Introduce alias for 'value' attribute in @MatrixVariable

Issue: SPR-11393

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -22,6 +22,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.springframework.core.annotation.AliasFor;
+
 /**
  * Annotation which indicates that a method parameter should be bound to a
  * name-value pair within a path segment. Supported for {@link RequestMapping}
@@ -37,6 +39,7 @@ import java.lang.annotation.Target;
  * matrix variable names and values.
  *
  * @author Rossen Stoyanchev
+ * @author Sam Brannen
  * @since 3.2
  */
 @Target(ElementType.PARAMETER)
@@ -45,10 +48,19 @@ import java.lang.annotation.Target;
 public @interface MatrixVariable {
 
 	/**
-	 * The name of the matrix variable.
+	 * Alias for {@link #name}.
 	 */
+	@AliasFor(attribute = "name")
 	String value() default "";
 
+	/**
+	 * The name of the matrix variable.
+	 * @since 4.2
+	 * @see #value
+	 */
+	@AliasFor(attribute = "value")
+	String name() default "";
+
 	/**
 	 * The name of the URI path variable where the matrix variable is located,
 	 * if necessary for disambiguation (e.g. a matrix variable with the same
@@ -58,17 +70,18 @@ public @interface MatrixVariable {
 
 	/**
 	 * Whether the matrix variable is required.
-	 * <p>Default is {@code true}, leading to an exception thrown in case
-	 * of the variable missing in the request. Switch this to {@code false}
-	 * if you prefer a {@code null} in case of the variable missing.
-	 * <p>Alternatively, provide a {@link #defaultValue() defaultValue},
-	 * which implicitly sets this flag to {@code false}.
+	 * <p>Default is {@code true}, leading to an exception being thrown in
+	 * case the variable is missing in the request. Switch this to {@code false}
+	 * if you prefer a {@code null} if the variable is missing.
+	 * <p>Alternatively, provide a {@link #defaultValue}, which implicitly sets
+	 * this flag to {@code false}.
 	 */
 	boolean required() default true;
 
 	/**
-	 * The default value to use as a fallback. Supplying a default value implicitly
-	 * sets {@link #required()} to false.
+	 * The default value to use as a fallback.
+	 * <p>Supplying a default value implicitly sets {@link #required} to
+	 * {@code false}.
 	 */
 	String defaultValue() default ValueConstants.DEFAULT_NONE;
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/MatrixVariableMapMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * 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.
@@ -35,8 +35,8 @@ import org.springframework.web.servlet.HandlerMapping;
 
 /**
  * Resolves method arguments of type Map annotated with
- * {@link MatrixVariable @MatrixVariable} where the annotation the does not
- * specify a name. If a name specified then the argument will by resolved by the
+ * {@link MatrixVariable @MatrixVariable} where the annotation does not
+ * specify a name. If a name is specified then the argument will by resolved by the
  * {@link MatrixVariableMethodArgumentResolver} instead.
  *
  * @author Rossen Stoyanchev
@@ -46,10 +46,10 @@ public class MatrixVariableMapMethodArgumentResolver implements HandlerMethodArg
 
 	@Override
 	public boolean supportsParameter(MethodParameter parameter) {
-		MatrixVariable paramAnnot = parameter.getParameterAnnotation(MatrixVariable.class);
-		if (paramAnnot != null) {
+		MatrixVariable matrixVariable = parameter.getParameterAnnotation(MatrixVariable.class);
+		if (matrixVariable != null) {
 			if (Map.class.isAssignableFrom(parameter.getParameterType())) {
-				return !StringUtils.hasText(paramAnnot.value());
+				return !StringUtils.hasText(matrixVariable.name());
 			}
 		}
 		return false;

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/MatrixVariableMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -33,12 +33,13 @@ import org.springframework.web.method.annotation.AbstractNamedValueMethodArgumen
 import org.springframework.web.servlet.HandlerMapping;
 
 /**
- * Resolves method arguments annotated with an {@link MatrixVariable @PathParam}.
+ * Resolves method arguments annotated with {@link MatrixVariable @MatrixVariable}.
  *
  * <p>If the method parameter is of type Map and no name is specified, then it will
  * by resolved by the {@link MatrixVariableMapMethodArgumentResolver} instead.
  *
  * @author Rossen Stoyanchev
+ * @author Sam Brannen
  * @since 3.2
  */
 public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver {
@@ -53,8 +54,8 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 			return false;
 		}
 		if (Map.class.isAssignableFrom(parameter.getParameterType())) {
-			String paramName = parameter.getParameterAnnotation(MatrixVariable.class).value();
-			return StringUtils.hasText(paramName);
+			String variableName = parameter.getParameterAnnotation(MatrixVariable.class).name();
+			return StringUtils.hasText(variableName);
 		}
 		return true;
 	}
@@ -62,7 +63,7 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 	@Override
 	protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
 		MatrixVariable annotation = parameter.getParameterAnnotation(MatrixVariable.class);
-		return new PathParamNamedValueInfo(annotation);
+		return new MatrixVariableNamedValueInfo(annotation);
 	}
 
 	@Override
@@ -120,10 +121,10 @@ public class MatrixVariableMethodArgumentResolver extends AbstractNamedValueMeth
 	}
 
 
-	private static class PathParamNamedValueInfo extends NamedValueInfo {
+	private static class MatrixVariableNamedValueInfo extends NamedValueInfo {
 
-		private PathParamNamedValueInfo(MatrixVariable annotation) {
-			super(annotation.value(), annotation.required(), annotation.defaultValue());
+		private MatrixVariableNamedValueInfo(MatrixVariable annotation) {
+			super(annotation.name(), annotation.required(), annotation.defaultValue());
 		}
 	}
 }

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

@@ -1,5 +1,5 @@
 /*
- * 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.
@@ -152,7 +152,7 @@ public class MatrixVariablesMethodArgumentResolverTests {
 	public void handle(
 			String stringArg,
 			@MatrixVariable List<String> colors,
-			@MatrixVariable(value="year", pathVar="cars", required=false, defaultValue="2013") int preferredYear) {
+			@MatrixVariable(name = "year", pathVar = "cars", required = false, defaultValue = "2013") int preferredYear) {
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * 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.
@@ -397,8 +397,8 @@ public class UriTemplateServletAnnotationControllerHandlerMethodTests extends Ab
 		public void handle(@PathVariable("hotel") String hotel,
 				@PathVariable int booking,
 				@PathVariable String other,
-				@MatrixVariable(value="q", pathVar="hotel") int qHotel,
-				@MatrixVariable(value="q", pathVar="other") int qOther,
+				@MatrixVariable(name = "q", pathVar = "hotel") int qHotel,
+				@MatrixVariable(name = "q", pathVar = "other") int qOther,
 				Writer writer) throws IOException {
 			assertEquals("Invalid path variable value", "42", hotel);
 			assertEquals("Invalid path variable value", 21, booking);