INT-2448 Add view-expression to Http Inbound

https://jira.springsource.org/browse/INT-2488

Previously the view name could be specified; with this
change, either the view name or a view-epression can be
provided, with the reply message being the root object
of the evaluation context.

INT-2448 Polishing

Remove deprecation from view-name.

Reuse evaluation context.

INT-2448 Polishing

PR Comments

spring-integration-http/src/main/java/org/springframework/integration/http/config/HttpInboundEndpointParser.java

@@ -27,9 +27,12 @@ import org.springframework.beans.factory.support.ManagedMap;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.beans.factory.xml.AbstractSingleBeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.expression.common.LiteralExpression;
 import org.springframework.integration.channel.DirectChannel;
 import org.springframework.integration.config.ExpressionFactoryBean;
 import org.springframework.integration.config.xml.IntegrationNamespaceUtils;
+import org.springframework.integration.http.inbound.HttpRequestHandlingController;
+import org.springframework.integration.http.inbound.HttpRequestHandlingMessagingGateway;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.util.xml.DomUtils;
@@ -39,8 +42,8 @@ import org.w3c.dom.Element;
  * Parser for the 'inbound-channel-adapter' and 'inbound-gateway' elements
  * of the 'http' namespace. The constructor's boolean value specifies whether
  * a reply is to be expected. This value should be 'false' for the
- * 'inbound-channel-adapter' and 'true' for the 'inbound-gateway'.  
- * 
+ * 'inbound-channel-adapter' and 'true' for the 'inbound-gateway'.
+ *
  * @author Mark Fisher
  * @author Oleg Zhurakousky
  * @author Gary Russell
@@ -57,9 +60,9 @@ public class HttpInboundEndpointParser extends AbstractSingleBeanDefinitionParse
 
 	@Override
 	protected String getBeanClassName(Element element) {
-		return element.hasAttribute("view-name")
-				? "org.springframework.integration.http.inbound.HttpRequestHandlingController"
-				: "org.springframework.integration.http.inbound.HttpRequestHandlingMessagingGateway";
+		return element.hasAttribute("view-name") || element.hasAttribute("view-expression")
+				? HttpRequestHandlingController.class.getName()
+				: HttpRequestHandlingMessagingGateway.class.getName();
 	}
 
 	@Override
@@ -96,18 +99,18 @@ public class HttpInboundEndpointParser extends AbstractSingleBeanDefinitionParse
 		}
 		builder.addPropertyReference("requestChannel", inputChannelRef);
 		IntegrationNamespaceUtils.setReferenceIfAttributeDefined(builder, element, "error-channel");
-		
-		
+
+
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "path");
 		String payloadExpression = element.getAttribute("payload-expression");
-		if (StringUtils.hasText(payloadExpression)){
+		if (StringUtils.hasText(payloadExpression)) {
 			RootBeanDefinition expressionDef = new RootBeanDefinition(ExpressionFactoryBean.class);
 			expressionDef.getConstructorArgumentValues().addGenericArgumentValue(payloadExpression);
 			builder.addPropertyValue("payloadExpression", expressionDef);
 		}
-		
+
 		List<Element> headerElements = DomUtils.getChildElementsByTagName(element, "header");
-		
+
 		if (!CollectionUtils.isEmpty(headerElements)) {
 			ManagedMap<String, Object> headerElementsMap = new ManagedMap<String, Object>();
 			for (Element headerElement : headerElements) {
@@ -117,11 +120,11 @@ public class HttpInboundEndpointParser extends AbstractSingleBeanDefinitionParse
 					RootBeanDefinition expressionDef = new RootBeanDefinition(ExpressionFactoryBean.class);
 					expressionDef.getConstructorArgumentValues().addGenericArgumentValue(expression);
 					headerElementsMap.put(name, expressionDef);
-				}			
+				}
 			}
 			builder.addPropertyValue("headerExpressions", headerElementsMap);
 		}
-		
+
 		if (this.expectReply) {
 			IntegrationNamespaceUtils.setReferenceIfAttributeDefined(builder, element, "reply-channel");
 			IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "request-timeout");
@@ -136,18 +139,34 @@ public class HttpInboundEndpointParser extends AbstractSingleBeanDefinitionParse
 		}
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "supported-methods", "supportedMethodNames");
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "request-payload-type");
-		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "view-name");
+		String viewName = element.getAttribute("view-name");
+		String viewExpression = element.getAttribute("view-expression");
+		boolean hasViewName = StringUtils.hasText(viewName);
+		boolean hasViewExpression = StringUtils.hasText(viewExpression);
+		if (hasViewName ? hasViewExpression : false) {
+			parserContext.getReaderContext().error("Only one of 'view' or 'view-expression' is allowed", element);
+		}
+		if (hasViewName) {
+			RootBeanDefinition expressionDef = new RootBeanDefinition(LiteralExpression.class);
+			expressionDef.getConstructorArgumentValues().addGenericArgumentValue(viewName);
+			builder.addPropertyValue("viewExpression", expressionDef);
+		}
+		else if (hasViewExpression) {
+			RootBeanDefinition expressionDef = new RootBeanDefinition(ExpressionFactoryBean.class);
+			expressionDef.getConstructorArgumentValues().addGenericArgumentValue(viewExpression);
+			builder.addPropertyValue("viewExpression", expressionDef);
+		}
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "errors-key");
 		IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "error-code");
 		IntegrationNamespaceUtils.setReferenceIfAttributeDefined(builder, element, "message-converters");
-		
-		
+
+
 		//IntegrationNamespaceUtils.setReferenceIfAttributeDefined(builder, element, "header-mapper");
 		String headerMapper = element.getAttribute("header-mapper");
 		String mappedRequestHeaders = element.getAttribute("mapped-request-headers");
 		String mappedResponseHeaders = element.getAttribute("mapped-response-headers");
-		
-		
+
+
 		if (StringUtils.hasText(headerMapper)) {
 			if (StringUtils.hasText(mappedRequestHeaders) || StringUtils.hasText(mappedResponseHeaders)) {
 				parserContext.getReaderContext().error("Neither 'mappped-request-headers' or 'mapped-response-headers' " +
@@ -159,7 +178,7 @@ public class HttpInboundEndpointParser extends AbstractSingleBeanDefinitionParse
 			BeanDefinitionBuilder headerMapperBuilder = BeanDefinitionBuilder.genericBeanDefinition(
 									"org.springframework.integration.http.support.DefaultHttpHeaderMapper");
 			headerMapperBuilder.setFactoryMethod("inboundMapper");
-			
+
 			IntegrationNamespaceUtils.setValueIfAttributeDefined(headerMapperBuilder, element, "mapped-request-headers", "inboundHeaderNames");
 			IntegrationNamespaceUtils.setValueIfAttributeDefined(headerMapperBuilder, element, "mapped-response-headers", "outboundHeaderNames");
 			builder.addPropertyValue("headerMapper", headerMapperBuilder.getBeanDefinition());

spring-integration-http/src/main/java/org/springframework/integration/http/inbound/HttpRequestHandlingController.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.
@@ -24,9 +24,16 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.context.MessageSource;
+import org.springframework.expression.Expression;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
+import org.springframework.integration.Message;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 import org.springframework.validation.Errors;
 import org.springframework.validation.MapBindingResult;
 import org.springframework.web.servlet.ModelAndView;
+import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.mvc.Controller;
 
 /**
@@ -40,8 +47,9 @@ import org.springframework.web.servlet.mvc.Controller;
  * reply Message or payload depending on the value of {@link #extractReplyPayload} (true by default, meaning just the
  * payload). The corresponding key in the map is determined by the {@link #replyKey} property (with a default of
  * "reply").
- * 
+ *
  * @author Mark Fisher
+ * @author Gary Russell
  * @since 2.0
  */
 public class HttpRequestHandlingController extends HttpRequestHandlingEndpointSupport implements Controller {
@@ -52,7 +60,9 @@ public class HttpRequestHandlingController extends HttpRequestHandlingEndpointSu
 
 	private static final String DEFAULT_ERRORS_KEY = "errors";
 
-	private volatile String viewName;
+	private volatile Expression viewExpression;
+
+	private volatile StandardEvaluationContext evaluationContext;
 
 	private volatile String replyKey = DEFAULT_REPLY_KEY;
 
@@ -72,7 +82,8 @@ public class HttpRequestHandlingController extends HttpRequestHandlingEndpointSu
 	 * Specify the view name.
 	 */
 	public void setViewName(String viewName) {
-		this.viewName = viewName;
+		Assert.isTrue(StringUtils.hasText(viewName), "View name must contain text");
+		this.viewExpression = new LiteralExpression(viewName);
 	}
 
 	/**
@@ -98,13 +109,27 @@ public class HttpRequestHandlingController extends HttpRequestHandlingEndpointSu
 	 * provided in an object error to be optionally translated in the standard MVC way using a {@link MessageSource}.
 	 * The default value is <code>spring.integration.http.handler.error</code>. Three arguments are provided: the
 	 * exception, its message and its stack trace as a String.
-	 * 
+	 *
 	 * @param errorCode the error code to set
 	 */
 	public void setErrorCode(String errorCode) {
 		this.errorCode = errorCode;
 	}
 
+	/**
+	 * Specifies a SpEL expression to evaluate in order to generate the view name.
+	 * The EvaluationContext will be populated with the reply message as the root object,
+	 */
+	public void setViewExpression(Expression viewExpression) {
+		this.viewExpression = viewExpression;
+	}
+
+	@Override
+	protected void onInit() throws Exception {
+		super.onInit();
+		this.evaluationContext = this.createEvaluationContext();
+	}
+
 	/**
 	 * Handles the HTTP request by generating a Message and sending it to the request channel. If this gateway's
 	 * 'expectReply' property is true, it will also generate a response from the reply Message once received.
@@ -112,14 +137,30 @@ public class HttpRequestHandlingController extends HttpRequestHandlingEndpointSu
 	public final ModelAndView handleRequest(HttpServletRequest servletRequest, HttpServletResponse servletResponse)
 			throws Exception {
 		ModelAndView modelAndView = new ModelAndView();
-		if (this.viewName != null) {
-			modelAndView.setViewName(this.viewName);
-		}
 		try {
-			Object reply = super.doHandleRequest(servletRequest, servletResponse);
-			if (reply != null) {
+			Message<?> replyMessage = super.doHandleRequest(servletRequest, servletResponse);
+			if (replyMessage != null) {
+				Object reply = setupResponseAndConvertReply(servletResponse, replyMessage);
 				modelAndView.addObject(this.replyKey, reply);
 			}
+			if (this.viewExpression != null) {
+				Object view;
+				if (replyMessage != null) {
+					view = this.viewExpression.getValue(this.evaluationContext, replyMessage);
+				}
+				else {
+					view = this.viewExpression.getValue(this.evaluationContext);
+				}
+				if (view instanceof View) {
+					modelAndView.setView((View) view);
+				}
+				else if (view instanceof String) {
+					modelAndView.setViewName((String) view);
+				}
+				else {
+					throw new IllegalStateException("view expression must resolve to a View or String");
+				}
+			}
 		}
 		catch (Exception e) {
 			MapBindingResult errors = new MapBindingResult(new HashMap<String, Object>(), "dummy");

spring-integration-http/src/main/java/org/springframework/integration/http/inbound/HttpRequestHandlingEndpointSupport.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.
@@ -91,13 +91,14 @@ import org.springframework.web.util.UrlPathHelper;
  * In a request-reply scenario, the reply Message's payload will be extracted prior to generating a response by default.
  * To have the entire serialized Message available for the response, switch the {@link #extractReplyPayload} value to
  * <code>false</code>.
- * 
+ *
  * @author Mark Fisher
  * @author Oleg Zhurakousky
+ * @author Gary Russell
  * @since 2.0
  */
 abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySupport {
-	
+
 	private static final boolean jaxb2Present = ClassUtils.isPresent("javax.xml.bind.Binder",
 			HttpRequestHandlingEndpointSupport.class.getClassLoader());
 
@@ -105,7 +106,7 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 			HttpRequestHandlingEndpointSupport.class.getClassLoader())
 			&& ClassUtils.isPresent("org.codehaus.jackson.JsonGenerator", HttpRequestHandlingEndpointSupport.class
 					.getClassLoader());
-	
+
 	private static boolean romePresent = ClassUtils.isPresent("com.sun.syndication.feed.WireFeed",
 			HttpRequestHandlingEndpointSupport.class.getClassLoader());
 
@@ -128,7 +129,7 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 	private volatile boolean extractReplyPayload = true;
 
 	private volatile MultipartResolver multipartResolver;
-	
+
 	private volatile Expression payloadExpression;
 
 	private volatile Map<String, Expression> headerExpressions;
@@ -154,10 +155,10 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 		}
 		if (romePresent) {
 			this.messageConverters.add(new AtomFeedHttpMessageConverter());
-			this.messageConverters.add(new RssChannelHttpMessageConverter()); 	
+			this.messageConverters.add(new RssChannelHttpMessageConverter());
 		}
 	}
-	
+
 	/**
 	 * @return whether to expect reply
 	 */
@@ -167,12 +168,12 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 
 	/**
 	 * Set the path template for which this endpoint expects requests.
-	 * May include path variable {keys} to match against. 
+	 * May include path variable {keys} to match against.
 	 */
 	public void setPath(String path) {
 		this.path = path;
 	}
-	
+
 	String getPath() {
 		return path;
 	}
@@ -300,9 +301,10 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 	/**
 	 * Handles the HTTP request by generating a Message and sending it to the request channel. If this gateway's
 	 * 'expectReply' property is true, it will also generate a response from the reply Message once received.
+	 * @return a the response Message
 	 */
 	@SuppressWarnings({ "rawtypes", "unchecked" })
-	protected final Object doHandleRequest(HttpServletRequest servletRequest, HttpServletResponse servletResponse) throws IOException {
+	protected final Message<?> doHandleRequest(HttpServletRequest servletRequest, HttpServletResponse servletResponse) throws IOException {
 		try {
 			ServletServerHttpRequest request = this.prepareRequest(servletRequest);
 			if (!this.supportedMethods.contains(request.getMethod())) {
@@ -351,13 +353,13 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 
 			if (payload == null) {
 				if (requestBody != null) {
-					payload = requestBody;		
+					payload = requestBody;
 				}
 				else {
 					payload = requestParams;
 				}
 			}
-			
+
 			MessageBuilder<?> messageBuilder = null;
 
 			if (payload instanceof Message<?>){
@@ -366,28 +368,16 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 			else {
 				messageBuilder = MessageBuilder.withPayload(payload).copyHeaders(headers);
 			}
-			
+
 			Message<?> message = messageBuilder
 					.setHeader(org.springframework.integration.http.HttpHeaders.REQUEST_URL, request.getURI().toString())
 					.setHeader(org.springframework.integration.http.HttpHeaders.REQUEST_METHOD, request.getMethod().toString())
 					.setHeader(org.springframework.integration.http.HttpHeaders.USER_PRINCIPAL, servletRequest.getUserPrincipal())
 					.build();
-			
-			Object reply = null;
+
+			Message<?> reply = null;
 			if (this.expectReply) {
 				reply = this.sendAndReceiveMessage(message);
-				if (reply != null) {
-					ServletServerHttpResponse response = new ServletServerHttpResponse(servletResponse);
-					this.headerMapper.fromHeaders(((Message<?>) reply).getHeaders(), response.getHeaders());
-					HttpStatus httpStatus = this.resolveHttpStatusFromHeaders(((Message<?>) reply).getHeaders());
-					if (httpStatus != null) {
-						response.setStatusCode(httpStatus);
-					}	
-					response.close();
-					if (this.extractReplyPayload) {
-						reply = ((Message<?>) reply).getPayload();
-					}
-				}
 			}
 			else {
 				this.send(message);
@@ -399,6 +389,29 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 		}
 	}
 
+	/**
+	 * Converts the reply message to the appropriate HTTP reply object and
+	 * sets up the servlet response.
+	 * @param servletResponse The servlet response.
+	 * @param replyMessage The reply message.
+	 * @return The message payload (if {@link #extractReplyPayload}) otherwise the
+	 * message.
+	 */
+	protected final Object setupResponseAndConvertReply(HttpServletResponse servletResponse, Message<?> replyMessage) {
+		ServletServerHttpResponse response = new ServletServerHttpResponse(servletResponse);
+		this.headerMapper.fromHeaders(replyMessage.getHeaders(), response.getHeaders());
+		HttpStatus httpStatus = this.resolveHttpStatusFromHeaders(((Message<?>) replyMessage).getHeaders());
+		if (httpStatus != null) {
+			response.setStatusCode(httpStatus);
+		}
+		response.close();
+		Object reply = replyMessage;
+		if (this.extractReplyPayload) {
+			reply = replyMessage.getPayload();
+		}
+		return reply;
+	}
+
 	/**
 	 * Prepares an instance of {@link ServletServerHttpRequest} from the raw {@link HttpServletRequest}. Also converts
 	 * the request into a multipart request to make multiparts available if necessary. If no multipart resolver is set,
@@ -485,8 +498,8 @@ abstract class HttpRequestHandlingEndpointSupport extends MessagingGatewaySuppor
 		}
 		return httpStatus;
 	}
-	
-	private StandardEvaluationContext createEvaluationContext(){
+
+	protected StandardEvaluationContext createEvaluationContext(){
 		StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
 		evaluationContext.addPropertyAccessor(new MapAccessor());
 		BeanFactory beanFactory = this.getBeanFactory();

spring-integration-http/src/main/java/org/springframework/integration/http/inbound/HttpRequestHandlingMessagingGateway.java

@@ -29,6 +29,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.server.ServletServerHttpRequest;
 import org.springframework.http.server.ServletServerHttpResponse;
+import org.springframework.integration.Message;
 import org.springframework.integration.MessagingException;
 import org.springframework.integration.http.converter.MultipartAwareFormHttpMessageConverter;
 import org.springframework.util.CollectionUtils;
@@ -53,7 +54,7 @@ import org.springframework.web.HttpRequestHandler;
  * <p/>
  * By default a number of {@link HttpMessageConverter}s are already configured. The list can be overridden by calling
  * the {@link #setMessageConverters(List)} method.
- * 
+ *
  * @author Mark Fisher
  * @author Oleg Zhurakousky
  * @since 2.0
@@ -76,7 +77,7 @@ public class HttpRequestHandlingMessagingGateway extends HttpRequestHandlingEndp
 	 * Flag to determine if conversion and writing out of message handling exceptions should be attempted (default
 	 * false, in which case they will simply be re-thrown). If the flag is true and no message converter can convert the
 	 * exception a new exception will be thrown.
-	 * 
+	 *
 	 * @param convertExceptions the flag to set
 	 */
 	public void setConvertExceptions(boolean convertExceptions) {
@@ -91,8 +92,12 @@ public class HttpRequestHandlingMessagingGateway extends HttpRequestHandlingEndp
 	public final void handleRequest(HttpServletRequest servletRequest, HttpServletResponse servletResponse)
 			throws ServletException, IOException {
 		Object responseContent = null;
+		Message<?> responseMessage;
 		try {
-			responseContent = super.doHandleRequest(servletRequest, servletResponse);
+			responseMessage = super.doHandleRequest(servletRequest, servletResponse);
+			if (responseMessage != null) {
+				responseContent = setupResponseAndConvertReply(servletResponse, responseMessage);
+			}
 		}
 		catch (Exception e) {
 			responseContent = handleExceptionInternal(e);

spring-integration-http/src/main/resources/org/springframework/integration/http/config/spring-integration-http-2.2.xsd

@@ -191,6 +191,15 @@ The String "HTTP_REQUEST_HEADERS" will match against any of the standard HTTP Re
 							</xsd:documentation>
 						</xsd:annotation>
 					</xsd:attribute>
+					<xsd:attribute name="view-expression" type="xsd:string">
+						<xsd:annotation>
+							<xsd:documentation>
+								SpEL expression that resolves to a view to be resolved when rendering a response.
+								The expression can resolve to a view name or View object.
+								The root object of the evaluation context is the reply message.
+							</xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
 					<xsd:attribute name="errors-key" type="xsd:string">
 						<xsd:annotation>
 							<xsd:documentation>