Fix error in mock server test code

Author: rstoyanchev

spring-web/src/test/java/org/springframework/web/client/AbstractMockWebServerTestCase.java

@@ -121,9 +121,9 @@ private MockResponse jsonPostRequest(RecordedRequest request, String location, S
 	}
 
 	private MockResponse multipartRequest(RecordedRequest request) {
-		String contentType = request.getHeader("Content-Type");
-		assertTrue(contentType.startsWith("multipart/form-data"));
-		String boundary = contentType.split("boundary=")[1];
+		MediaType mediaType = MediaType.parseMediaType(request.getHeader("Content-Type"));
+		assertTrue(mediaType.isCompatibleWith(MediaType.MULTIPART_FORM_DATA));
+		String boundary = mediaType.getParameter("boundary");
 		Buffer body = request.getBody();
 		try {
 			assertPart(body, "form-data", boundary, "name 1", "text/plain", "value 1");

spring-web/src/test/resources/log4j2-test.xml

@@ -6,7 +6,7 @@
 		</Console>
 	</Appenders>
 	<Loggers>
-		<Logger name="org.springframework.web" level="warn" />
+		<Logger name="org.springframework.web" level="debug" />
 		<Logger name="org.springframework.beans" level="warn" />
 		<Logger name="org.springframework.binding" level="warn" />
 		<Logger name="org.springframework.http" level="warn" />