Add value() attribute to @Payload

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/Payload.java

@@ -38,6 +38,16 @@ import org.springframework.messaging.support.converter.MessageConverter;
 @Documented
 public @interface Payload {
 
+	/**
+	 * A SpEL expression to be evaluated against the payload object as the root context.
+	 * This attribute may or may not be supported depending on whether the message being
+	 * handled contains a non-primitive Object as its payload or is in serialized form
+	 * and requires message conversion.
+	 * <p>
+	 * When processing STOMP over WebSocket messages this attribute is not supported.
+	 */
+	String value() default "";
+
 	/**
 	 * Whether payload content is required.
 	 * <p>

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/PayloadArgumentResolver.java

@@ -23,6 +23,7 @@ import org.springframework.messaging.handler.method.HandlerMethodArgumentResolve
 import org.springframework.messaging.support.converter.MessageConverter;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.StringUtils;
 
 
 /**
@@ -69,6 +70,10 @@ public class PayloadArgumentResolver implements HandlerMethodArgumentResolver {
 			}
 		}
 
+		if ((annot != null) && StringUtils.hasText(annot.value())) {
+			throw new IllegalStateException("@Payload SpEL expressions not supported by this resolver.");
+		}
+
 		return this.converter.fromMessage(message, targetClass);
 	}
 

spring-messaging/src/test/java/org/springframework/messaging/handler/annotation/support/PayloadArgumentResolverTests.java

@@ -41,6 +41,7 @@ public class PayloadArgumentResolverTests {
 
 	private MethodParameter param;
 	private MethodParameter paramNotRequired;
+	private MethodParameter paramWithSpelExpression;
 
 
 	@Before
@@ -50,10 +51,11 @@ public class PayloadArgumentResolverTests {
 		this.resolver = new PayloadArgumentResolver(messageConverter );
 
 		Method method = PayloadArgumentResolverTests.class.getDeclaredMethod("handleMessage",
-				String.class, String.class);
+				String.class, String.class, String.class);
 
 		this.param = new MethodParameter(method , 0);
 		this.paramNotRequired = new MethodParameter(method , 1);
+		this.paramWithSpelExpression = new MethodParameter(method , 2);
 	}
 
 
@@ -75,11 +77,18 @@ public class PayloadArgumentResolverTests {
 		assertEquals("ABC", this.resolver.resolveArgument(this.paramNotRequired, notEmptyMessage));
 	}
 
+	@Test(expected=IllegalStateException.class)
+	public void resolveSpelExpressionNotSupported() throws Exception {
+		Message<?> message = MessageBuilder.withPayload("ABC".getBytes()).build();
+		this.resolver.resolveArgument(this.paramWithSpelExpression, message);
+	}
+
 
 	@SuppressWarnings("unused")
 	private void handleMessage(
 			@Payload String param,
-			@Payload(required=false) String paramNotRequired) {
+			@Payload(required=false) String paramNotRequired,
+			@Payload("foo.bar") String paramWithSpelExpression) {
 	}
 
 }