Sonar fixes

Critical issues `o.s.i.t*`, `o.s.i.u*`.

* Polishing - PR Comments.

spring-integration-core/src/main/java/org/springframework/integration/store/AbstractKeyValueMessageStore.java

@@ -146,6 +146,7 @@ public abstract class AbstractKeyValueMessageStore extends AbstractMessageGroupS
 	protected void doAddMessage(Message<?> message) {
 		Assert.notNull(message, "'message' must not be null");
 		UUID messageId = message.getHeaders().getId();
+		Assert.notNull(messageId, "Cannot store messages without an ID header");
 		doStoreIfAbsent(this.messagePrefix + messageId, new MessageHolder(message));
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/store/SimpleMessageStore.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -182,7 +182,9 @@ public class SimpleMessageStore extends AbstractMessageGroupStore
 					+ this.individualCapacity
 					+ "), try constructing it with a larger capacity.");
 		}
-		this.idToMessage.put(message.getHeaders().getId(), message);
+		UUID id = message.getHeaders().getId();
+		Assert.notNull(id, "ID header must not be null");
+		this.idToMessage.put(id, message);
 		return message;
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/transformer/ClaimCheckInTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.integration.transformer;
 
+import java.util.UUID;
+
 import org.springframework.integration.store.MessageStore;
 import org.springframework.integration.support.AbstractIntegrationMessageBuilder;
 import org.springframework.messaging.Message;
@@ -51,10 +53,10 @@ public class ClaimCheckInTransformer extends AbstractTransformer {
 	@Override
 	protected Object doTransform(Message<?> message) throws Exception {
 		Assert.notNull(message, "message must not be null");
-		Object payload = message.getPayload();
-		Assert.notNull(payload, "payload must not be null");
-		Message<?> storedMessage = this.messageStore.addMessage(message);
-		AbstractIntegrationMessageBuilder<?> responseBuilder = this.getMessageBuilderFactory().withPayload(storedMessage.getHeaders().getId());
+		UUID id = message.getHeaders().getId();
+		Assert.notNull(id, "ID header must not be null");
+		this.messageStore.addMessage(message);
+		AbstractIntegrationMessageBuilder<?> responseBuilder = getMessageBuilderFactory().withPayload(id);
 		// headers on the 'current' message take precedence
 		responseBuilder.copyHeaders(message.getHeaders());
 		return responseBuilder.build();

spring-integration-core/src/main/java/org/springframework/integration/transformer/ContentEnricher.java

@@ -375,7 +375,9 @@ public class ContentEnricher extends AbstractReplyProducingMessageHandler implem
 		else {
 			final Object requestMessagePayload =
 					this.requestPayloadExpression.getValue(this.sourceEvaluationContext, requestMessage);
-			actualRequestMessage = this.getMessageBuilderFactory().withPayload(requestMessagePayload)
+			Assert.state(requestMessagePayload != null,
+					() -> "Request payload expression produced null for " + requestMessage);
+			actualRequestMessage = getMessageBuilderFactory().withPayload(requestMessagePayload)
 					.copyHeaders(requestMessage.getHeaders()).build();
 		}
 		final Message<?> replyMessage;

spring-integration-core/src/main/java/org/springframework/integration/util/DynamicPeriodicTrigger.java

@@ -217,13 +217,14 @@ public class DynamicPeriodicTrigger implements Trigger {
 	 */
 	@Override
 	public Date nextExecutionTime(TriggerContext triggerContext) {
-		if (triggerContext.lastScheduledExecutionTime() == null) {
+		Date lastScheduled = triggerContext.lastScheduledExecutionTime();
+		if (lastScheduled == null) {
 			return new Date(System.currentTimeMillis() + this.initialDuration.toMillis());
 		}
 		else if (this.fixedRate) {
-			return new Date(triggerContext.lastScheduledExecutionTime().getTime() + this.duration.toMillis());
+			return new Date(lastScheduled.getTime() + this.duration.toMillis());
 		}
-		return new Date(triggerContext.lastCompletionTime().getTime() + this.duration.toMillis());
+		return new Date(triggerContext.lastCompletionTime().getTime() + this.duration.toMillis()); // NOSONAR never null here
 	}
 
 	@Override

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/store/JdbcMessageStore.java

@@ -327,6 +327,7 @@ public class JdbcMessageStore extends AbstractMessageGroupStore implements Messa
 	@SuppressWarnings("unchecked")
 	public <T> Message<T> addMessage(final Message<T> message) {
 		UUID id = message.getHeaders().getId();
+		Assert.notNull(id, "Cannot store messages without an ID header");
 		final String messageId = getKey(id);
 		final byte[] messageBytes = this.serializer.convert(message);
 

spring-integration-mongodb/src/main/java/org/springframework/integration/mongodb/store/MessageDocument.java

@@ -77,6 +77,7 @@ public class MessageDocument {
 	@PersistenceConstructor
 	MessageDocument(Message<?> message, UUID messageId) {
 		Assert.notNull(message, "'message' must not be null");
+		Assert.notNull(messageId, "'message' ID header must not be null");
 		this.message = message;
 		this.messageId = messageId;
 	}

spring-integration-mongodb/src/main/java/org/springframework/integration/mongodb/store/MongoDbMessageStore.java

@@ -212,6 +212,7 @@ public class MongoDbMessageStore extends AbstractMessageGroupStore
 
 	private void addMessageDocument(MessageWrapper document) {
 		UUID messageId = (UUID) document.headers.get(MessageHeaders.ID);
+		Assert.notNull(messageId, "ID header must not be null");
 		Query query = whereMessageIdIsAndGroupIdIs(messageId, document.get_GroupId());
 		if (!this.template.exists(query, MessageWrapper.class, this.collectionName)) {
 			if (document.get_Group_timestamp() == 0) {