SPR-6247 - Multipart Content-Type charset is ignored in CommonsFileUploadSupport.

org.springframework.web/src/main/java/org/springframework/web/multipart/commons/CommonsFileUploadSupport.java

@@ -22,6 +22,7 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.nio.charset.Charset;
 
 import org.apache.commons.fileupload.FileItem;
 import org.apache.commons.fileupload.FileItemFactory;
@@ -36,6 +37,7 @@ import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.util.WebUtils;
+import org.springframework.http.MediaType;
 
 /**
  * Base class for multipart resolvers that use Jakarta Commons FileUpload
@@ -221,14 +223,15 @@ public abstract class CommonsFileUploadSupport {
 		for (FileItem fileItem : fileItems) {
 			if (fileItem.isFormField()) {
 				String value;
-				if (encoding != null) {
+				String partEncoding = determineEncoding(fileItem.getContentType(), encoding);
+				if (partEncoding != null) {
 					try {
-						value = fileItem.getString(encoding);
+						value = fileItem.getString(partEncoding);
 					}
 					catch (UnsupportedEncodingException ex) {
 						if (logger.isWarnEnabled()) {
 							logger.warn("Could not decode multipart item '" + fileItem.getFieldName() +
-									"' with encoding '" + encoding + "': using platform default");
+									"' with encoding '" + partEncoding + "': using platform default");
 						}
 						value = fileItem.getString();
 					}
@@ -281,6 +284,15 @@ public abstract class CommonsFileUploadSupport {
 		}
 	}
 
+	private String determineEncoding(String contentTypeHeader, String defaultEncoding) {
+		if (!StringUtils.hasText(contentTypeHeader)) {
+			return defaultEncoding;
+		}
+		MediaType contentType = MediaType.parseMediaType(contentTypeHeader);
+		Charset charset = contentType.getCharSet();
+		return charset != null ? charset.name() : defaultEncoding;
+	}
+
 
 	/**
 	 * Holder for a Map of Spring MultipartFiles and a Map of

org.springframework.web/src/test/java/org/springframework/http/MediaTypeTests.java

@@ -19,6 +19,7 @@ package org.springframework.http;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.nio.charset.Charset;
 
 import static org.junit.Assert.*;
 import org.junit.Test;
@@ -55,6 +56,15 @@ public class MediaTypeTests {
 		assertEquals("Invalid quality factor", 0.2D, mediaType.getQualityValue(), 0D);
 	}
 
+	@Test
+	public void parseCharset() throws Exception {
+		String s = "text/html; charset=iso-8859-1";
+		MediaType mediaType = MediaType.parseMediaType(s);
+		assertEquals("Invalid type", "text", mediaType.getType());
+		assertEquals("Invalid subtype", "html", mediaType.getSubtype());
+		assertEquals("Invalid charset", Charset.forName("ISO-8859-1"), mediaType.getCharSet());
+	}
+
 	@Test
 	public void parseURLConnectionMediaType() throws Exception {
 		String s = "*; q=.2";

org.springframework.web/src/test/java/org/springframework/web/multipart/commons/CommonsMultipartResolverTests.java

@@ -375,7 +375,7 @@ public class CommonsMultipartResolverTests {
 					MockFileItem fileItem2x = new MockFileItem(
 					    "field2x", "type2", empty ? "" : "C:\\field2x.txt", empty ? "" : "text2");
 					MockFileItem fileItem3 = new MockFileItem("field3", null, null, "value3");
-					MockFileItem fileItem4 = new MockFileItem("field4", null, null, "value4");
+					MockFileItem fileItem4 = new MockFileItem("field4", "text/html; charset=iso-8859-1", null, "value4");
 					MockFileItem fileItem5 = new MockFileItem("field4", null, null, "value5");
 					fileItems.add(fileItem1);
 					fileItems.add(fileItem1x);