GH-9452: Expose ZipTransformer.setFileNameGenerator()

Fixes: #9452
Issue link: #9452

* Move the logic about `fileNameGenerator` configuration out of `AbstractZipTransformer`
since this property is not used by `UnZipTransformer` implementation
* Add more docs about `ZipTransformer` logic

Author: artembilan

spring-integration-zip/src/main/java/org/springframework/integration/zip/transformer/AbstractZipTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 the original author or authors.
+ * Copyright 2015-2024 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.
@@ -19,8 +19,6 @@
 import java.io.File;
 import java.nio.charset.Charset;
 
-import org.springframework.integration.file.DefaultFileNameGenerator;
-import org.springframework.integration.file.FileNameGenerator;
 import org.springframework.integration.transformer.AbstractTransformer;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
@@ -37,8 +35,6 @@ public abstract class AbstractZipTransformer extends AbstractTransformer {
 
 	protected Charset charset = Charset.defaultCharset();
 
-	protected FileNameGenerator fileNameGenerator;
-
 	protected ZipResultType zipResultType = ZipResultType.FILE;
 
 	protected File workDirectory =
@@ -91,11 +87,6 @@ protected void onInit() {
 			logger.info(() -> "Creating work directory: " + this.workDirectory);
 			Assert.isTrue(this.workDirectory.mkdirs(), () -> "Can't create the 'workDirectory': " + this.workDirectory);
 		}
-		DefaultFileNameGenerator defaultFileNameGenerator = new DefaultFileNameGenerator();
-		defaultFileNameGenerator.setBeanFactory(getBeanFactory());
-		defaultFileNameGenerator.setConversionService(getConversionService());
-		this.fileNameGenerator = defaultFileNameGenerator;
-
 	}
 
 	/**

spring-integration-zip/src/main/java/org/springframework/integration/zip/transformer/ZipTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 the original author or authors.
+ * Copyright 2015-2024 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.
@@ -29,10 +29,13 @@
 import org.zeroturnaround.zip.FileSource;
 import org.zeroturnaround.zip.ZipEntrySource;
 
+import org.springframework.integration.file.DefaultFileNameGenerator;
 import org.springframework.integration.file.FileHeaders;
+import org.springframework.integration.file.FileNameGenerator;
 import org.springframework.integration.transformer.Transformer;
 import org.springframework.integration.zip.ZipHeaders;
 import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.Assert;
 import org.springframework.util.FileCopyUtils;
 import org.springframework.util.StringUtils;
@@ -43,9 +46,6 @@
  * <p>
  * See also: <a href="https://www.mindprod.com/jgloss/zip.html"/>
  * <p>
- * If you want to generate Zip files larger than {@code 4GB}, you must use Java 7:
- * <p>
- * See also: <a href="https://blogs.oracle.com/xuemingshen/entry/zip64_support_for_4g_zipfile"/>
  *
  * @author Gunnar Hillert
  * @author Artem Bilan
@@ -56,9 +56,11 @@ public class ZipTransformer extends AbstractZipTransformer {
 
 	private static final String ZIP_EXTENSION = ".zip";
 
-	private volatile int compressionLevel = Deflater.DEFAULT_COMPRESSION;
+	private int compressionLevel = Deflater.DEFAULT_COMPRESSION;
+
+	private boolean useFileAttributes = true;
 
-	private volatile boolean useFileAttributes = true;
+	private FileNameGenerator fileNameGenerator;
 
 	/**
 	 * Set the compression level. Default is {@link Deflater#DEFAULT_COMPRESSION}.
@@ -77,6 +79,31 @@ public void setUseFileAttributes(boolean useFileAttributes) {
 		this.useFileAttributes = useFileAttributes;
 	}
 
+	/**
+	 * Set a {@link FileNameGenerator} for zip file base name: the {@code .zip} extension is added to this name.
+	 * Unless it already comes with {@code .zip} extension.
+	 * Defaults to the {@link org.springframework.integration.file.DefaultFileNameGenerator}.
+	 * The result of this generator is also used for zip entry(ies) if {@link ZipHeaders#ZIP_ENTRY_FILE_NAME}
+	 * header is not provided in the request message.
+	 * @param fileNameGenerator the {@link FileNameGenerator} to use.
+	 * @since 6.4
+	 */
+	public void setFileNameGenerator(FileNameGenerator fileNameGenerator) {
+		Assert.notNull(fileNameGenerator, "'fileNameGenerator' must not be null");
+		this.fileNameGenerator = fileNameGenerator;
+	}
+
+	@Override
+	protected void onInit() {
+		super.onInit();
+		if (this.fileNameGenerator == null) {
+			DefaultFileNameGenerator defaultFileNameGenerator = new DefaultFileNameGenerator();
+			defaultFileNameGenerator.setBeanFactory(getBeanFactory());
+			defaultFileNameGenerator.setConversionService(getConversionService());
+			this.fileNameGenerator = defaultFileNameGenerator;
+		}
+	}
+
 	/**
 	 * The payload may encompass the following types:
 	 * <ul>
@@ -91,39 +118,19 @@ public void setUseFileAttributes(boolean useFileAttributes) {
 	@Override
 	protected Object doZipTransform(Message<?> message) {
 		Object payload = message.getPayload();
-		Object zippedData;
-		String baseFileName = this.fileNameGenerator.generateFileName(message);
-
-		String zipEntryName;
-		String zipFileName;
+		MessageHeaders messageHeaders = message.getHeaders();
 
-		if (message.getHeaders().containsKey(ZipHeaders.ZIP_ENTRY_FILE_NAME)) {
-			zipEntryName = (String) message.getHeaders().get(ZipHeaders.ZIP_ENTRY_FILE_NAME);
-		}
-		else {
-			zipEntryName = baseFileName;
-		}
-
-		if (message.getHeaders().containsKey(FileHeaders.FILENAME)) {
-			zipFileName = (String) message.getHeaders().get(FileHeaders.FILENAME);
-		}
-		else {
-			zipFileName = baseFileName + ZIP_EXTENSION;
-		}
-
-		Date lastModifiedDate;
+		String baseFileName = this.fileNameGenerator.generateFileName(message);
+		String zipFileName = baseFileName.endsWith(ZIP_EXTENSION) ? baseFileName : baseFileName + ZIP_EXTENSION;
 
-		if (message.getHeaders().containsKey(ZipHeaders.ZIP_ENTRY_LAST_MODIFIED_DATE)) {
-			lastModifiedDate = message.getHeaders().get(ZipHeaders.ZIP_ENTRY_LAST_MODIFIED_DATE, Date.class);
-		}
-		else {
-			lastModifiedDate = new Date();
-		}
+		String zipEntryName = (String) messageHeaders.getOrDefault(ZipHeaders.ZIP_ENTRY_FILE_NAME, baseFileName);
+		Date lastModifiedDate = (Date) messageHeaders.getOrDefault(ZipHeaders.ZIP_ENTRY_LAST_MODIFIED_DATE, new Date());
 
 		List<ZipEntrySource> entries = createZipEntries(payload, zipEntryName, lastModifiedDate);
 
 		byte[] zippedBytes = SpringZipUtils.pack(entries, this.compressionLevel);
 
+		Object zippedData;
 		if (ZipResultType.FILE.equals(this.zipResultType)) {
 			final File zippedFile = new File(this.workDirectory, zipFileName);
 			try {
@@ -145,7 +152,7 @@ else if (ZipResultType.BYTE_ARRAY.equals(this.zipResultType)) {
 
 		return getMessageBuilderFactory()
 				.withPayload(zippedData)
-				.copyHeaders(message.getHeaders())
+				.copyHeaders(messageHeaders)
 				.setHeader(FileHeaders.FILENAME, zipFileName)
 				.build();
 	}

spring-integration-zip/src/test/java/org/springframework/integration/zip/config/xml/UnZipTransformerParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 the original author or authors.
+ * Copyright 2015-2024 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.
@@ -25,8 +25,6 @@
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.integration.channel.AbstractMessageChannel;
 import org.springframework.integration.endpoint.EventDrivenConsumer;
-import org.springframework.integration.file.DefaultFileNameGenerator;
-import org.springframework.integration.file.FileNameGenerator;
 import org.springframework.integration.test.util.TestUtils;
 import org.springframework.integration.transformer.MessageTransformingHandler;
 import org.springframework.integration.zip.transformer.UnZipTransformer;
@@ -64,21 +62,18 @@ public void testUnZipTransformerParserWithDefaults() {
 		final UnZipTransformer unZipTransformer = TestUtils.getPropertyValue(handler, "transformer", UnZipTransformer.class);
 
 		final Charset charset = TestUtils.getPropertyValue(unZipTransformer, "charset", Charset.class);
-		final FileNameGenerator fileNameGenerator = TestUtils.getPropertyValue(unZipTransformer, "fileNameGenerator", FileNameGenerator.class);
 		final ZipResultType zipResultType = TestUtils.getPropertyValue(unZipTransformer, "zipResultType", ZipResultType.class);
 		final File workDirectory = TestUtils.getPropertyValue(unZipTransformer, "workDirectory", File.class);
 		final Boolean deleteFiles = TestUtils.getPropertyValue(unZipTransformer, "deleteFiles", Boolean.class);
 		final Boolean expectSingleResult = TestUtils.getPropertyValue(unZipTransformer, "expectSingleResult", Boolean.class);
 
 		assertThat(charset).isNotNull();
-		assertThat(fileNameGenerator).isNotNull();
 		assertThat(zipResultType).isNotNull();
 		assertThat(workDirectory).isNotNull();
 		assertThat(deleteFiles).isNotNull();
 		assertThat(expectSingleResult).isNotNull();
 
 		assertThat(charset).isEqualTo(Charset.defaultCharset());
-		assertThat(fileNameGenerator).isInstanceOf(DefaultFileNameGenerator.class);
 		assertThat(zipResultType).isEqualTo(ZipResultType.FILE);
 		assertThat(workDirectory)
 				.isEqualTo(new File(System.getProperty("java.io.tmpdir") + File.separator + "ziptransformer"));
@@ -102,21 +97,18 @@ public void testUnZipTransformerParserWithExplicitSettings() {
 		final UnZipTransformer unZipTransformer = TestUtils.getPropertyValue(handler, "transformer", UnZipTransformer.class);
 
 		final Charset charset = TestUtils.getPropertyValue(unZipTransformer, "charset", Charset.class);
-		final FileNameGenerator fileNameGenerator = TestUtils.getPropertyValue(unZipTransformer, "fileNameGenerator", FileNameGenerator.class);
 		final ZipResultType zipResultType = TestUtils.getPropertyValue(unZipTransformer, "zipResultType", ZipResultType.class);
 		final File workDirectory = TestUtils.getPropertyValue(unZipTransformer, "workDirectory", File.class);
 		final Boolean deleteFiles = TestUtils.getPropertyValue(unZipTransformer, "deleteFiles", Boolean.class);
 		final Boolean expectSingleResult = TestUtils.getPropertyValue(unZipTransformer, "expectSingleResult", Boolean.class);
 
 		assertThat(charset).isNotNull();
-		assertThat(fileNameGenerator).isNotNull();
 		assertThat(zipResultType).isNotNull();
 		assertThat(workDirectory).isNotNull();
 		assertThat(deleteFiles).isNotNull();
 		assertThat(expectSingleResult).isNotNull();
 
 		assertThat(charset).isEqualTo(Charset.defaultCharset());
-		assertThat(fileNameGenerator).isInstanceOf(DefaultFileNameGenerator.class);
 		assertThat(zipResultType).isEqualTo(ZipResultType.FILE);
 		assertThat(workDirectory)
 				.isEqualTo(new File(System.getProperty("java.io.tmpdir") + File.separator + "ziptransformer"));

src/reference/antora/modules/ROOT/pages/whats-new.adoc

@@ -78,3 +78,9 @@ See xref:sftp/session-factory.adoc[SFTP Session Factory] for more information.
 Multiple instances of `MqttPahoMessageDrivenChannelAdapter` and `Mqttv5PahoMessageDrivenChannelAdapter` can now be added at runtime using corresponding `ClientManager` through `IntegrationFlowContext`
 Also a `MqttMessageNotDeliveredEvent` event has been introduced to emit when action callback reacts to the delivery failure.
 See xref:mqtt.adoc[MQTT Support] for more information.
+
+[[x6.4-zip-support-changes]]
+=== Zip Support Changes
+
+The `ZipTransformer` now exposes a `fileNameGenerator` property to customize a target zip file (and optional zip entry) name generation.
+See xref:zip.adoc[Zip Support] for more information.

src/reference/antora/modules/ROOT/pages/zip.adoc

@@ -69,6 +69,14 @@ The `ZipTransformer` can be customized by setting several properties:
 Default is `Deflater#DEFAULT_COMPRESSION`.
 
 * `useFileAttributes` - specifies whether the name of the file shall be used for the zip entry.
+* `fileNameGenerator` - uses to generate an original file name based on the request message.
+Defaults to `DefaultFileNameGenerator`.
+The `.zip` extension is added into this name for the target zip file name.
+Unless it is already present as a result of this generator.
+
+In addition, a `ZipHeaders.ZIP_ENTRY_FILE_NAME` and `ZipHeaders.ZIP_ENTRY_LAST_MODIFIED_DATE` can be supplied for the name of zip entry and its `lastmodified` attribute.
+If not provided, the entry name is exact result of the `fileNameGenerator` and `lastmodified` falls back to the current date and time.
+If the payload of request message is an `Iterable`, then this entry name is modified with an index starting `1`.
 
 For example to zip a simple `test.txt` file into a `test.txt.zip`, only this configuration is enough: