MockHttpServletRequest returns a single InputStream or Reader

Issue: SPR-16505
Issue: SPR-16499

spring-test/src/main/java/org/springframework/mock/web/MockHttpServletRequest.java

@@ -178,6 +178,12 @@ public class MockHttpServletRequest implements HttpServletRequest {
 	@Nullable
 	private String contentType;
 
+	@Nullable
+	private ServletInputStream inputStream;
+
+	@Nullable
+	private BufferedReader reader;
+
 	private final Map<String, String[]> parameters = new LinkedHashMap<>(16);
 
 	private String protocol = DEFAULT_PROTOCOL;
@@ -492,12 +498,18 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	@Override
 	public ServletInputStream getInputStream() {
-		if (this.content != null) {
-			return new DelegatingServletInputStream(new ByteArrayInputStream(this.content));
+		if (this.inputStream != null) {
+			return this.inputStream;
 		}
-		else {
-			return EMPTY_SERVLET_INPUT_STREAM;
+		else if (this.reader != null) {
+			throw new IllegalStateException(
+					"Cannot call getInputStream() after getReader() has already been called for the current request")			;
 		}
+
+		this.inputStream = (this.content != null ?
+				new DelegatingServletInputStream(new ByteArrayInputStream(this.content)) :
+				EMPTY_SERVLET_INPUT_STREAM);
+		return this.inputStream;
 	}
 
 	/**
@@ -695,16 +707,25 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	@Override
 	public BufferedReader getReader() throws UnsupportedEncodingException {
+		if (this.reader != null) {
+			return this.reader;
+		}
+		else if (this.inputStream != null) {
+			throw new IllegalStateException(
+					"Cannot call getReader() after getInputStream() has already been called for the current request")			;
+		}
+
 		if (this.content != null) {
 			InputStream sourceStream = new ByteArrayInputStream(this.content);
 			Reader sourceReader = (this.characterEncoding != null) ?
 					new InputStreamReader(sourceStream, this.characterEncoding) :
 					new InputStreamReader(sourceStream);
-			return new BufferedReader(sourceReader);
+			this.reader = new BufferedReader(sourceReader);
 		}
 		else {
-			return EMPTY_BUFFERED_READER;
+			this.reader = EMPTY_BUFFERED_READER;
 		}
+		return this.reader;
 	}
 
 	public void setRemoteAddr(String remoteAddr) {

spring-test/src/test/java/org/springframework/mock/web/MockHttpServletRequestTests.java

@@ -47,6 +47,7 @@ import static org.junit.Assert.*;
  * @author Sam Brannen
  * @author Brian Clozel
  * @author Jakub Narloch
+ * @author Av Pinzur
  */
 public class MockHttpServletRequestTests {
 
@@ -112,6 +113,38 @@ public class MockHttpServletRequestTests {
 		assertNull(request.getContentAsByteArray());
 	}
 
+	@Test  // SPR-16505
+	public void getReaderTwice() throws IOException {
+		byte[] bytes = "body".getBytes(Charset.defaultCharset());
+		request.setContent(bytes);
+		assertSame(request.getReader(), request.getReader());
+	}
+
+	@Test  // SPR-16505
+	public void getInputStreamTwice() throws IOException {
+		byte[] bytes = "body".getBytes(Charset.defaultCharset());
+		request.setContent(bytes);
+		assertSame(request.getInputStream(), request.getInputStream());
+	}
+
+	@Test  // SPR-16499
+	public void getReaderAfterGettingInputStream() throws IOException {
+		exception.expect(IllegalStateException.class);
+		exception.expectMessage(
+				"Cannot call getReader() after getInputStream() has already been called for the current request");
+		request.getInputStream();
+		request.getReader();
+	}
+
+	@Test  // SPR-16499
+	public void getInputStreamAfterGettingReader() throws IOException {
+		exception.expect(IllegalStateException.class);
+		exception.expectMessage(
+				"Cannot call getInputStream() after getReader() has already been called for the current request");
+		request.getReader();
+		request.getInputStream();
+	}
+
 	@Test
 	public void setContentType() {
 		String contentType = "test/plain";