Improve no content handling in MockHttpServletRequest

Issue: SPR-11764

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

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -104,6 +104,9 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	private static final String CHARSET_PREFIX = "charset=";
 
+	private static final ServletInputStream EMPTY_SERVLET_INPUT_STREAM =
+			new DelegatingServletInputStream(new ByteArrayInputStream(new byte[0]));
+
 
 	private boolean active = true;
 
@@ -375,7 +378,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 			return new DelegatingServletInputStream(new ByteArrayInputStream(this.content));
 		}
 		else {
-			return null;
+			return EMPTY_SERVLET_INPUT_STREAM;
 		}
 	}
 

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

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
 
 package org.springframework.mock.web;
 
+import java.io.IOException;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -26,6 +28,7 @@ import java.util.Locale;
 import java.util.Map;
 
 import org.junit.Test;
+import org.springframework.util.StreamUtils;
 
 import static org.junit.Assert.*;
 
@@ -42,6 +45,22 @@ public class MockHttpServletRequestTests {
 	private MockHttpServletRequest request = new MockHttpServletRequest();
 
 
+	@Test
+	public void content() throws IOException {
+		byte[] bytes = "body".getBytes(Charset.defaultCharset());
+		request.setContent(bytes);
+		assertEquals(bytes.length, request.getContentLength());
+		assertNotNull(request.getInputStream());
+		assertEquals("body", StreamUtils.copyToString(request.getInputStream(), Charset.defaultCharset()));
+	}
+
+	@Test
+	public void noContent() throws IOException {
+		assertEquals(-1, request.getContentLength());
+		assertNotNull(request.getInputStream());
+		assertEquals(-1, request.getInputStream().read());
+	}
+
 	@Test
 	public void setContentType() {
 		String contentType = "test/plain";

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

@@ -107,6 +107,9 @@ public class MockHttpServletRequest implements HttpServletRequest {
 
 	private static final String CHARSET_PREFIX = "charset=";
 
+	private static final ServletInputStream EMPTY_SERVLET_INPUT_STREAM =
+			new DelegatingServletInputStream(new ByteArrayInputStream(new byte[0]));
+
 
 	private boolean active = true;
 
@@ -378,7 +381,7 @@ public class MockHttpServletRequest implements HttpServletRequest {
 			return new DelegatingServletInputStream(new ByteArrayInputStream(this.content));
 		}
 		else {
-			return null;
+			return EMPTY_SERVLET_INPUT_STREAM;
 		}
 	}