GH-106: Allow null for S3MH.objectAclExpression

Fixes #106

It is really OK to have a `null` returned for the
`S3MessageHandler.objectAclExpression` with the meaning do not set any
ACL on the S3 object.

* Allow `null` for `objectAclExpression` evaluation result
* Optimize asserts skipping string concatenation until the `Supplier`
invocation
* Introduce a `S3MessageHandler.MessageS3ProgressListener` to have a
request message context in the `progressChanged` event case

Author: artembilan

src/main/java/org/springframework/integration/aws/outbound/S3MessageHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2019 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.
@@ -69,11 +69,13 @@
  * invocation. Consider to use an async upstream hand off if this blocking behavior isn't appropriate.
  * <p>
  * The "request-reply" behavior is async and the {@link Transfer} result from the {@link TransferManager}
- * operation is sent to the {@link #outputChannel}, assuming the transfer progress observation in the
+ * operation is sent to the {@link #getOutputChannel()}, assuming the transfer progress observation in the
  * downstream flow.
  * <p>
  * The {@link S3ProgressListener} can be supplied to track the transfer progress.
  * Also the listener can be populated into the returned {@link Transfer} afterwards in the downstream flow.
+ * If the context of the {@code requestMessage} is important in the {@code progressChanged} event, it is
+ * recommended to use a {@link MessageS3ProgressListener} implementation instead.
  * * <p>
  * For the upload operation the {@link UploadMetadataProvider} callback can be supplied to populate required
  * {@link ObjectMetadata} options, as for a single entry, as well as for each file in directory to upload.
@@ -131,12 +133,8 @@ public S3MessageHandler(AmazonS3 amazonS3, Expression bucketExpression) {
 	}
 
 	public S3MessageHandler(AmazonS3 amazonS3, String bucket, boolean produceReply) {
-		this(TransferManagerBuilder.standard()
-						.withS3Client(amazonS3)
-						.build(),
-				bucket,
-				produceReply);
-		Assert.notNull(amazonS3, "'amazonS3' must not be null");
+		this(amazonS3, new LiteralExpression(bucket), produceReply);
+		Assert.notNull(bucket, "'bucket' must not be null");
 	}
 
 	public S3MessageHandler(AmazonS3 amazonS3, Expression bucketExpression, boolean produceReply) {
@@ -228,6 +226,7 @@ public void setDestinationKeyExpression(Expression destinationKeyExpression) {
 	/**
 	 * Specify a {@link S3ProgressListener} for upload and download operations.
 	 * @param s3ProgressListener the {@link S3ProgressListener} to use.
+	 * @see MessageS3ProgressListener
 	 */
 	public void setProgressListener(S3ProgressListener s3ProgressListener) {
 		this.s3ProgressListener = s3ProgressListener;
@@ -260,9 +259,8 @@ protected void doInit() {
 	@Override
 	protected Object handleRequestMessage(Message<?> requestMessage) {
 		Command command = this.commandExpression.getValue(this.evaluationContext, requestMessage, Command.class);
-		Assert.state(command != null, "'commandExpression' ["
-				+ this.commandExpression.getExpressionString()
-				+ "] cannot evaluate to null.");
+		Assert.state(command != null, () ->
+				"'commandExpression' [" + this.commandExpression.getExpressionString() + "] cannot evaluate to null.");
 
 		Transfer transfer = null;
 
@@ -327,8 +325,8 @@ private Transfer upload(Message<?> requestMessage) {
 					InputStream inputStream = (InputStream) payload;
 					if (metadata.getContentMD5() == null) {
 						Assert.state(inputStream.markSupported(),
-								"For an upload InputStream with no MD5 digest metadata, the " +
-										"markSupported() method must evaluate to true. ");
+								"For an upload InputStream with no MD5 digest metadata, " +
+										"the markSupported() method must evaluate to true.");
 						String contentMd5 = Md5Utils.md5AsBase64(inputStream);
 						metadata.setContentMD5(contentMd5);
 						inputStream.reset();
@@ -350,7 +348,9 @@ else if (payload instanceof File) {
 					if (metadata.getContentType() == null) {
 						metadata.setContentType(Mimetypes.getInstance().getMimetype(fileToUpload));
 					}
-					putObjectRequest = new PutObjectRequest(bucketName, key, fileToUpload).withMetadata(metadata);
+					putObjectRequest =
+							new PutObjectRequest(bucketName, key, fileToUpload)
+									.withMetadata(metadata);
 				}
 				else if (payload instanceof byte[]) {
 					byte[] payloadBytes = (byte[]) payload;
@@ -387,12 +387,30 @@ else if (payload instanceof byte[]) {
 				}
 			}
 
-			S3ProgressListener progressListener = this.s3ProgressListener;
+			S3ProgressListener configuredProgressListener = this.s3ProgressListener;
+			if (this.s3ProgressListener instanceof MessageS3ProgressListener) {
+				configuredProgressListener = new S3ProgressListener() {
+
+					@Override
+					public void onPersistableTransfer(PersistableTransfer persistableTransfer) {
+						S3MessageHandler.this.s3ProgressListener.onPersistableTransfer(persistableTransfer);
+					}
+
+					@Override
+					public void progressChanged(ProgressEvent progressEvent) {
+						((MessageS3ProgressListener) S3MessageHandler.this.s3ProgressListener)
+								.progressChanged(progressEvent, requestMessage);
+					}
+
+				};
+			}
+
+			S3ProgressListener progressListener = configuredProgressListener;
 
 			if (this.objectAclExpression != null) {
 				Object acl = this.objectAclExpression.getValue(this.evaluationContext, requestMessage);
-				Assert.state(acl instanceof AccessControlList || acl instanceof CannedAccessControlList,
-						"The 'objectAclExpression' ["
+				Assert.state(acl == null || acl instanceof AccessControlList || acl instanceof CannedAccessControlList,
+						() -> "The 'objectAclExpression' ["
 								+ this.objectAclExpression.getExpressionString()
 								+ "] must evaluate to com.amazonaws.services.s3.model.AccessControlList " +
 								"or must evaluate to com.amazonaws.services.s3.model.CannedAccessControlList. " +
@@ -424,8 +442,8 @@ public void progressChanged(ProgressEvent progressEvent) {
 
 				};
 
-				if (this.s3ProgressListener != null) {
-					progressListener = new S3ProgressListenerChain(this.s3ProgressListener, progressListener);
+				if (configuredProgressListener != null) {
+					progressListener = new S3ProgressListenerChain(configuredProgressListener, progressListener);
 				}
 
 			}
@@ -441,8 +459,9 @@ public void progressChanged(ProgressEvent progressEvent) {
 
 	private Transfer download(Message<?> requestMessage) {
 		Object payload = requestMessage.getPayload();
-		Assert.state(payload instanceof File, "For the 'DOWNLOAD' operation the 'payload' must be of " +
-				"'java.io.File' type, but gotten: [" + payload.getClass() + ']');
+		Assert.state(payload instanceof File,
+				() -> "For the 'DOWNLOAD' operation the 'payload' must be of " +
+						"'java.io.File' type, but gotten: [" + payload.getClass() + ']');
 
 		File targetFile = (File) payload;
 
@@ -457,7 +476,7 @@ private Transfer download(Message<?> requestMessage) {
 		}
 
 		Assert.state(key != null,
-				"The 'keyExpression' must not be null for non-File payloads and can't evaluate to null. " +
+				() -> "The 'keyExpression' must not be null for non-File payloads and can't evaluate to null. " +
 						"Root object is: " + requestMessage);
 
 		if (targetFile.isDirectory()) {
@@ -483,7 +502,7 @@ private Transfer copy(Message<?> requestMessage) {
 		}
 
 		Assert.state(sourceKey != null,
-				"The 'keyExpression' must not be null for 'copy' operation " +
+				() -> "The 'keyExpression' must not be null for 'copy' operation " +
 						"and 'keyExpression' can't evaluate to null. " +
 						"Root object is: " + requestMessage);
 
@@ -498,8 +517,8 @@ private Transfer copy(Message<?> requestMessage) {
 		}
 
 		Assert.state(destinationBucketName != null,
-				"The 'destinationBucketExpression' must not be null for 'copy' operation and can't evaluate to null. " +
-						"Root object is: " + requestMessage);
+				() -> "The 'destinationBucketExpression' must not be null for 'copy' operation " +
+						"and can't evaluate to null. Root object is: " + requestMessage);
 
 		String destinationKey = null;
 		if (this.destinationKeyExpression != null) {
@@ -508,8 +527,8 @@ private Transfer copy(Message<?> requestMessage) {
 		}
 
 		Assert.state(destinationKey != null,
-				"The 'destinationKeyExpression' must not be null for 'copy' operation and can't evaluate to null. " +
-						"Root object is: " + requestMessage);
+				() -> "The 'destinationKeyExpression' must not be null for 'copy' operation " +
+						"and can't evaluate to null. Root object is: " + requestMessage);
 
 
 		CopyObjectRequest copyObjectRequest =
@@ -525,9 +544,10 @@ private String obtainBucket(Message<?> requestMessage) {
 		else {
 			bucketName = this.bucketExpression.getValue(this.evaluationContext, requestMessage, String.class);
 		}
-		Assert.state(bucketName != null, "The 'bucketExpression' ["
-				+ this.bucketExpression.getExpressionString()
-				+ "] must not evaluate to null. Root object is: " + requestMessage);
+		Assert.state(bucketName != null,
+				() -> "The 'bucketExpression' ["
+						+ this.bucketExpression.getExpressionString()
+						+ "] must not evaluate to null. Root object is: " + requestMessage);
 
 		if (this.resourceIdResolver != null) {
 			bucketName = this.resourceIdResolver.resolveToPhysicalResourceId(bucketName);
@@ -560,6 +580,23 @@ public enum Command {
 
 	}
 
+	/**
+	 * An {@link S3ProgressListener} extension to provide a {@code requestMessage}
+	 * context for the {@code progressChanged} event.
+	 *
+	 * @since 2.1
+	 */
+	public interface MessageS3ProgressListener extends S3ProgressListener {
+
+		@Override
+		default void progressChanged(ProgressEvent progressEvent) {
+			throw new UnsupportedOperationException("Use progressChanged(ProgressEvent, Message<?>) instead.");
+		}
+
+		void progressChanged(ProgressEvent progressEvent, Message<?> message);
+
+	}
+
 	/**
 	 * The callback to populate an {@link ObjectMetadata} for upload operation.
 	 * The message can be used as a metadata source.

src/main/resources/org/springframework/integration/aws/config/spring-integration-aws-2.0.xsd

@@ -179,6 +179,9 @@
 			<xsd:annotation>
 				<xsd:documentation>
 					Reference to an instance of 'com.amazonaws.services.s3.transfer.internal.S3ProgressListener'.
+					For the request message context propagation into the 'progressChanged' event it is recommended
+					to use a 'org.springframework.integration.aws.outbound.S3MessageHandler.MessageS3ProgressListener'
+					instead.
 				</xsd:documentation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
@@ -460,7 +463,7 @@
 				</xsd:documentation>
 			</xsd:annotation>
 			<xsd:simpleType>
-				<xsd:union memberTypes="xsd:boolean xsd:string" />
+				<xsd:union memberTypes="xsd:boolean xsd:string"/>
 			</xsd:simpleType>
 		</xsd:attribute>
 		<xsd:attribute name="send-timeout">
@@ -485,7 +488,7 @@
 			<xsd:annotation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
-						<tool:expected-type type="org.springframework.integration.support.ErrorMessageStrategy" />
+						<tool:expected-type type="org.springframework.integration.support.ErrorMessageStrategy"/>
 					</tool:annotation>
 				</xsd:appinfo>
 				<xsd:documentation>
@@ -498,7 +501,7 @@
 			<xsd:annotation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
-						<tool:expected-type type="org.springframework.messaging.MessageChannel" />
+						<tool:expected-type type="org.springframework.messaging.MessageChannel"/>
 					</tool:annotation>
 				</xsd:appinfo>
 				<xsd:documentation>
@@ -510,7 +513,7 @@
 			<xsd:annotation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
-						<tool:expected-type type="org.springframework.messaging.MessageChannel" />
+						<tool:expected-type type="org.springframework.messaging.MessageChannel"/>
 					</tool:annotation>
 				</xsd:appinfo>
 				<xsd:documentation>
@@ -522,7 +525,7 @@
 			<xsd:annotation>
 				<xsd:appinfo>
 					<tool:annotation kind="ref">
-						<tool:expected-type type="com.amazonaws.handlers.AsyncHandler" />
+						<tool:expected-type type="com.amazonaws.handlers.AsyncHandler"/>
 					</tool:annotation>
 				</xsd:appinfo>
 				<xsd:documentation>