Add Jackson 2 HttpMessageConverter and View

Jackson 2 uses completely new package names and new maven artifact ids.
This change adds Jackson 2 as an optional dependency and also provides
MappingJackson2HttpMessageConverter and MappingJackson2JsonView for use
with the new version.

The MVC namespace and the MVC Java config detect and use
MappingJackson2HttpMessageConverter if Jackson 2 is present.
Otherwise if Jackson 1.x is present,
then MappingJacksonHttpMessageConverter is used.

Issue: SPR-9302

build.gradle

@@ -327,6 +327,7 @@ project('spring-web') {
         compile("commons-httpclient:commons-httpclient:3.1", optional)
         compile("org.apache.httpcomponents:httpclient:4.1.1", optional)
         compile("org.codehaus.jackson:jackson-mapper-asl:1.4.2", optional)
+        compile("com.fasterxml.jackson.core:jackson-databind:2.0.1", optional)
         compile("taglibs:standard:1.1.2", optional)
         compile("org.mortbay.jetty:jetty:6.1.9") { dep ->
             optional dep

spring-web/src/main/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverter.java

@@ -0,0 +1,188 @@
+/*
+ * Copyright 2002-2012 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.http.converter.json;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.List;
+
+import org.springframework.http.HttpInputMessage;
+import org.springframework.http.HttpOutputMessage;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.AbstractHttpMessageConverter;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.http.converter.HttpMessageNotWritableException;
+import org.springframework.util.Assert;
+
+import com.fasterxml.jackson.core.JsonEncoding;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * Implementation of {@link org.springframework.http.converter.HttpMessageConverter HttpMessageConverter}
+ * that can read and write JSON using <a href="http://jackson.codehaus.org/">Jackson 2's</a> {@link ObjectMapper}.
+ *
+ * <p>This converter can be used to bind to typed beans, or untyped {@link java.util.HashMap HashMap} instances.
+ *
+ * <p>By default, this converter supports {@code application/json}. This can be overridden by setting the
+ * {@link #setSupportedMediaTypes(List) supportedMediaTypes} property.
+ *
+ * @author Arjen Poutsma
+ * @author Keith Donald
+ * @since 3.2
+ * @see org.springframework.web.servlet.view.json.MappingJackson2JsonView
+ */
+public class MappingJackson2HttpMessageConverter extends AbstractHttpMessageConverter<Object> {
+
+	public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
+
+
+	private ObjectMapper objectMapper = new ObjectMapper();
+
+	private boolean prefixJson = false;
+
+
+	/**
+	 * Construct a new {@code BindingJacksonHttpMessageConverter}.
+	 */
+	public MappingJackson2HttpMessageConverter() {
+		super(new MediaType("application", "json", DEFAULT_CHARSET));
+	}
+
+	/**
+	 * Set the {@code ObjectMapper} for this view. If not set, a default
+	 * {@link ObjectMapper#ObjectMapper() ObjectMapper} is used.
+	 * <p>Setting a custom-configured {@code ObjectMapper} is one way to take further control of the JSON
+	 * serialization process. For example, an extended {@link org.codehaus.jackson.map.SerializerFactory}
+	 * can be configured that provides custom serializers for specific types. The other option for refining
+	 * the serialization process is to use Jackson's provided annotations on the types to be serialized,
+	 * in which case a custom-configured ObjectMapper is unnecessary.
+	 */
+	public void setObjectMapper(ObjectMapper objectMapper) {
+		Assert.notNull(objectMapper, "ObjectMapper must not be null");
+		this.objectMapper = objectMapper;
+	}
+
+	/**
+	 * Return the underlying {@code ObjectMapper} for this view.
+	 */
+	public ObjectMapper getObjectMapper() {
+		return this.objectMapper;
+	}
+
+	/**
+	 * Indicate whether the JSON output by this view should be prefixed with "{} &&". Default is false.
+	 * <p>Prefixing the JSON string in this manner is used to help prevent JSON Hijacking.
+	 * The prefix renders the string syntactically invalid as a script so that it cannot be hijacked.
+	 * This prefix does not affect the evaluation of JSON, but if JSON validation is performed on the
+	 * string, the prefix would need to be ignored.
+	 */
+	public void setPrefixJson(boolean prefixJson) {
+		this.prefixJson = prefixJson;
+	}
+
+
+	@Override
+	public boolean canRead(Class<?> clazz, MediaType mediaType) {
+		JavaType javaType = getJavaType(clazz);
+		return (this.objectMapper.canDeserialize(javaType) && canRead(mediaType));
+	}
+
+	@Override
+	public boolean canWrite(Class<?> clazz, MediaType mediaType) {
+		return (this.objectMapper.canSerialize(clazz) && canWrite(mediaType));
+	}
+
+	@Override
+	protected boolean supports(Class<?> clazz) {
+		// should not be called, since we override canRead/Write instead
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage)
+			throws IOException, HttpMessageNotReadableException {
+
+		JavaType javaType = getJavaType(clazz);
+		try {
+			return this.objectMapper.readValue(inputMessage.getBody(), javaType);
+		}
+		catch (JsonProcessingException ex) {
+			throw new HttpMessageNotReadableException("Could not read JSON: " + ex.getMessage(), ex);
+		}
+	}
+
+	@Override
+	protected void writeInternal(Object object, HttpOutputMessage outputMessage)
+			throws IOException, HttpMessageNotWritableException {
+
+		JsonEncoding encoding = getJsonEncoding(outputMessage.getHeaders().getContentType());
+		JsonGenerator jsonGenerator =
+				this.objectMapper.getJsonFactory().createJsonGenerator(outputMessage.getBody(), encoding);
+		try {
+			if (this.prefixJson) {
+				jsonGenerator.writeRaw("{} && ");
+			}
+			this.objectMapper.writeValue(jsonGenerator, object);
+		}
+		catch (JsonProcessingException ex) {
+			throw new HttpMessageNotWritableException("Could not write JSON: " + ex.getMessage(), ex);
+		}
+	}
+
+
+	/**
+	 * Return the Jackson {@link JavaType} for the specified class.
+	 * <p>The default implementation returns {@link ObjectMapper#constructType(java.lang.reflect.Type)},
+	 * but this can be overridden in subclasses, to allow for custom generic collection handling.
+	 * For instance:
+	 * <pre class="code">
+	 * protected JavaType getJavaType(Class&lt;?&gt; clazz) {
+	 *   if (List.class.isAssignableFrom(clazz)) {
+	 *     return objectMapper.getTypeFactory().constructCollectionType(ArrayList.class, MyBean.class);
+	 *   } else {
+	 *     return super.getJavaType(clazz);
+	 *   }
+	 * }
+	 * </pre>
+	 * @param clazz the class to return the java type for
+	 * @return the java type
+	 */
+	protected JavaType getJavaType(Class<?> clazz) {
+		return objectMapper.constructType(clazz);
+	}
+
+	/**
+	 * Determine the JSON encoding to use for the given content type.
+	 * @param contentType the media type as requested by the caller
+	 * @return the JSON encoding to use (never <code>null</code>)
+	 */
+	protected JsonEncoding getJsonEncoding(MediaType contentType) {
+		if (contentType != null && contentType.getCharSet() != null) {
+			Charset charset = contentType.getCharSet();
+			for (JsonEncoding encoding : JsonEncoding.values()) {
+				if (charset.name().equals(encoding.getJavaName())) {
+					return encoding;
+				}
+			}
+		}
+		return JsonEncoding.UTF8;
+	}
+
+}

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -40,6 +40,7 @@ import org.springframework.http.converter.ResourceHttpMessageConverter;
 import org.springframework.http.converter.StringHttpMessageConverter;
 import org.springframework.http.converter.feed.AtomFeedHttpMessageConverter;
 import org.springframework.http.converter.feed.RssChannelHttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.http.converter.json.MappingJacksonHttpMessageConverter;
 import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
 import org.springframework.http.converter.xml.SourceHttpMessageConverter;
@@ -118,6 +119,10 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 	private static final boolean jaxb2Present =
 			ClassUtils.isPresent("javax.xml.bind.Binder", RestTemplate.class.getClassLoader());
 
+	private static final boolean jackson2Present =
+			ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", RestTemplate.class.getClassLoader()) &&
+					ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", RestTemplate.class.getClassLoader());
+
 	private static final boolean jacksonPresent =
 			ClassUtils.isPresent("org.codehaus.jackson.map.ObjectMapper", RestTemplate.class.getClassLoader()) &&
 					ClassUtils.isPresent("org.codehaus.jackson.JsonGenerator", RestTemplate.class.getClassLoader());
@@ -143,7 +148,10 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 		if (jaxb2Present) {
 			this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
 		}
-		if (jacksonPresent) {
+		if (jackson2Present) {
+			this.messageConverters.add(new MappingJackson2HttpMessageConverter());
+		}
+		else if (jacksonPresent) {
 			this.messageConverters.add(new MappingJacksonHttpMessageConverter());
 		}
 		if (romePresent) {

spring-web/src/test/java/org/springframework/http/converter/json/MappingJacksonHttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -23,29 +23,47 @@ import static org.junit.Assert.assertTrue;
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import org.codehaus.jackson.map.type.TypeFactory;
 import org.codehaus.jackson.type.JavaType;
-import org.junit.Before;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
 import org.springframework.http.MediaType;
 import org.springframework.http.MockHttpInputMessage;
 import org.springframework.http.MockHttpOutputMessage;
+import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 
 /**
+ * Jackson conversion tests parameterized with Jackson and Jackson 2 converters.
+ *
  * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
  */
+@RunWith(Parameterized.class)
 public class MappingJacksonHttpMessageConverterTests {
 
-	private MappingJacksonHttpMessageConverter converter;
+	private HttpMessageConverter<Object> converter;
 
-	@Before
+	@Parameters
-	public void setUp() {
+	public static Collection<Object[]> handlerTypes() {
-		converter = new MappingJacksonHttpMessageConverter();
+		Object[][] array = new Object[2][1];
+
+		array[0] = new Object[] { new MappingJackson2HttpMessageConverter()};
+		array[1] = new Object[] { new MappingJacksonHttpMessageConverter()};
+
+		return Arrays.asList(array);
+	}
+
+	public MappingJacksonHttpMessageConverterTests(HttpMessageConverter<Object> converter) {
+		this.converter = converter;
 	}
 
 	@Test

spring-webmvc/src/main/java/org/springframework/web/servlet/config/AnnotationDrivenBeanDefinitionParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -35,6 +35,7 @@ import org.springframework.http.converter.ResourceHttpMessageConverter;
 import org.springframework.http.converter.StringHttpMessageConverter;
 import org.springframework.http.converter.feed.AtomFeedHttpMessageConverter;
 import org.springframework.http.converter.feed.RssChannelHttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.http.converter.json.MappingJacksonHttpMessageConverter;
 import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
 import org.springframework.http.converter.xml.SourceHttpMessageConverter;
@@ -125,6 +126,10 @@ class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser {
 	private static final boolean jaxb2Present =
 			ClassUtils.isPresent("javax.xml.bind.Binder", AnnotationDrivenBeanDefinitionParser.class.getClassLoader());
 
+	private static final boolean jackson2Present =
+			ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", AnnotationDrivenBeanDefinitionParser.class.getClassLoader()) &&
+					ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", AnnotationDrivenBeanDefinitionParser.class.getClassLoader());
+
 	private static final boolean jacksonPresent =
 			ClassUtils.isPresent("org.codehaus.jackson.map.ObjectMapper", AnnotationDrivenBeanDefinitionParser.class.getClassLoader()) &&
 					ClassUtils.isPresent("org.codehaus.jackson.JsonGenerator", AnnotationDrivenBeanDefinitionParser.class.getClassLoader());
@@ -309,7 +314,10 @@ class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser {
 				messageConverters
 						.add(createConverterBeanDefinition(Jaxb2RootElementHttpMessageConverter.class, source));
 			}
-			if (jacksonPresent) {
+			if (jackson2Present) {
+				messageConverters.add(createConverterBeanDefinition(MappingJackson2HttpMessageConverter.class, source));
+			}
+			else if (jacksonPresent) {
 				messageConverters.add(createConverterBeanDefinition(MappingJacksonHttpMessageConverter.class, source));
 			}
 			if (romePresent) {

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupport.java

@@ -41,6 +41,7 @@ import org.springframework.http.converter.ResourceHttpMessageConverter;
 import org.springframework.http.converter.StringHttpMessageConverter;
 import org.springframework.http.converter.feed.AtomFeedHttpMessageConverter;
 import org.springframework.http.converter.feed.RssChannelHttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.http.converter.json.MappingJacksonHttpMessageConverter;
 import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
 import org.springframework.http.converter.xml.SourceHttpMessageConverter;
@@ -374,7 +375,10 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		if (ClassUtils.isPresent("javax.xml.bind.Binder", classLoader)) {
 			messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
 		}
-		if (ClassUtils.isPresent("org.codehaus.jackson.map.ObjectMapper", classLoader)) {
+		if (ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader)) {
+			messageConverters.add(new MappingJackson2HttpMessageConverter());
+		}
+		else if (ClassUtils.isPresent("org.codehaus.jackson.map.ObjectMapper", classLoader)) {
 			messageConverters.add(new MappingJacksonHttpMessageConverter());
 		}
 		if (ClassUtils.isPresent("com.sun.syndication.feed.WireFeed", classLoader)) {

spring-webmvc/src/main/java/org/springframework/web/servlet/view/json/MappingJackson2JsonView.java

@@ -0,0 +1,220 @@
+/*
+ * Copyright 2002-2012 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.view.json;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import com.fasterxml.jackson.core.JsonEncoding;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
+import org.springframework.validation.BindingResult;
+import org.springframework.web.servlet.View;
+import org.springframework.web.servlet.view.AbstractView;
+
+/**
+ * Spring MVC {@link View} that renders JSON content by serializing the model for the current request
+ * using <a href="http://jackson.codehaus.org/">Jackson 2's</a> {@link ObjectMapper}.
+ *
+ * <p>By default, the entire contents of the model map (with the exception of framework-specific classes)
+ * will be encoded as JSON. If the model contains only one key, you can have it extracted encoded as JSON
+ * alone via  {@link #setExtractValueFromSingleKeyModel}.
+ *
+ * @author Jeremy Grelle
+ * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
+ * @since 3.2
+ * @see org.springframework.http.converter.json.MappingJackson2HttpMessageConverter
+ */
+public class MappingJackson2JsonView extends AbstractView {
+
+	/**
+	 * Default content type. Overridable as bean property.
+	 */
+	public static final String DEFAULT_CONTENT_TYPE = "application/json";
+
+
+	private ObjectMapper objectMapper = new ObjectMapper();
+
+	private JsonEncoding encoding = JsonEncoding.UTF8;
+
+	private boolean prefixJson = false;
+
+	private Set<String> modelKeys;
+
+	private boolean extractValueFromSingleKeyModel = false;
+
+	private boolean disableCaching = true;
+
+
+	/**
+	 * Construct a new {@code JacksonJsonView}, setting the content type to {@code application/json}.
+	 */
+	public MappingJackson2JsonView() {
+		setContentType(DEFAULT_CONTENT_TYPE);
+		setExposePathVariables(false);
+	}
+
+
+	/**
+	 * Sets the {@code ObjectMapper} for this view.
+	 * If not set, a default {@link ObjectMapper#ObjectMapper() ObjectMapper} is used.
+	 * <p>Setting a custom-configured {@code ObjectMapper} is one way to take further control
+	 * of the JSON serialization process. For example, an extended {@code SerializerFactory}
+	 * can be configured that provides custom serializers for specific types. The other option
+	 * for refining the serialization process is to use Jackson's provided annotations on the
+	 * types to be serialized, in which case a custom-configured ObjectMapper is unnecessary.
+	 */
+	public void setObjectMapper(ObjectMapper objectMapper) {
+		Assert.notNull(objectMapper, "'objectMapper' must not be null");
+		this.objectMapper = objectMapper;
+	}
+
+	/**
+	 * Set the {@code JsonEncoding} for this converter.
+	 * By default, {@linkplain JsonEncoding#UTF8 UTF-8} is used.
+	 */
+	public void setEncoding(JsonEncoding encoding) {
+		Assert.notNull(encoding, "'encoding' must not be null");
+		this.encoding = encoding;
+	}
+
+	/**
+	 * Indicates whether the JSON output by this view should be prefixed with <tt>"{} && "</tt>.
+	 * Default is false.
+	 * <p>Prefixing the JSON string in this manner is used to help prevent JSON Hijacking.
+	 * The prefix renders the string syntactically invalid as a script so that it cannot be hijacked.
+	 * This prefix does not affect the evaluation of JSON, but if JSON validation is performed
+	 * on the string, the prefix would need to be ignored.
+	 */
+	public void setPrefixJson(boolean prefixJson) {
+		this.prefixJson = prefixJson;
+	}
+
+	/**
+	 * Set the attribute in the model that should be rendered by this view.
+	 * When set, all other model attributes will be ignored.
+	 */
+	public void setModelKey(String modelKey) {
+		this.modelKeys = Collections.singleton(modelKey);
+	}
+
+	/**
+	 * Set the attributes in the model that should be rendered by this view.
+	 * When set, all other model attributes will be ignored.
+	 */
+	public void setModelKeys(Set<String> modelKeys) {
+		this.modelKeys = modelKeys;
+	}
+
+	/**
+	 * Return the attributes in the model that should be rendered by this view.
+	 */
+	public Set<String> getModelKeys() {
+		return this.modelKeys;
+	}
+
+	/**
+	 * Set the attributes in the model that should be rendered by this view.
+	 * When set, all other model attributes will be ignored.
+	 * @deprecated use {@link #setModelKeys(Set)} instead
+	 */
+	@Deprecated
+	public void setRenderedAttributes(Set<String> renderedAttributes) {
+		this.modelKeys = renderedAttributes;
+	}
+
+	/**
+	 * Return the attributes in the model that should be rendered by this view.
+	 * @deprecated use {@link #getModelKeys()} instead
+	 */
+	@Deprecated
+	public Set<String> getRenderedAttributes() {
+		return this.modelKeys;
+	}
+
+	/**
+	 * Set whether to serialize models containing a single attribute as a map or whether to
+	 * extract the single value from the model and serialize it directly.
+	 * <p>The effect of setting this flag is similar to using {@code MappingJacksonHttpMessageConverter}
+	 * with an {@code @ResponseBody} request-handling method.
+	 * <p>Default is {@code false}.
+	 */
+	public void setExtractValueFromSingleKeyModel(boolean extractValueFromSingleKeyModel) {
+		this.extractValueFromSingleKeyModel = extractValueFromSingleKeyModel;
+	}
+
+	/**
+	 * Disables caching of the generated JSON.
+	 * <p>Default is {@code true}, which will prevent the client from caching the generated JSON.
+	 */
+	public void setDisableCaching(boolean disableCaching) {
+		this.disableCaching = disableCaching;
+	}
+
+
+	@Override
+	protected void prepareResponse(HttpServletRequest request, HttpServletResponse response) {
+		response.setContentType(getContentType());
+		response.setCharacterEncoding(this.encoding.getJavaName());
+		if (this.disableCaching) {
+			response.addHeader("Pragma", "no-cache");
+			response.addHeader("Cache-Control", "no-cache, no-store, max-age=0");
+			response.addDateHeader("Expires", 1L);
+		}
+	}
+
+	@Override
+	protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request,
+			HttpServletResponse response) throws Exception {
+
+		Object value = filterModel(model);
+		JsonGenerator generator =
+				this.objectMapper.getJsonFactory().createJsonGenerator(response.getOutputStream(), this.encoding);
+		if (this.prefixJson) {
+			generator.writeRaw("{} && ");
+		}
+		this.objectMapper.writeValue(generator, value);
+	}
+
+	/**
+	 * Filters out undesired attributes from the given model.
+	 * The return value can be either another {@link Map} or a single value object.
+	 * <p>The default implementation removes {@link BindingResult} instances and entries
+	 * not included in the {@link #setRenderedAttributes renderedAttributes} property.
+	 * @param model the model, as passed on to {@link #renderMergedOutputModel}
+	 * @return the object to be rendered
+	 */
+	protected Object filterModel(Map<String, Object> model) {
+		Map<String, Object> result = new HashMap<String, Object>(model.size());
+		Set<String> renderedAttributes = (!CollectionUtils.isEmpty(this.modelKeys) ? this.modelKeys : model.keySet());
+		for (Map.Entry<String, Object> entry : model.entrySet()) {
+			if (!(entry.getValue() instanceof BindingResult) && renderedAttributes.contains(entry.getKey())) {
+				result.put(entry.getKey(), entry.getValue());
+			}
+		}
+		return (this.extractValueFromSingleKeyModel && result.size() == 1 ? result.values().iterator().next() : result);
+	}
+
+}

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupportTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -35,7 +35,7 @@ import org.springframework.core.io.FileSystemResourceLoader;
 import org.springframework.format.FormatterRegistry;
 import org.springframework.format.support.FormattingConversionService;
 import org.springframework.http.converter.HttpMessageConverter;
-import org.springframework.http.converter.json.MappingJacksonHttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockServletContext;
 import org.springframework.stereotype.Controller;
@@ -262,7 +262,7 @@ public class WebMvcConfigurationSupportTests {
 
 		@Override
 		public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
-			converters.add(new MappingJacksonHttpMessageConverter());
+			converters.add(new MappingJackson2HttpMessageConverter());
 		}
 
 		@Override

spring-webmvc/src/test/java/org/springframework/web/servlet/view/json/MappingJackson2JsonViewTest.java

@@ -0,0 +1,352 @@
+/*
+ * Copyright 2002-2012 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.view.json;
+
+import static org.easymock.EasyMock.createMock;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.ContextFactory;
+import org.mozilla.javascript.ScriptableObject;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.validation.BindingResult;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.BeanProperty;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.fasterxml.jackson.databind.cfg.SerializerFactoryConfig;
+import com.fasterxml.jackson.databind.ser.BasicSerializerFactory;
+import com.fasterxml.jackson.databind.ser.BeanSerializerFactory;
+import com.fasterxml.jackson.databind.ser.SerializerFactory;
+import com.fasterxml.jackson.databind.ser.Serializers;
+
+/**
+ * @author Jeremy Grelle
+ * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
+ */
+public class MappingJackson2JsonViewTest {
+
+	private MappingJackson2JsonView view;
+
+	private MockHttpServletRequest request;
+
+	private MockHttpServletResponse response;
+
+	private Context jsContext;
+
+	private ScriptableObject jsScope;
+
+	@Before
+	public void setUp() {
+		request = new MockHttpServletRequest();
+		response = new MockHttpServletResponse();
+
+		jsContext = ContextFactory.getGlobal().enterContext();
+		jsScope = jsContext.initStandardObjects();
+
+		view = new MappingJackson2JsonView();
+	}
+
+	@Test
+	public void isExposePathVars() {
+		assertEquals("Must not expose path variables", false, view.isExposePathVariables());
+	}
+
+	@Test
+	public void renderSimpleMap() throws Exception {
+
+		Map<String, Object> model = new HashMap<String, Object>();
+		model.put("bindingResult", createMock("binding_result", BindingResult.class));
+		model.put("foo", "bar");
+
+		view.render(model, request, response);
+
+		assertEquals("no-cache", response.getHeader("Pragma"));
+		assertEquals("no-cache, no-store, max-age=0", response.getHeader("Cache-Control"));
+		assertNotNull(response.getHeader("Expires"));
+
+		assertEquals(MappingJacksonJsonView.DEFAULT_CONTENT_TYPE, response.getContentType());
+
+		String jsonResult = response.getContentAsString();
+		assertTrue(jsonResult.length() > 0);
+
+		validateResult();
+	}
+
+	@Test
+	public void renderCaching() throws Exception {
+		view.setDisableCaching(false);
+
+		Map<String, Object> model = new HashMap<String, Object>();
+		model.put("bindingResult", createMock("binding_result", BindingResult.class));
+		model.put("foo", "bar");
+
+		view.render(model, request, response);
+
+		assertNull(response.getHeader("Pragma"));
+		assertNull(response.getHeader("Cache-Control"));
+		assertNull(response.getHeader("Expires"));
+	}
+
+	@Test
+	public void renderSimpleMapPrefixed() throws Exception {
+		view.setPrefixJson(true);
+		renderSimpleMap();
+	}
+
+	@Test
+	public void renderSimpleBean() throws Exception {
+
+		Object bean = new TestBeanSimple();
+		Map<String, Object> model = new HashMap<String, Object>();
+		model.put("bindingResult", createMock("binding_result", BindingResult.class));
+		model.put("foo", bean);
+
+		view.render(model, request, response);
+
+		assertTrue(response.getContentAsString().length() > 0);
+
+		validateResult();
+	}
+
+	@Test
+	public void renderSimpleBeanPrefixed() throws Exception {
+
+		view.setPrefixJson(true);
+		renderSimpleBean();
+	}
+
+	@Test
+	public void renderWithCustomSerializerLocatedByAnnotation() throws Exception {
+
+		Object bean = new TestBeanSimpleAnnotated();
+		Map<String, Object> model = new HashMap<String, Object>();
+		model.put("foo", bean);
+
+		view.render(model, request, response);
+
+		assertTrue(response.getContentAsString().length() > 0);
+		assertEquals("{\"foo\":{\"testBeanSimple\":\"custom\"}}", response.getContentAsString());
+
+		validateResult();
+	}
+
+	@Test
+	public void renderWithCustomSerializerLocatedByFactory() throws Exception {
+
+		SerializerFactory factory = new DelegatingSerializerFactory(null);
+		ObjectMapper mapper = new ObjectMapper();
+		mapper.setSerializerFactory(factory);
+		view.setObjectMapper(mapper);
+
+		Object bean = new TestBeanSimple();
+		Map<String, Object> model = new HashMap<String, Object>();
+		model.put("foo", bean);
+		model.put("bar", new TestChildBean());
+
+		view.render(model, request, response);
+
+		String result = response.getContentAsString();
+		assertTrue(result.length() > 0);
+		assertTrue(result.contains("\"foo\":{\"testBeanSimple\":\"custom\"}"));
+
+		validateResult();
+	}
+
+	@Test
+	public void renderOnlyIncludedAttributes() throws Exception {
+
+		Set<String> attrs = new HashSet<String>();
+		attrs.add("foo");
+		attrs.add("baz");
+		attrs.add("nil");
+
+		view.setModelKeys(attrs);
+		Map<String, Object> model = new HashMap<String, Object>();
+		model.put("foo", "foo");
+		model.put("bar", "bar");
+		model.put("baz", "baz");
+
+		view.render(model, request, response);
+
+		String result = response.getContentAsString();
+		assertTrue(result.length() > 0);
+		assertTrue(result.contains("\"foo\":\"foo\""));
+		assertTrue(result.contains("\"baz\":\"baz\""));
+
+		validateResult();
+	}
+
+	@Test
+	public void filterSingleKeyModel() throws Exception {
+		view.setExtractValueFromSingleKeyModel(true);
+
+		Map<String, Object> model = new HashMap<String, Object>();
+		TestBeanSimple bean = new TestBeanSimple();
+		model.put("foo", bean);
+
+		Object actual = view.filterModel(model);
+
+		assertSame(bean, actual);
+	}
+
+	@SuppressWarnings("rawtypes")
+	@Test
+	public void filterTwoKeyModel() throws Exception {
+		view.setExtractValueFromSingleKeyModel(true);
+
+		Map<String, Object> model = new HashMap<String, Object>();
+		TestBeanSimple bean1 = new TestBeanSimple();
+		TestBeanSimple bean2 = new TestBeanSimple();
+		model.put("foo1", bean1);
+		model.put("foo2", bean2);
+
+		Object actual = view.filterModel(model);
+
+		assertTrue(actual instanceof Map);
+		assertSame(bean1, ((Map) actual).get("foo1"));
+		assertSame(bean2, ((Map) actual).get("foo2"));
+	}
+
+	private void validateResult() throws Exception {
+		Object jsResult =
+				jsContext.evaluateString(jsScope, "(" + response.getContentAsString() + ")", "JSON Stream", 1, null);
+		assertNotNull("Json Result did not eval as valid JavaScript", jsResult);
+	}
+
+
+	public static class TestBeanSimple {
+
+		private String value = "foo";
+
+		private boolean test = false;
+
+		private long number = 42;
+
+		private TestChildBean child = new TestChildBean();
+
+		public String getValue() {
+			return value;
+		}
+
+		public boolean getTest() {
+			return test;
+		}
+
+		public long getNumber() {
+			return number;
+		}
+
+		public Date getNow() {
+			return new Date();
+		}
+
+		public TestChildBean getChild() {
+			return child;
+		}
+	}
+
+	@JsonSerialize(using=TestBeanSimpleSerializer.class)
+	public static class TestBeanSimpleAnnotated extends TestBeanSimple {
+
+	}
+
+	public static class TestChildBean {
+
+		private String value = "bar";
+
+		private String baz = null;
+
+		private TestBeanSimple parent = null;
+
+		public String getValue() {
+			return value;
+		}
+
+		public String getBaz() {
+			return baz;
+		}
+
+		public TestBeanSimple getParent() {
+			return parent;
+		}
+
+		public void setParent(TestBeanSimple parent) {
+			this.parent = parent;
+		}
+	}
+
+	public static class TestBeanSimpleSerializer extends JsonSerializer<Object> {
+
+		@Override
+		public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
+			jgen.writeStartObject();
+			jgen.writeFieldName("testBeanSimple");
+			jgen.writeString("custom");
+			jgen.writeEndObject();
+		}
+	}
+
+	public static class DelegatingSerializerFactory extends BasicSerializerFactory {
+
+		private SerializerFactory beanSerializer = BeanSerializerFactory.instance;
+
+		protected DelegatingSerializerFactory(SerializerFactoryConfig config) {
+			super(config);
+		}
+
+		@Override
+	    public JsonSerializer<Object> createSerializer(SerializerProvider prov, JavaType type, BeanProperty property) throws JsonMappingException {
+			if (type.getRawClass() == TestBeanSimple.class) {
+				return new TestBeanSimpleSerializer();
+			}
+			else {
+				return beanSerializer.createSerializer(prov, type, property);
+			}
+		}
+
+		@Override
+		public SerializerFactory withConfig(SerializerFactoryConfig config) {
+			return null;
+		}
+
+		@Override
+		protected Iterable<Serializers> customSerializers() {
+			return null;
+		}
+	}
+}

spring-webmvc/src/test/java/org/springframework/web/servlet/view/json/MappingJacksonJsonViewTest.java

@@ -38,6 +38,7 @@ import org.codehaus.jackson.map.SerializerFactory;
 import org.codehaus.jackson.map.SerializerProvider;
 import org.codehaus.jackson.map.annotate.JsonSerialize;
 import org.codehaus.jackson.map.ser.BeanSerializerFactory;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.mozilla.javascript.Context;

src/dist/changelog.txt

@@ -13,6 +13,7 @@ Changes in version 3.2 M1
 * fix case-sensitivity issue with some containers on access to 'Content-Disposition' header
 * add Servlet 3.0 based async support
 * fix issue with encoded params in UriComponentsBuilder
+* add Jackson 2 HttpMessageConverter and View types
 
 Changes in version 3.1.1 (2012-02-16)
 -------------------------------------

src/reference/docbook/mvc.xml

@@ -2892,7 +2892,7 @@ public String upload(...) {
   </property>
   <property name="defaultViews">
     <list>
-      <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" />
+      <bean class="org.springframework.web.servlet.view.json.MappingJackson2JsonView" />
     </list>
   </property>
 </bean>
@@ -2924,7 +2924,7 @@ public String upload(...) {
       the <classname>SampleContentAtomView</classname> if the view name
       returned is <classname>content</classname>. If the request is made with
       the file extension <literal>.json</literal>, the
-      <classname>MappingJacksonJsonView</classname> instance from the
+      <classname>MappingJackson2JsonView</classname>instance from the
       <literal>DefaultViews</literal> list will be selected regardless of the
       view name. Alternatively, client requests can be made without a file
       extension but with the <literal>Accept</literal> header set to the
@@ -3588,7 +3588,7 @@ public String onSubmit(<emphasis role="bold">@RequestPart("meta-data") MetaData
       However, the <literal>@RequestPart("meta-data") MetaData</literal>
       method argument in this case is read as JSON content based on its
       <literal>'Content-Type'</literal> header and converted with the help of
-      the <classname>MappingJacksonHttpMessageConverter</classname>.</para>
+      the <classname>MappingJackson2HttpMessageConverter</classname>.</para>
     </section>
   </section>
 
@@ -4256,9 +4256,10 @@ public class WebConfig {
                 </listitem>
 
                 <listitem>
-                  <para><classname>MappingJacksonHttpMessageConverter</classname>
+                  <para><classname>MappingJackson2HttpMessageConverter</classname>
-                  converts to/from JSON — added if Jackson is present on the
+                  (or <classname>MappingJacksonHttpMessageConverter</classname>)
-                  classpath.</para>
+                  converts to/from JSON — added if Jackson 2 (or Jackson) is present
+                  on the classpath.</para>
                 </listitem>
 
                 <listitem>

src/reference/docbook/remoting.xml

@@ -1363,7 +1363,7 @@ if (HttpStatus.SC_CREATED == post.getStatusCode()) {
       these defaults using the <methodname>messageConverters()</methodname> bean
       property as would be required if using the
       <classname>MarshallingHttpMessageConverter</classname> or 
-      <classname>MappingJacksonHttpMessageConverter</classname>.</para>
+      <classname>MappingJackson2HttpMessageConverter</classname>.</para>
 
       <para>Each method takes URI template arguments in two forms, either as a
       <literal>String</literal> variable length argument or a
@@ -1608,7 +1608,7 @@ String body = response.getBody();</programlisting>
       </section>
       
       <section id="rest-mapping-json-converter">
-        <title>MappingJacksonHttpMessageConverter</title>
+        <title>MappingJackson2HttpMessageConverter (or MappingJacksonHttpMessageConverter with Jackson 1.x)</title>
         
         <para>An <interfacename>HttpMessageConverter</interfacename> 
         implementation that can read and write JSON using Jackson's 

src/reference/docbook/view.xml

@@ -2626,7 +2626,9 @@ simpleReport.reportDataKey=myBeanData</programlisting>
   <section id="view-json-mapping">
   	<title>JSON Mapping View</title>
   	
-  	<para>The <classname>MappingJacksonJsonView</classname> uses the Jackson 
+        <para>The <classname>MappingJackson2JsonView</classname>
+        (or <classname>MappingJacksonJsonView</classname> depending on the
+        the Jackson version you have) uses the Jackson
   	library's <classname>ObjectMapper</classname> to render the response content 
   	as JSON. By default, the entire contents of the model map (with the exception 
   	of framework-specific classes) will be encoded as JSON. For cases where the