REDIRECT AND FLASH ATTRIBUTE RELATED IMPROVEMENTS

Remove custom FlashMap extension.
Update FormController to use Spring 3.1 flash attributes.
Use @ModelAttribute method to pre-load "ajaxRequest" attribute.
USe @SessionAttribute to store "formBean" attribute in the session.
Add "Redirect" tab showing options for building the redirect URL.

Author: rstoyanchev

pom.xml

@@ -9,7 +9,7 @@
 	<version>1.0.0-BUILD-SNAPSHOT</version>
 	<properties>
 		<java-version>1.6</java-version>
-		<org.springframework-version>3.1.0.M2</org.springframework-version>
+		<org.springframework-version>3.1.0.BUILD-SNAPSHOT</org.springframework-version>
 		<org.aspectj-version>1.6.10</org.aspectj-version>
 		<org.slf4j-version>1.6.1</org.slf4j-version>
 	</properties>

src/main/java/org/springframework/mvc/extensions/flash/FlashMap.java

@@ -3,10 +3,9 @@
 import java.io.IOException;
 
 import org.springframework.mvc.extensions.ajax.AjaxUtils;
-import org.springframework.mvc.extensions.flash.FlashMap.Message;
-import org.springframework.mvc.extensions.flash.FlashMap.MessageType;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -17,17 +16,18 @@
 @RequestMapping("/fileupload")
 public class FileUploadController {
 
+	@ModelAttribute
+	public void ajaxAttribute(WebRequest request, Model model) {
+		model.addAttribute("ajaxRequest", AjaxUtils.isAjaxRequest(request));
+	}
+
 	@RequestMapping(method=RequestMethod.GET)
-	public void fileUploadForm(WebRequest webRequest, Model model) {
-		model.addAttribute("ajaxRequest", AjaxUtils.isAjaxRequest(webRequest));	
+	public void fileUploadForm() {
 	}
 
 	@RequestMapping(method=RequestMethod.POST)
-	public void processUpload(@RequestParam MultipartFile file, WebRequest webRequest, Model model) throws IOException {
-		String message = "File '" + file.getOriginalFilename() + "' uploaded successfully";
-		// prepare model for rendering success message in this request
-		model.addAttribute("message", new Message(MessageType.success, message));
-		model.addAttribute("ajaxRequest", AjaxUtils.isAjaxUploadRequest(webRequest));			
+	public void processUpload(@RequestParam MultipartFile file, Model model) throws IOException {
+		model.addAttribute("message", "File '" + file.getOriginalFilename() + "' uploaded successfully");
 	}
 
 }

src/main/java/org/springframework/mvc/extensions/flash/FlashMapFilter.java

@@ -1,49 +1,60 @@
 package org.springframework.samples.mvc.form;
 
-import javax.servlet.http.HttpSession;
 import javax.validation.Valid;
 
 import org.springframework.mvc.extensions.ajax.AjaxUtils;
-import org.springframework.mvc.extensions.flash.FlashMap;
-import org.springframework.mvc.extensions.flash.FlashMap.Message;
-import org.springframework.mvc.extensions.flash.FlashMap.MessageType;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
 import org.springframework.validation.BindingResult;
+import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.SessionAttributes;
 import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 
 @Controller
 @RequestMapping("/form")
+@SessionAttributes("formBean")
 public class FormController {
 
+	// Invoked on every request
+
+	@ModelAttribute
+	public void ajaxAttribute(WebRequest request, Model model) {
+		model.addAttribute("ajaxRequest", AjaxUtils.isAjaxRequest(request));
+	}
+
+	// Invoked initially to create the "form" attribute
+	// Once created the "form" attribute comes from the HTTP session (see @SessionAttributes)
+
+	@ModelAttribute("formBean")
+	public FormBean createFormBean() {
+		return new FormBean();
+	}
+	
 	@RequestMapping(method=RequestMethod.GET)
-	public void form(WebRequest webRequest, HttpSession session, Model model) {
-		FormBean form = (FormBean) session.getAttribute("form");
-		model.addAttribute(form != null ? form : new FormBean());
-		model.addAttribute("ajaxRequest", AjaxUtils.isAjaxRequest(webRequest));
+	public void form() {
 	}
 
 	@RequestMapping(method=RequestMethod.POST)
-	public String processSubmit(@Valid FormBean form, BindingResult result, WebRequest webRequest, HttpSession session, Model model) {
+	public String processSubmit(@Valid FormBean formBean, BindingResult result, boolean ajaxRequest, 
+			Model model, RedirectAttributes redirectAttrs) {
 		if (result.hasErrors()) {
-			model.addAttribute("ajaxRequest", AjaxUtils.isAjaxRequest(webRequest));
 			return null;
 		}
-		// simply store form bean in the session for demo purposes, typically you would save form bean values to a db
-		session.setAttribute("form", form);
-		String message = "Form submitted successfully.  Bound " + form;
-		// success response handling
-		if (AjaxUtils.isAjaxRequest(webRequest)) {
+		// Typically you would save to a db and clear the "form" attribute from the session 
+		// via SessionStatus.setCompleted(). For the demo we leave it in the session.
+		String message = "Form submitted successfully.  Bound " + formBean;
+		// Success response handling
+		if (ajaxRequest) {
 			// prepare model for rendering success message in this request
-			model.addAttribute("message", new Message(MessageType.success, message));
-			model.addAttribute("ajaxRequest", true);
+			model.addAttribute("message", message);
 			return null;
 		} else {
 			// store a success message for rendering on the next request after redirect
-			FlashMap.setSuccessMessage(message);
 			// redirect back to the form to render the success message along with newly bound values
+			redirectAttrs.addFlashAttribute("message", message);
 			return "redirect:/form";			
 		}
 	}

src/main/java/org/springframework/samples/mvc/fileupload/FileUploadController.java

@@ -0,0 +1,47 @@
+package org.springframework.samples.mvc.redirect;
+
+import javax.inject.Inject;
+
+import org.joda.time.LocalDate;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
+import org.springframework.web.util.UriComponents;
+import org.springframework.web.util.UriComponentsBuilder;
+
+@Controller
+@RequestMapping("/redirect")
+public class RedirectController {
+	
+	private final ConversionService conversionService;
+
+	@Inject
+	public RedirectController(ConversionService conversionService) {
+		this.conversionService = conversionService;
+	}
+
+	@RequestMapping(value="/uriTemplate", method=RequestMethod.GET)
+	public String uriTemplate(RedirectAttributes redirectAttrs) {
+		redirectAttrs.addAttribute("account", "a123");  // Used as URI template variable
+		redirectAttrs.addAttribute("date", new LocalDate(2011, 12, 31));  // Appended as a query parameter
+		return "redirect:/redirect/{account}";
+	}
+
+	@RequestMapping(value="/uriComponentsBuilder", method=RequestMethod.GET)
+	public String uriComponentsBuilder() {
+		String date = this.conversionService.convert(new LocalDate(2011, 12, 31), String.class);
+		UriComponents redirectUri = UriComponentsBuilder.fromPath("/redirect/{account}").queryParam("date", date)
+				.build().expand("a123").encode();
+		return "redirect:" + redirectUri.toUriString();
+	}
+
+	@RequestMapping(value="/{account}", method=RequestMethod.GET)
+	public String show(@PathVariable String account, @RequestParam(required=false) LocalDate date) {
+		return "redirect/redirectResults";
+	}
+
+}

src/main/java/org/springframework/samples/mvc/form/FormController.java

@@ -25,13 +25,16 @@ public void usingRequestToViewNameTranslator(Model model) {
 		model.addAttribute("fruit", "apple");
 	}
 
-	@RequestMapping(value="pathVars/{foo}/{fruit}", method=RequestMethod.GET)
+	@RequestMapping(value="pathVariables/{foo}/{fruit}", method=RequestMethod.GET)
 	public String pathVars(@PathVariable String foo, @PathVariable String fruit) {
+		// No need to add @PathVariables "foo" and "fruit" to the model
+		// They will be merged in the model before rendering
 		return "views/html";
 	}
 
 	@RequestMapping(value="dataBinding/{foo}/{fruit}", method=RequestMethod.GET)
 	public String dataBinding(@Valid JavaBean javaBean, Model model) {
+		// JavaBean "foo" and "fruit" properties populated from URI variables 
 		return "views/dataBinding";
 	}
 

src/main/java/org/springframework/samples/mvc/redirect/RedirectController.java

@@ -27,7 +27,7 @@
 	<!-- Only needed because we install custom converters to support the examples in the org.springframewok.samples.mvc.convert package -->
 	<beans:bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
 		<beans:property name="formatters">
-			<beans:bean class="org.springframework.samples.mvc.convert.MaskFormatAnnotationFormatterFactory" />
+            <beans:bean class="org.springframework.samples.mvc.convert.MaskFormatAnnotationFormatterFactory" />
 		</beans:property>
 	</beans:bean>
 

src/main/java/org/springframework/samples/mvc/views/ViewsController.java

@@ -18,7 +18,7 @@
 			<div class="header">
 		  		<h2>Form</h2>
 		  		<c:if test="${not empty message}">
-					<div id="message" class="${message.type}">${message.text}</div>	  		
+					<div id="message" class="success">${message}</div>	  		
 		  		</c:if>
 			</div>
 			<label for="file">File</label>

src/main/webapp/WEB-INF/spring/appServlet/servlet-context.xml

@@ -20,7 +20,7 @@
 			<div class="header">
 		  		<h2>Form</h2>
 		  		<c:if test="${not empty message}">
-					<div id="message" class="${message.type}">${message.text}</div>	
+					<div id="message" class="success">${message}</div>	
 		  		</c:if>
 		  		<s:bind path="*">
 		  			<c:if test="${status.error}">