ResourceDecoder supports filename hint

Closes gh-22267

spring-core/src/main/java/org/springframework/core/codec/ResourceDecoder.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -41,6 +41,10 @@ import org.springframework.util.MimeTypeUtils;
  */
 public class ResourceDecoder extends AbstractDataBufferDecoder<Resource> {
 
+	/** Name of hint with a filename for the resource(e.g. from "Content-Disposition" HTTP header). */
+	public static String FILENAME_HINT = ResourceDecoder.class.getName() + ".filename";
+
+
 	public ResourceDecoder() {
 		super(MimeTypeUtils.ALL);
 	}
@@ -72,11 +76,22 @@ public class ResourceDecoder extends AbstractDataBufferDecoder<Resource> {
 		}
 
 		Class<?> clazz = elementType.toClass();
+		String filename = hints != null ? (String) hints.get(FILENAME_HINT) : null;
 		if (clazz == InputStreamResource.class) {
-			return new InputStreamResource(new ByteArrayInputStream(bytes));
+			return new InputStreamResource(new ByteArrayInputStream(bytes)) {
+				@Override
+				public String getFilename() {
+					return filename;
+				}
+			};
 		}
 		else if (Resource.class.isAssignableFrom(clazz)) {
-			return new ByteArrayResource(bytes);
+			return new ByteArrayResource(bytes) {
+				@Override
+				public String getFilename() {
+					return filename;
+				}
+			};
 		}
 		else {
 			throw new IllegalStateException("Unsupported resource class: " + clazz);

spring-core/src/test/java/org/springframework/core/codec/ResourceDecoderTests.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -18,6 +18,7 @@ package org.springframework.core.codec;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.util.Collections;
 import java.util.Map;
 
 import org.junit.Test;
@@ -100,23 +101,28 @@ public class ResourceDecoderTests extends AbstractDecoderTestCase<ResourceDecode
 	}
 
 	@Override
-	public void decodeToMono() throws Exception {
+	public void decodeToMono() {
 		Flux<DataBuffer> input = Flux.concat(
 				dataBuffer(this.fooBytes),
 				dataBuffer(this.barBytes));
 
-		testDecodeToMonoAll(input, Resource.class, step -> step
-				.consumeNextWith(resource -> {
-					try {
-						byte[] bytes = StreamUtils.copyToByteArray(resource.getInputStream());
-						assertEquals("foobar", new String(bytes));
-					}
-					catch (IOException e) {
-						fail(e.getMessage());
-					}
-				})
-				.expectComplete()
-				.verify());
+		testDecodeToMonoAll(input, ResolvableType.forClass(Resource.class),
+				step -> step
+						.consumeNextWith(value -> {
+							Resource resource = (Resource) value;
+							try {
+								byte[] bytes = StreamUtils.copyToByteArray(resource.getInputStream());
+								assertEquals("foobar", new String(bytes));
+								assertEquals("testFile", resource.getFilename());
+							}
+							catch (IOException e) {
+								fail(e.getMessage());
+							}
+						})
+						.expectComplete()
+						.verify(),
+				null,
+				Collections.singletonMap(ResourceDecoder.FILENAME_HINT, "testFile"));
 	}
 
 }

spring-web/src/main/java/org/springframework/http/codec/ResourceHttpMessageReader.java

+/*
+ * Copyright 2002-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.http.codec;
+
+import java.util.Map;
+
+import org.springframework.core.ResolvableType;
+import org.springframework.core.codec.Hints;
+import org.springframework.core.codec.ResourceDecoder;
+import org.springframework.core.io.Resource;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.util.StringUtils;
+
+/**
+ * Simple around around {@link ResourceDecoder} that extracts the filename from
+ * the "Content-Disposition" header, if available, and passes it as the hint
+ * {@link ResourceDecoder#FILENAME_HINT}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 5.2
+ */
+public class ResourceHttpMessageReader extends DecoderHttpMessageReader<Resource> {
+
+
+	public ResourceHttpMessageReader() {
+		super(new ResourceDecoder());
+	}
+
+	public ResourceHttpMessageReader(ResourceDecoder resourceDecoder) {
+		super(resourceDecoder);
+	}
+
+
+	@Override
+	protected Map<String, Object> getReadHints(ResolvableType actualType, ResolvableType elementType,
+			ServerHttpRequest request, ServerHttpResponse response) {
+
+		String name = request.getHeaders().getContentDisposition().getFilename();
+		return StringUtils.hasText(name) ? Hints.from(ResourceDecoder.FILENAME_HINT, name) : Hints.none();
+	}
+
+}

spring-web/src/main/java/org/springframework/http/codec/support/BaseDefaultCodecs.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -29,7 +29,6 @@ import org.springframework.core.codec.DataBufferDecoder;
 import org.springframework.core.codec.DataBufferEncoder;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
-import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.http.codec.CodecConfigurer;
 import org.springframework.http.codec.DecoderHttpMessageReader;
@@ -37,6 +36,7 @@ import org.springframework.http.codec.EncoderHttpMessageWriter;
 import org.springframework.http.codec.FormHttpMessageReader;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageReader;
 import org.springframework.http.codec.ResourceHttpMessageWriter;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
@@ -158,7 +158,7 @@ class BaseDefaultCodecs implements CodecConfigurer.DefaultCodecs {
 		readers.add(new DecoderHttpMessageReader<>(new ByteArrayDecoder()));
 		readers.add(new DecoderHttpMessageReader<>(new ByteBufferDecoder()));
 		readers.add(new DecoderHttpMessageReader<>(new DataBufferDecoder()));
-		readers.add(new DecoderHttpMessageReader<>(new ResourceDecoder()));
+		readers.add(new ResourceHttpMessageReader());
 		readers.add(new DecoderHttpMessageReader<>(StringDecoder.textPlainOnly()));
 		if (protobufPresent) {
 			Decoder<?> decoder = this.protobufDecoder != null ? this.protobufDecoder : new ProtobufDecoder();

spring-web/src/test/java/org/springframework/http/codec/support/ClientCodecConfigurerTests.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -36,7 +36,6 @@ import org.springframework.core.codec.DataBufferDecoder;
 import org.springframework.core.codec.DataBufferEncoder;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
-import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.MediaType;
@@ -46,6 +45,7 @@ import org.springframework.http.codec.EncoderHttpMessageWriter;
 import org.springframework.http.codec.FormHttpMessageReader;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageReader;
 import org.springframework.http.codec.ResourceHttpMessageWriter;
 import org.springframework.http.codec.ServerSentEventHttpMessageReader;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
@@ -60,7 +60,7 @@ import org.springframework.http.codec.xml.Jaxb2XmlEncoder;
 import org.springframework.util.MimeTypeUtils;
 
 import static org.junit.Assert.*;
-import static org.springframework.core.ResolvableType.forClass;
+import static org.springframework.core.ResolvableType.*;
 
 /**
  * Unit tests for {@link ClientCodecConfigurer}.
@@ -81,7 +81,7 @@ public class ClientCodecConfigurerTests {
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ByteBufferDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(DataBufferDecoder.class, getNextDecoder(readers).getClass());
-		assertEquals(ResourceDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(ResourceHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
 		assertStringDecoder(getNextDecoder(readers), true);
 		assertEquals(ProtobufDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(FormHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass()); // SPR-16804

spring-web/src/test/java/org/springframework/http/codec/support/CodecConfigurerTests.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -32,7 +32,6 @@ import org.springframework.core.codec.DataBufferDecoder;
 import org.springframework.core.codec.DataBufferEncoder;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
-import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.http.MediaType;
 import org.springframework.http.codec.CodecConfigurer;
@@ -41,6 +40,7 @@ import org.springframework.http.codec.EncoderHttpMessageWriter;
 import org.springframework.http.codec.FormHttpMessageReader;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageReader;
 import org.springframework.http.codec.ResourceHttpMessageWriter;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
@@ -76,7 +76,7 @@ public class CodecConfigurerTests {
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ByteBufferDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(DataBufferDecoder.class, getNextDecoder(readers).getClass());
-		assertEquals(ResourceDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(ResourceHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
 		assertStringDecoder(getNextDecoder(readers), true);
 		assertEquals(ProtobufDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(FormHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
@@ -128,7 +128,7 @@ public class CodecConfigurerTests {
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ByteBufferDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(DataBufferDecoder.class, getNextDecoder(readers).getClass());
-		assertEquals(ResourceDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(ResourceHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
 		assertEquals(StringDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ProtobufDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(FormHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());

spring-web/src/test/java/org/springframework/http/codec/support/ServerCodecConfigurerTests.java

 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -36,7 +36,6 @@ import org.springframework.core.codec.DataBufferDecoder;
 import org.springframework.core.codec.DataBufferEncoder;
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
-import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.MediaType;
@@ -45,6 +44,7 @@ import org.springframework.http.codec.EncoderHttpMessageWriter;
 import org.springframework.http.codec.FormHttpMessageReader;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageReader;
 import org.springframework.http.codec.ResourceHttpMessageWriter;
 import org.springframework.http.codec.ServerCodecConfigurer;
 import org.springframework.http.codec.ServerSentEventHttpMessageWriter;
@@ -61,7 +61,7 @@ import org.springframework.http.codec.xml.Jaxb2XmlEncoder;
 import org.springframework.util.MimeTypeUtils;
 
 import static org.junit.Assert.*;
-import static org.springframework.core.ResolvableType.forClass;
+import static org.springframework.core.ResolvableType.*;
 
 /**
  * Unit tests for {@link ServerCodecConfigurer}.
@@ -82,7 +82,7 @@ public class ServerCodecConfigurerTests {
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ByteBufferDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(DataBufferDecoder.class, getNextDecoder(readers).getClass());
-		assertEquals(ResourceDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(ResourceHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
 		assertStringDecoder(getNextDecoder(readers), true);
 		assertEquals(ProtobufDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(FormHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());