diff --git a/spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java b/spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java
index a48ae62901f..62137f0e66f 100644
--- a/spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java
+++ b/spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java
@@ -742,6 +742,13 @@ public class MockHttpServletResponse implements HttpServletResponse {
 			super.flush();
 			setCommitted(true);
 		}
+
+		@Override
+		public void close() {
+			super.flush();
+			super.close();
+			setCommitted(true);
+		}
 	}
 
 }
diff --git a/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java b/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java
index 0b5ca7eaaf8..078e689eb82 100644
--- a/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java
+++ b/spring-test/src/test/java/org/springframework/mock/web/MockHttpServletResponseTests.java
@@ -227,6 +227,16 @@ public class MockHttpServletResponseTests {
 		assertEquals(1, response.getContentAsByteArray().length);
 	}
 
+	@Test // SPR-16683
+	public void servletWriterCommittedOnWriterClose() throws IOException {
+		assertFalse(response.isCommitted());
+		response.getWriter().write("X");
+		assertFalse(response.isCommitted());
+		response.getWriter().close();
+		assertTrue(response.isCommitted());
+		assertEquals(1, response.getContentAsByteArray().length);
+	}
+
 	@Test
 	public void servletWriterAutoFlushedForString() throws IOException {
 		response.getWriter().write("X");
diff --git a/spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java b/spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java
index 727faafd0c7..48001545c0e 100644
--- a/spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java
+++ b/spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java
@@ -40,6 +40,7 @@ import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedCaseInsensitiveMap;
 import org.springframework.util.StringUtils;
@@ -72,6 +73,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 
 	private boolean writerAccessAllowed = true;
 
+	@Nullable
 	private String characterEncoding = WebUtils.DEFAULT_CHARACTER_ENCODING;
 
 	private boolean charset = false;
@@ -80,10 +82,12 @@ public class MockHttpServletResponse implements HttpServletResponse {
 
 	private final ServletOutputStream outputStream = new ResponseServletOutputStream(this.content);
 
+	@Nullable
 	private PrintWriter writer;
 
 	private long contentLength = 0;
 
+	@Nullable
 	private String contentType;
 
 	private int bufferSize = 4096;
@@ -103,8 +107,10 @@ public class MockHttpServletResponse implements HttpServletResponse {
 
 	private int status = HttpServletResponse.SC_OK;
 
+	@Nullable
 	private String errorMessage;
 
+	@Nullable
 	private String forwardedUrl;
 
 	private final List<String> includedUrls = new ArrayList<>();
@@ -170,6 +176,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	@Override
+	@Nullable
 	public String getCharacterEncoding() {
 		return this.characterEncoding;
 	}
@@ -221,7 +228,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	@Override
-	public void setContentType(String contentType) {
+	public void setContentType(@Nullable String contentType) {
 		this.contentType = contentType;
 		if (contentType != null) {
 			try {
@@ -244,6 +251,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	@Override
+	@Nullable
 	public String getContentType() {
 		return this.contentType;
 	}
@@ -352,6 +360,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 		return this.cookies.toArray(new Cookie[0]);
 	}
 
+	@Nullable
 	public Cookie getCookie(String name) {
 		Assert.notNull(name, "Cookie name must not be null");
 		for (Cookie cookie : this.cookies) {
@@ -387,6 +396,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 * @return the associated header value, or {@code null} if none
 	 */
 	@Override
+	@Nullable
 	public String getHeader(String name) {
 		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
 		return (header != null ? header.getStringValue() : null);
@@ -417,6 +427,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 * @param name the name of the header
 	 * @return the associated header value, or {@code null} if none
 	 */
+	@Nullable
 	public Object getHeaderValue(String name) {
 		HeaderValueHolder header = HeaderValueHolder.getByName(this.headers, name);
 		return (header != null ? header.getValue() : null);
@@ -495,6 +506,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 		setCommitted(true);
 	}
 
+	@Nullable
 	public String getRedirectedUrl() {
 		return getHeader(HttpHeaders.LOCATION);
 	}
@@ -625,6 +637,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 		return this.status;
 	}
 
+	@Nullable
 	public String getErrorMessage() {
 		return this.errorMessage;
 	}
@@ -634,21 +647,23 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	// Methods for MockRequestDispatcher
 	//---------------------------------------------------------------------
 
-	public void setForwardedUrl(String forwardedUrl) {
+	public void setForwardedUrl(@Nullable String forwardedUrl) {
 		this.forwardedUrl = forwardedUrl;
 	}
 
+	@Nullable
 	public String getForwardedUrl() {
 		return this.forwardedUrl;
 	}
 
-	public void setIncludedUrl(String includedUrl) {
+	public void setIncludedUrl(@Nullable String includedUrl) {
 		this.includedUrls.clear();
 		if (includedUrl != null) {
 			this.includedUrls.add(includedUrl);
 		}
 	}
 
+	@Nullable
 	public String getIncludedUrl() {
 		int count = this.includedUrls.size();
 		Assert.state(count <= 1,
@@ -702,7 +717,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 		}
 
 		@Override
-		public void write(char buf[], int off, int len) {
+		public void write(char[] buf, int off, int len) {
 			super.write(buf, off, len);
 			super.flush();
 			setCommittedIfBufferSizeExceeded();
@@ -727,6 +742,13 @@ public class MockHttpServletResponse implements HttpServletResponse {
 			super.flush();
 			setCommitted(true);
 		}
+
+		@Override
+		public void close() {
+			super.flush();
+			super.close();
+			setCommitted(true);
+		}
 	}
 
 }