Introduce alias for 'value' attribute in @SessionAttributes

Issue: SPR-11393

spring-web/src/main/java/org/springframework/web/bind/annotation/SessionAttributes.java

 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -23,11 +23,14 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.springframework.core.annotation.AliasFor;
+
 /**
- * Annotation that indicates the session attributes that a specific handler
- * uses. This will typically list the names of model attributes which should be
+ * Annotation that indicates the session attributes that a specific handler uses.
+ *
+ * <p>This will typically list the names of model attributes which should be
  * transparently stored in the session or some conversational storage,
- * serving as form-backing beans. <b>Declared at the type level,</b> applying
+ * serving as form-backing beans. <b>Declared at the type level</b>, applying
  * to the model attributes that the annotated handler class operates on.
  *
  * <p><b>NOTE:</b> Session attributes as indicated using this annotation
@@ -44,11 +47,12 @@ import java.lang.annotation.Target;
  * generic {@link org.springframework.web.context.request.WebRequest} interface.
  *
  * <p><b>NOTE:</b> When using controller interfaces (e.g. for AOP proxying),
- * make sure to consistently put <i>all</i> your mapping annotations - such as
- * {@code @RequestMapping} and {@code @SessionAttributes} - on
+ * make sure to consistently put <i>all</i> your mapping annotations &mdash;
+ * such as {@code @RequestMapping} and {@code @SessionAttributes} &mdash; on
  * the controller <i>interface</i> rather than on the implementation class.
  *
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @since 2.5
  */
 @Target({ElementType.TYPE})
@@ -58,18 +62,28 @@ import java.lang.annotation.Target;
 public @interface SessionAttributes {
 
 	/**
-	 * The names of session attributes in the model, to be stored in the
-	 * session or some conversational storage.
-	 * <p>Note: This indicates the model attribute names. The session attribute
-	 * names may or may not match the model attribute names; applications should
-	 * not rely on the session attribute names but rather operate on the model only.
+	 * Alias for {@link #names}.
 	 */
+	@AliasFor(attribute = "names")
 	String[] value() default {};
 
 	/**
-	 * The types of session attributes in the model, to be stored in the
-	 * session or some conversational storage. All model attributes of this
-	 * type will be stored in the session, regardless of attribute name.
+	 * The names of session attributes in the model that should be stored in the
+	 * session or some conversational storage.
+	 * <p><strong>Note</strong>: This indicates the <em>model attribute names</em>.
+	 * The <em>session attribute names</em> may or may not match the model attribute
+	 * names. Applications should therefore not rely on the session attribute
+	 * names but rather operate on the model only.
+	 * @since 4.2
+	 */
+	@AliasFor(attribute = "value")
+	String[] names() default {};
+
+	/**
+	 * The types of session attributes in the model that should be stored in the
+	 * session or some conversational storage.
+	 * <p>All model attributes of these types will be stored in the session,
+	 * regardless of attribute name.
 	 */
 	Class<?>[] types() default {};
 

spring-web/src/main/java/org/springframework/web/bind/annotation/support/HandlerMethodResolver.java

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -107,7 +107,7 @@ public class HandlerMethodResolver {
 		SessionAttributes sessionAttributes = AnnotationUtils.findAnnotation(handlerType, SessionAttributes.class);
 		this.sessionAttributesFound = (sessionAttributes != null);
 		if (this.sessionAttributesFound) {
-			this.sessionAttributeNames.addAll(Arrays.asList(sessionAttributes.value()));
+			this.sessionAttributeNames.addAll(Arrays.asList(sessionAttributes.names()));
 			this.sessionAttributeTypes.addAll(Arrays.asList(sessionAttributes.types()));
 		}
 	}

spring-web/src/main/java/org/springframework/web/method/annotation/SessionAttributesHandler.java

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -70,8 +70,8 @@ public class SessionAttributesHandler {
 
 		SessionAttributes annotation = AnnotationUtils.findAnnotation(handlerType, SessionAttributes.class);
 		if (annotation != null) {
-			this.attributeNames.addAll(Arrays.asList(annotation.value()));
-			this.attributeTypes.addAll(Arrays.<Class<?>>asList(annotation.types()));
+			this.attributeNames.addAll(Arrays.asList(annotation.names()));
+			this.attributeTypes.addAll(Arrays.asList(annotation.types()));
 		}
 
 		for (String attributeName : this.attributeNames) {

spring-web/src/test/java/org/springframework/web/method/annotation/SessionAttributesHandlerTests.java

 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -16,9 +16,9 @@
 
 package org.springframework.web.method.annotation;
 
+
 import java.util.HashSet;
 
-import org.junit.Before;
 import org.junit.Test;
 
 import org.springframework.mock.web.test.MockHttpServletRequest;
@@ -40,20 +40,13 @@ import static org.junit.Assert.*;
  */
 public class SessionAttributesHandlerTests {
 
-	private Class<?> handlerType = SessionAttributeHandler.class;
-
-	private SessionAttributesHandler sessionAttributesHandler;
+	private final SessionAttributeStore sessionAttributeStore = new DefaultSessionAttributeStore();
 
-	private SessionAttributeStore sessionAttributeStore;
+	private final SessionAttributesHandler sessionAttributesHandler = new SessionAttributesHandler(
+		SessionAttributeHandler.class, sessionAttributeStore);
 
-	private NativeWebRequest request;
+	private final NativeWebRequest request = new ServletWebRequest(new MockHttpServletRequest());
 
-	@Before
-	public void setUp() {
-		this.sessionAttributeStore = new DefaultSessionAttributeStore();
-		this.sessionAttributesHandler = new SessionAttributesHandler(handlerType, sessionAttributeStore);
-		this.request = new ServletWebRequest(new MockHttpServletRequest());
-	}
 
 	@Test
 	public void isSessionAttribute() throws Exception {
@@ -115,7 +108,8 @@ public class SessionAttributesHandlerTests {
 		assertTrue(sessionAttributeStore.retrieveAttribute(request, "attr3") instanceof TestBean);
 	}
 
-	@SessionAttributes(value = { "attr1", "attr2" }, types = { TestBean.class })
+
+	@SessionAttributes(names = { "attr1", "attr2" }, types = { TestBean.class })
 	private static class SessionAttributeHandler {
 	}
 

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java

@@ -2163,7 +2163,7 @@ public class ServletAnnotationControllerTests {
 
 	@Controller
 	@RequestMapping("/myPage")
-	@SessionAttributes({"object1", "object2"})
+	@SessionAttributes(names = { "object1", "object2" })
 	public static class MySessionAttributesController {
 
 		@RequestMapping(method = RequestMethod.GET)

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/ServletAnnotationControllerHandlerMethodTests.java

@@ -1774,7 +1774,7 @@ public class ServletAnnotationControllerHandlerMethodTests extends AbstractServl
 
 	@Controller
 	@RequestMapping("/myPage")
-	@SessionAttributes({"object1", "object2"})
+	@SessionAttributes(names = { "object1", "object2" })
 	public static class MySessionAttributesController {
 
 		@RequestMapping(method = RequestMethod.GET)