Support multipart filename with charset

StandardMultipartHttpServletRequest now supports filenames with
charset information.

Issue: SPR-13319

spring-web/src/main/java/org/springframework/web/multipart/support/StandardMultipartHttpServletRequest.java

@@ -20,6 +20,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Serializable;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -44,6 +45,7 @@ import org.springframework.web.multipart.MultipartFile;
  * methods - without any custom processing on our side.
  *
  * @author Juergen Hoeller
+ * @author Rossen Stoyanchev
  * @since 3.1
  */
 public class StandardMultipartHttpServletRequest extends AbstractMultipartHttpServletRequest {
@@ -52,6 +54,11 @@ public class StandardMultipartHttpServletRequest extends AbstractMultipartHttpSe
 
 	private static final String FILENAME_KEY = "filename=";
 
+	private static final String FILENAME_WITH_CHARSET_KEY = "filename*=";
+
+	private static final Charset US_ASCII = Charset.forName("us-ascii");
+
+
 	private Set<String> multipartParameterNames;
 
 
@@ -86,7 +93,11 @@ public class StandardMultipartHttpServletRequest extends AbstractMultipartHttpSe
 			this.multipartParameterNames = new LinkedHashSet<String>(parts.size());
 			MultiValueMap<String, MultipartFile> files = new LinkedMultiValueMap<String, MultipartFile>(parts.size());
 			for (Part part : parts) {
-				String filename = extractFilename(part.getHeader(CONTENT_DISPOSITION));
+				String disposition = part.getHeader(CONTENT_DISPOSITION);
+				String filename = extractFilename(disposition);
+				if (filename == null) {
+					filename = extractFilenameWithCharset(disposition);
+				}
 				if (filename != null) {
 					files.add(part.getName(), new StandardMultipartFile(part, filename));
 				}
@@ -102,15 +113,18 @@ public class StandardMultipartHttpServletRequest extends AbstractMultipartHttpSe
 	}
 
 	private String extractFilename(String contentDisposition) {
+		return extractFilename(contentDisposition, FILENAME_KEY);
+	}
+
+	private String extractFilename(String contentDisposition, String key) {
 		if (contentDisposition == null) {
 			return null;
 		}
-		// TODO: can only handle the typical case at the moment
-		int startIndex = contentDisposition.indexOf(FILENAME_KEY);
+		int startIndex = contentDisposition.indexOf(key);
 		if (startIndex == -1) {
 			return null;
 		}
-		String filename = contentDisposition.substring(startIndex + FILENAME_KEY.length());
+		String filename = contentDisposition.substring(startIndex + key.length());
 		if (filename.startsWith("\"")) {
 			int endIndex = filename.indexOf("\"", 1);
 			if (endIndex != -1) {
@@ -126,6 +140,33 @@ public class StandardMultipartHttpServletRequest extends AbstractMultipartHttpSe
 		return filename;
 	}
 
+	private String extractFilenameWithCharset(String contentDisposition) {
+		String filename = extractFilename(contentDisposition, FILENAME_WITH_CHARSET_KEY);
+		if (filename == null) {
+			return null;
+		}
+		int index = filename.indexOf("'");
+		if (index != -1) {
+			Charset charset = null;
+			try {
+				charset = Charset.forName(filename.substring(0, index));
+			}
+			catch (IllegalArgumentException ex) {
+				// ignore
+			}
+			filename = filename.substring(index + 1);
+			// Skip language information..
+			index = filename.indexOf("'");
+			if (index != -1) {
+				filename = filename.substring(index + 1);
+			}
+			if (charset != null) {
+				filename = new String(filename.getBytes(US_ASCII), charset);
+			}
+		}
+		return filename;
+	}
+
 
 	@Override
 	protected void initializeMultipart() {

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestPartIntegrationTests.java

@@ -19,9 +19,9 @@ package org.springframework.web.servlet.mvc.method.annotation;
 import java.net.URI;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
-
+import java.util.Map;
 import javax.servlet.MultipartConfigElement;
 
 import org.eclipse.jetty.server.Connector;
@@ -29,7 +29,6 @@ import org.eclipse.jetty.server.NetworkConnector;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
-
 import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.Before;
@@ -43,6 +42,7 @@ import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.http.converter.ByteArrayHttpMessageConverter;
@@ -52,9 +52,9 @@ import org.springframework.http.converter.json.MappingJackson2HttpMessageConvert
 import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
 import org.springframework.stereotype.Controller;
 import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestPart;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
@@ -66,7 +66,8 @@ import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.springframework.web.bind.annotation.RequestMethod.POST;
 
 /**
  * Test access to parts of a multipart request with {@link RequestPart}.
@@ -117,7 +118,7 @@ public class RequestPartIntegrationTests {
 	@Before
 	public void setUp() {
 		ByteArrayHttpMessageConverter emptyBodyConverter = new ByteArrayHttpMessageConverter();
-		emptyBodyConverter.setSupportedMediaTypes(Arrays.asList(MediaType.APPLICATION_JSON));
+		emptyBodyConverter.setSupportedMediaTypes(Collections.singletonList(MediaType.APPLICATION_JSON));
 
 		List<HttpMessageConverter<?>> converters = new ArrayList<>(3);
 		converters.add(emptyBodyConverter);
@@ -129,7 +130,7 @@ public class RequestPartIntegrationTests {
 		converter.setPartConverters(converters);
 
 		restTemplate = new RestTemplate(new HttpComponentsClientHttpRequestFactory());
-		restTemplate.setMessageConverters(Arrays.<HttpMessageConverter<?>>asList(converter));
+		restTemplate.setMessageConverters(Collections.singletonList(converter));
 	}
 
 	@AfterClass
@@ -150,6 +151,37 @@ public class RequestPartIntegrationTests {
 		testCreate(baseUrl + "/standard-resolver/test");
 	}
 
+	// SPR-13319
+
+	@Test
+	public void standardMultipartResolverWithEncodedFileName() throws Exception {
+
+		byte[] boundary = MimeTypeUtils.generateMultipartBoundary();
+		String boundaryText = new String(boundary, "US-ASCII");
+		Map<String, String> params = Collections.singletonMap("boundary", boundaryText);
+
+		String content =
+				"--" + boundaryText + "\n" +
+				"Content-Disposition: form-data; name=\"file\"; filename*=\"utf-8''%C3%A9l%C3%A8ve.txt\"\n" +
+				"Content-Type: text/plain\n" +
+				"Content-Length: 7\n" +
+				"\n" +
+				"content\n" +
+				"--" + boundaryText + "--";
+
+		RequestEntity<byte[]> requestEntity =
+				RequestEntity.post(new URI(baseUrl + "/standard-resolver/spr13319"))
+						.contentType(new MediaType(MediaType.MULTIPART_FORM_DATA, params))
+						.body(content.getBytes(Charset.forName("us-ascii")));
+
+		ByteArrayHttpMessageConverter converter = new ByteArrayHttpMessageConverter();
+		converter.setSupportedMediaTypes(Collections.singletonList(MediaType.MULTIPART_FORM_DATA));
+		this.restTemplate.setMessageConverters(Collections.singletonList(converter));
+
+		ResponseEntity<Void> responseEntity = restTemplate.exchange(requestEntity, Void.class);
+		assertEquals(HttpStatus.OK, responseEntity.getStatusCode());
+	}
+
 	private void testCreate(String url) {
 		MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
 		parts.add("json-data", new HttpEntity<TestData>(new TestData("Jason")));
@@ -176,6 +208,7 @@ public class RequestPartIntegrationTests {
 	}
 
 	@Configuration
+	@SuppressWarnings("unused")
 	static class CommonsMultipartResolverTestConfig extends RequestPartTestConfig {
 
 		@Bean
@@ -185,6 +218,7 @@ public class RequestPartIntegrationTests {
 	}
 
 	@Configuration
+	@SuppressWarnings("unused")
 	static class StandardMultipartResolverTestConfig extends RequestPartTestConfig {
 
 		@Bean
@@ -194,9 +228,10 @@ public class RequestPartIntegrationTests {
 	}
 
 	@Controller
+	@SuppressWarnings("unused")
 	private static class RequestPartTestController {
 
-		@RequestMapping(value = "/test", method = RequestMethod.POST, consumes = { "multipart/mixed", "multipart/form-data" })
+		@RequestMapping(value = "/test", method = POST, consumes = { "multipart/mixed", "multipart/form-data" })
 		public ResponseEntity<Object> create(@RequestPart(name = "json-data") TestData testData,
 				@RequestPart("file-data") MultipartFile file,
 				@RequestPart(name = "empty-data", required = false) TestData emptyData,
@@ -209,6 +244,12 @@ public class RequestPartIntegrationTests {
 			headers.setLocation(URI.create(url));
 			return new ResponseEntity<Object>(headers, HttpStatus.CREATED);
 		}
+
+		@RequestMapping(value = "/spr13319", method = POST, consumes = "multipart/form-data")
+		public ResponseEntity<Void> create(@RequestPart("file") MultipartFile multipartFile) {
+			assertEquals("%C3%A9l%C3%A8ve.txt", multipartFile.getOriginalFilename());
+			return ResponseEntity.ok().build();
+		}
 	}
 
 	@SuppressWarnings("unused")