Remove spring.webflux.multipart.streaming property

As of spring-projects/spring-framework#29293, the streaming mode on the
`DefaultPartHttpMessageReader` is deprecated as hard limitations have
been found with the design and won't be fixed. Instead, developers
should use the `PartEvent` API and the `PartEventHttpMessageReader`
(which is configured by default with the codecs).

This commit removes the `spring.webflux.multipart.streaming` property
and applies all `spring.webflux.multipart.*` properties that are
applicable to `PartEventHttpMessageReader`.

Closes gh-32658

Author: bclozel

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/ReactiveMultipartAutoConfiguration.java

@@ -31,6 +31,7 @@
 import org.springframework.context.annotation.Bean;
 import org.springframework.core.annotation.Order;
 import org.springframework.http.codec.multipart.DefaultPartHttpMessageReader;
+import org.springframework.http.codec.multipart.PartEventHttpMessageReader;
 import org.springframework.util.unit.DataSize;
 import org.springframework.web.reactive.config.WebFluxConfigurer;
 
@@ -61,11 +62,18 @@ CodecCustomizer defaultPartHttpMessageReaderCustomizer(ReactiveMultipartProperti
 				map.from(multipartProperties::getMaxDiskUsagePerPart).asInt(DataSize::toBytes)
 						.to(defaultPartHttpMessageReader::setMaxDiskUsagePerPart);
 				map.from(multipartProperties::getMaxParts).to(defaultPartHttpMessageReader::setMaxParts);
-				map.from(multipartProperties::getStreaming).to(defaultPartHttpMessageReader::setStreaming);
 				map.from(multipartProperties::getFileStorageDirectory).as(Paths::get)
 						.to((dir) -> configureFileStorageDirectory(defaultPartHttpMessageReader, dir));
 				map.from(multipartProperties::getHeadersCharset).to(defaultPartHttpMessageReader::setHeadersCharset);
 			}
+			else if (codec instanceof PartEventHttpMessageReader partEventHttpMessageReader) {
+				PropertyMapper map = PropertyMapper.get().alwaysApplyingWhenNonNull();
+				map.from(multipartProperties::getMaxInMemorySize).asInt(DataSize::toBytes)
+						.to(partEventHttpMessageReader::setMaxInMemorySize);
+				map.from(multipartProperties::getMaxHeadersSize).asInt(DataSize::toBytes)
+						.to(partEventHttpMessageReader::setMaxHeadersSize);
+				map.from(multipartProperties::getHeadersCharset).to(partEventHttpMessageReader::setHeadersCharset);
+			}
 		});
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/ReactiveMultipartProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -21,11 +21,13 @@
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.http.codec.multipart.DefaultPartHttpMessageReader;
+import org.springframework.http.codec.multipart.PartEventHttpMessageReader;
 import org.springframework.util.unit.DataSize;
 
 /**
  * {@link ConfigurationProperties Configuration properties} for configuring multipart
- * support in Spring Webflux. Used to configure the {@link DefaultPartHttpMessageReader}.
+ * support in Spring Webflux. Used to configure the {@link DefaultPartHttpMessageReader}
+ * and the {@link PartEventHttpMessageReader}.
  *
  * @author Chris Bono
  * @since 2.6.0
@@ -57,12 +59,6 @@ public class ReactiveMultipartProperties {
 	 */
 	private Integer maxParts = -1;
 
-	/**
-	 * Whether to stream directly from the parsed input buffer stream without storing in
-	 * memory nor file. Default is non-streaming.
-	 */
-	private Boolean streaming = Boolean.FALSE;
-
 	/**
 	 * Directory used to store file parts larger than 'maxInMemorySize'. Default is a
 	 * directory named 'spring-multipart' created under the system temporary directory.
@@ -107,14 +103,6 @@ public void setMaxParts(Integer maxParts) {
 		this.maxParts = maxParts;
 	}
 
-	public Boolean getStreaming() {
-		return this.streaming;
-	}
-
-	public void setStreaming(Boolean streaming) {
-		this.streaming = streaming;
-	}
-
 	public String getFileStorageDirectory() {
 		return this.fileStorageDirectory;
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -3376,6 +3376,14 @@
           "name": "any"
         }
       ]
+    },
+    {
+      "name": "spring.webflux.multipart.streaming",
+      "type": "java.lang.Boolean",
+      "deprecation": {
+        "reason": "Replaced by the PartEventHttpMessageReader and the PartEvent API.",
+        "level": "error"
+      }
     }
   ]
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/reactive/ReactiveMultipartAutoConfigurationTests.java

@@ -26,6 +26,7 @@
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.boot.web.codec.CodecCustomizer;
 import org.springframework.http.codec.multipart.DefaultPartHttpMessageReader;
+import org.springframework.http.codec.multipart.PartEventHttpMessageReader;
 import org.springframework.http.codec.support.DefaultServerCodecConfigurer;
 import org.springframework.util.unit.DataSize;
 import org.springframework.web.reactive.config.WebFluxConfigurer;
@@ -36,6 +37,7 @@
  * Tests for {@link ReactiveMultipartAutoConfiguration}.
  *
  * @author Chris Bono
+ * @author Brian Clozel
  */
 class ReactiveMultipartAutoConfigurationTests {
 
@@ -56,16 +58,17 @@ void shouldNotProvideCustomizerWhenWebFluxNotAvailable() {
 	}
 
 	@Test
-	void shouldConfigureMultipartProperties() {
-		this.contextRunner.withPropertyValues("spring.webflux.multipart.streaming:true",
-				"spring.webflux.multipart.max-in-memory-size=1GB", "spring.webflux.multipart.max-headers-size=16KB",
-				"spring.webflux.multipart.max-disk-usage-per-part=100MB", "spring.webflux.multipart.max-parts=7",
-				"spring.webflux.multipart.headers-charset:UTF_16").run((context) -> {
+	void shouldConfigureMultipartPropertiesForDefaultReader() {
+		this.contextRunner
+				.withPropertyValues("spring.webflux.multipart.max-in-memory-size=1GB",
+						"spring.webflux.multipart.max-headers-size=16KB",
+						"spring.webflux.multipart.max-disk-usage-per-part=100MB",
+						"spring.webflux.multipart.max-parts=7", "spring.webflux.multipart.headers-charset:UTF_16")
+				.run((context) -> {
 					CodecCustomizer customizer = context.getBean(CodecCustomizer.class);
 					DefaultServerCodecConfigurer configurer = new DefaultServerCodecConfigurer();
 					customizer.customize(configurer);
-					DefaultPartHttpMessageReader partReader = getPartReader(configurer);
-					assertThat(partReader).hasFieldOrPropertyWithValue("streaming", true);
+					DefaultPartHttpMessageReader partReader = getDefaultPartReader(configurer);
 					assertThat(partReader).hasFieldOrPropertyWithValue("maxParts", 7);
 					assertThat(partReader).hasFieldOrPropertyWithValue("maxHeadersSize",
 							Math.toIntExact(DataSize.ofKilobytes(16).toBytes()));
@@ -77,10 +80,33 @@ void shouldConfigureMultipartProperties() {
 				});
 	}
 
-	private DefaultPartHttpMessageReader getPartReader(DefaultServerCodecConfigurer codecConfigurer) {
+	@Test
+	void shouldConfigureMultipartPropertiesForPartEventReader() {
+		this.contextRunner.withPropertyValues("spring.webflux.multipart.max-in-memory-size=1GB",
+				"spring.webflux.multipart.max-headers-size=16KB", "spring.webflux.multipart.headers-charset:UTF_16")
+				.run((context) -> {
+					CodecCustomizer customizer = context.getBean(CodecCustomizer.class);
+					DefaultServerCodecConfigurer configurer = new DefaultServerCodecConfigurer();
+					customizer.customize(configurer);
+					PartEventHttpMessageReader partReader = getPartEventReader(configurer);
+					assertThat(partReader).hasFieldOrPropertyWithValue("maxHeadersSize",
+							Math.toIntExact(DataSize.ofKilobytes(16).toBytes()));
+					assertThat(partReader).hasFieldOrPropertyWithValue("headersCharset", StandardCharsets.UTF_16);
+					assertThat(partReader).hasFieldOrPropertyWithValue("maxInMemorySize",
+							Math.toIntExact(DataSize.ofGigabytes(1).toBytes()));
+				});
+	}
+
+	private DefaultPartHttpMessageReader getDefaultPartReader(DefaultServerCodecConfigurer codecConfigurer) {
 		return codecConfigurer.getReaders().stream().filter(DefaultPartHttpMessageReader.class::isInstance)
 				.map(DefaultPartHttpMessageReader.class::cast).findFirst()
 				.orElseThrow(() -> new IllegalStateException("Could not find DefaultPartHttpMessageReader"));
 	}
 
+	private PartEventHttpMessageReader getPartEventReader(DefaultServerCodecConfigurer codecConfigurer) {
+		return codecConfigurer.getReaders().stream().filter(PartEventHttpMessageReader.class::isInstance)
+				.map(PartEventHttpMessageReader.class::cast).findFirst()
+				.orElseThrow(() -> new IllegalStateException("Could not find PartEventHttpMessageReader"));
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/reactive/ReactiveMultipartPropertiesTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -33,8 +33,6 @@ class ReactiveMultipartPropertiesTests {
 	void defaultValuesAreConsistent() {
 		ReactiveMultipartProperties multipartProperties = new ReactiveMultipartProperties();
 		DefaultPartHttpMessageReader defaultPartHttpMessageReader = new DefaultPartHttpMessageReader();
-		assertThat(defaultPartHttpMessageReader).hasFieldOrPropertyWithValue("streaming",
-				multipartProperties.getStreaming());
 		assertThat(defaultPartHttpMessageReader).hasFieldOrPropertyWithValue("maxInMemorySize",
 				(int) multipartProperties.getMaxInMemorySize().toBytes());
 		assertThat(defaultPartHttpMessageReader).hasFieldOrPropertyWithValue("maxHeadersSize",