory()` with access to the `BeanFactory` (e.g. `this.messageBuilderFactory = IntegrationUtils.getMessageBuilderFactory(this.beanFactory);`)
to some other lazy-load methods like `getMessageBuilderFactory()`
* Fix parser tests to remove `messageBuilderFactory` tests since there is no activity for target components to lazy-load them
* Polish some test according the new lazy-load logic
* Rework `IntegrationEvaluationContextAwareBeanPostProcessor` to the `SmartInitializingSingleton` and make it `Ordered`
* Populate `beanFactory` for the internal instance of `connectionFactory` in the `TcpSyslogReceivingChannelAdapter`
* Populate `beanFactory` for the internal `UnicastReceivingChannelAdapter` in the `UdpSyslogReceivingChannelAdapter`
* Add `log.info` that `UdpSyslogReceivingChannelAdapter` overrides `outputChannel` for the provided `UnicastReceivingChannelAdapter`
* Change the internal `MessageChannel` in the `UdpSyslogReceivingChannelAdapter` to the `FixedSubscriberChannel` for better performance

* Fix `AbstractExpressionEvaluator`
* Add JavaDocs for the `IntegrationEvaluationContextAware`

Fix `MongoDbMessageStoreClaimCheckIntegrationTests`

Addressing PR comments

spring-integration-file/src/main/java/org/springframework/integration/file/remote/synchronizer/AbstractInboundFileSynchronizer.java

@@ -151,7 +151,6 @@ public abstract class AbstractInboundFileSynchronizer<F> implements InboundFileS
 	@Override
 	public final void afterPropertiesSet() {
 		Assert.notNull(this.remoteDirectory, "remoteDirectory must not be null");
-		Assert.notNull(this.evaluationContext, "evaluationContext must not be null");
 	}
 
 	protected final List<F> filterFiles(F[] files) {

spring-integration-file/src/main/java/org/springframework/integration/file/transformer/AbstractFilePayloadTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -37,6 +37,7 @@ import org.springframework.util.Assert;
  * Base class for transformers that convert a File payload.
  *
  * @author Mark Fisher
+ * @author Artem Bilan
  */
 public abstract class AbstractFilePayloadTransformer<T> implements Transformer, BeanFactoryAware {
 
@@ -46,6 +47,10 @@ public abstract class AbstractFilePayloadTransformer<T> implements Transformer,
 
 	private volatile MessageBuilderFactory messageBuilderFactory = new DefaultMessageBuilderFactory();
 
+	private boolean messageBuilderFactorySet;
+
+	private volatile BeanFactory beanFactory;
+
 	/**
 	 * Specify whether to delete the File after transformation.
 	 * Default is <em>false</em>.
@@ -58,7 +63,17 @@ public abstract class AbstractFilePayloadTransformer<T> implements Transformer,
 
 	@Override
 	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
-		this.messageBuilderFactory = IntegrationUtils.getMessageBuilderFactory(beanFactory);
+		this.beanFactory = beanFactory;
+	}
+
+	protected MessageBuilderFactory getMessageBuilderFactory() {
+		if (!this.messageBuilderFactorySet) {
+			if (this.beanFactory != null) {
+				this.messageBuilderFactory = IntegrationUtils.getMessageBuilderFactory(this.beanFactory);
+			}
+			this.messageBuilderFactorySet = true;
+		}
+		return this.messageBuilderFactory;
 	}
 
 	@Override
@@ -66,11 +81,11 @@ public abstract class AbstractFilePayloadTransformer<T> implements Transformer,
 		try {
 			Assert.notNull(message, "Message must not be null");
 			Object payload = message.getPayload();
-			Assert.notNull(payload, "Mesasge payload must not be null");
+			Assert.notNull(payload, "Message payload must not be null");
 			Assert.isInstanceOf(File.class, payload, "Message payload must be of type [java.io.File]");
 			File file = (File) payload;
 	        T result = this.transformFile(file);
-	        Message<?> transformedMessage = this.messageBuilderFactory.withPayload(result)
+	        Message<?> transformedMessage = getMessageBuilderFactory().withPayload(result)
 	        		.copyHeaders(message.getHeaders())
 	        		.setHeaderIfAbsent(FileHeaders.ORIGINAL_FILE, file)
 	        		.setHeaderIfAbsent(FileHeaders.FILENAME, file.getName())

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileToStringTransformerParserTests.java

@@ -17,6 +17,7 @@
 package org.springframework.integration.file.config;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertSame;
 
 import org.junit.Test;
@@ -44,9 +45,6 @@ public class FileToStringTransformerParserTests {
     @Qualifier("transformer")
     EventDrivenConsumer endpoint;
 
-    @Autowired
-    MessageBuilderFactory messageBuilderFactory;
-
     @Test
     public void checkDeleteFilesValue() {
         DirectFieldAccessor endpointAccessor = new DirectFieldAccessor(endpoint);
@@ -57,7 +55,6 @@ public class FileToStringTransformerParserTests {
                 handlerAccessor.getPropertyValue("transformer");
         DirectFieldAccessor transformerAccessor = new DirectFieldAccessor(transformer);
         assertEquals(Boolean.TRUE, transformerAccessor.getPropertyValue("deleteFiles"));
-        assertSame(this.messageBuilderFactory, transformerAccessor.getPropertyValue("messageBuilderFactory"));
     }
 
 }