FilePart uses correct flags when opening files

Issue: SPR-16546

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -21,7 +21,8 @@ import java.io.File;
 import reactor.core.publisher.Mono;
 
 /**
- * Specialization of {@link Part} for a file upload.
+ * Specialization of {@link Part} that represents an uploaded file received in
+ * a multipart request.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -34,7 +35,9 @@ public interface FilePart extends Part {
 	String filename();
 
 	/**
-	 * Transfer the file in this part to the given file destination.
+	 * Convenience method to copy the content of the file in this part to the
+	 * given destination file. If the destination file already exists, it will
+	 * be truncated first.
 	 * @param dest the target file
 	 * @return completion {@code Mono} with the result of the file transfer,
 	 * possibly {@link IllegalStateException} if the part isn't a file

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

@@ -23,6 +23,7 @@ import java.nio.channels.FileChannel;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.OpenOption;
 import java.nio.file.StandardOpenOption;
 import java.util.Collections;
 import java.util.List;
@@ -279,6 +280,9 @@ public class SynchronossPartHttpMessageReader implements HttpMessageReader<Part>
 
 	private static class SynchronossFilePart extends DefaultSynchronossPart implements FilePart {
 
+		private static final OpenOption[] FILE_CHANNEL_OPTIONS = {
+				StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE };
+
 		private final String filename;
 
 		public SynchronossFilePart(
@@ -299,7 +303,7 @@ public class SynchronossPartHttpMessageReader implements HttpMessageReader<Part>
 			FileChannel output = null;
 			try {
 				input = Channels.newChannel(getStorage().getInputStream());
-				output = FileChannel.open(destination.toPath(), StandardOpenOption.WRITE);
+				output = FileChannel.open(destination.toPath(), FILE_CHANNEL_OPTIONS);
 				long size = (input instanceof FileChannel ? ((FileChannel) input).size() : Long.MAX_VALUE);
 				long totalWritten = 0;
 				while (totalWritten < size) {

spring-web/src/test/java/org/springframework/http/codec/multipart/SynchronossPartHttpMessageReaderTests.java

@@ -16,11 +16,13 @@
 
 package org.springframework.http.codec.multipart;
 
-import java.io.IOException;
+import java.io.File;
+import java.time.Duration;
 import java.util.Map;
 
 import org.junit.Test;
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
 import org.springframework.core.ResolvableType;
@@ -28,25 +30,25 @@ import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.core.io.buffer.DataBufferUtils;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
-import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
-import org.springframework.http.MockHttpOutputMessage;
-import org.springframework.http.converter.FormHttpMessageConverter;
+import org.springframework.http.client.MultipartBodyBuilder;
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.mock.http.client.reactive.test.MockClientHttpRequest;
 import org.springframework.mock.http.server.reactive.test.MockServerHttpRequest;
-import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 
-import static java.util.Collections.emptyMap;
+import static java.util.Collections.*;
 import static org.junit.Assert.*;
-import static org.springframework.core.ResolvableType.forClassWithGenerics;
-import static org.springframework.http.HttpHeaders.CONTENT_LENGTH;
-import static org.springframework.http.HttpHeaders.CONTENT_TYPE;
-import static org.springframework.http.MediaType.MULTIPART_FORM_DATA;
+import static org.springframework.core.ResolvableType.*;
+import static org.springframework.http.HttpHeaders.*;
+import static org.springframework.http.MediaType.*;
 
 /**
+ * Unit tests for {@link SynchronossPartHttpMessageReader}.
+ *
  * @author Sebastien Deleuze
+ * @author Rossen Stoyanchev
  */
 public class SynchronossPartHttpMessageReaderTests {
 
@@ -78,7 +80,7 @@ public class SynchronossPartHttpMessageReaderTests {
 	}
 
 	@Test
-	public void resolveParts() throws IOException {
+	public void resolveParts() {
 		ServerHttpRequest request = generateMultipartRequest();
 		ResolvableType elementType = forClassWithGenerics(MultiValueMap.class, String.class, Part.class);
 		MultiValueMap<String, Part> parts = this.reader.readMono(elementType, request, emptyMap()).block();
@@ -102,6 +104,24 @@ public class SynchronossPartHttpMessageReaderTests {
 		assertEquals("bar", ((FormFieldPart) part).value());
 	}
 
+	@Test // SPR-16545
+	public void transferTo() {
+		ServerHttpRequest request = generateMultipartRequest();
+		ResolvableType elementType = forClassWithGenerics(MultiValueMap.class, String.class, Part.class);
+		MultiValueMap<String, Part> parts = this.reader.readMono(elementType, request, emptyMap()).block();
+
+		assertNotNull(parts);
+		FilePart part = (FilePart) parts.getFirst("fooPart");
+		assertNotNull(part);
+
+		File dest = new File(System.getProperty("java.io.tmpdir") + "/" + part.filename());
+		part.transferTo(dest).block(Duration.ofSeconds(5));
+
+		assertTrue(dest.exists());
+		assertEquals(12, dest.length());
+		assertTrue(dest.delete());
+	}
+
 	@Test
 	public void bodyError() {
 		ServerHttpRequest request = generateErrorMultipartRequest();
@@ -110,29 +130,24 @@ public class SynchronossPartHttpMessageReaderTests {
 	}
 
 
-	private ServerHttpRequest generateMultipartRequest() throws IOException {
-		HttpHeaders fooHeaders = new HttpHeaders();
-		fooHeaders.setContentType(MediaType.TEXT_PLAIN);
-		ClassPathResource fooResource = new ClassPathResource("org/springframework/http/codec/multipart/foo.txt");
-		HttpEntity<ClassPathResource> fooPart = new HttpEntity<>(fooResource, fooHeaders);
-		HttpEntity<String> barPart = new HttpEntity<>("bar");
-		FormHttpMessageConverter converter = new FormHttpMessageConverter();
-		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
-		MultiValueMap<String, Object> parts = new LinkedMultiValueMap<>();
-		parts.add("fooPart", fooPart);
-		parts.add("barPart", barPart);
-		converter.write(parts, MULTIPART_FORM_DATA, outputMessage);
-		byte[] content = outputMessage.getBodyAsBytes();
-		return MockServerHttpRequest
-				.post("/foo")
-				.header(CONTENT_TYPE, outputMessage.getHeaders().getContentType().toString())
-				.header(CONTENT_LENGTH, String.valueOf(content.length))
-				.body(new String(content));
+	private ServerHttpRequest generateMultipartRequest() {
+
+		MultipartBodyBuilder partsBuilder = new MultipartBodyBuilder();
+		partsBuilder.part("fooPart", new ClassPathResource("org/springframework/http/codec/multipart/foo.txt"));
+		partsBuilder.part("barPart", "bar");
+
+		MockClientHttpRequest outputMessage = new MockClientHttpRequest(HttpMethod.POST, "/");
+		new MultipartHttpMessageWriter()
+				.write(Mono.just(partsBuilder.build()), null, MediaType.MULTIPART_FORM_DATA, outputMessage, null)
+				.block(Duration.ofSeconds(5));
+
+		return MockServerHttpRequest.post("/")
+				.contentType(outputMessage.getHeaders().getContentType())
+				.body(outputMessage.getBody());
 	}
 
 	private ServerHttpRequest generateErrorMultipartRequest() {
-		return MockServerHttpRequest
-				.post("/foo")
+		return MockServerHttpRequest.post("/")
 				.header(CONTENT_TYPE, MULTIPART_FORM_DATA.toString())
 				.body(Flux.just(new DefaultDataBufferFactory().wrap("invalid content".getBytes())));
 	}