From a173c78d989d1c70fd63625fb678e16a18312b88 Mon Sep 17 00:00:00 2001
From: Rossen Stoyanchev <rstoyanchev@pivotal.io>
Date: Tue, 19 Apr 2016 17:34:08 -0400
Subject: [PATCH] Add getAttribute to WebSession and ServerWebExchange

---
 .../springframework/web/server/ServerWebExchange.java    | 9 +++++++++
 .../java/org/springframework/web/server/WebSession.java  | 9 +++++++++
 .../web/server/adapter/DefaultServerWebExchange.java     | 6 ++++++
 .../web/server/session/DefaultWebSession.java            | 6 ++++++
 4 files changed, 30 insertions(+)

diff --git a/spring-web-reactive/src/main/java/org/springframework/web/server/ServerWebExchange.java b/spring-web-reactive/src/main/java/org/springframework/web/server/ServerWebExchange.java
index 144cc81953..a2b3857c1d 100644
--- a/spring-web-reactive/src/main/java/org/springframework/web/server/ServerWebExchange.java
+++ b/spring-web-reactive/src/main/java/org/springframework/web/server/ServerWebExchange.java
@@ -16,6 +16,7 @@
 package org.springframework.web.server;
 
 import java.util.Map;
+import java.util.Optional;
 
 import reactor.core.publisher.Mono;
 
@@ -46,6 +47,14 @@ public interface ServerWebExchange {
 	 */
 	Map<String, Object> getAttributes();
 
+	/**
+	 * Return the request attribute value if present.
+	 * @param name the attribute name
+	 * @param <T> the attribute type
+	 * @return the attribute value
+	 */
+	<T> Optional<T> getAttribute(String name);
+
 	/**
 	 * Return the web session for the current request. Always guaranteed  to
 	 * return an instance either matching to the session id requested by the
diff --git a/spring-web-reactive/src/main/java/org/springframework/web/server/WebSession.java b/spring-web-reactive/src/main/java/org/springframework/web/server/WebSession.java
index ca6554cbcf..136daccc15 100644
--- a/spring-web-reactive/src/main/java/org/springframework/web/server/WebSession.java
+++ b/spring-web-reactive/src/main/java/org/springframework/web/server/WebSession.java
@@ -18,6 +18,7 @@ package org.springframework.web.server;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Map;
+import java.util.Optional;
 
 import reactor.core.publisher.Mono;
 
@@ -44,6 +45,14 @@ public interface WebSession {
 	 */
 	Map<String, Object> getAttributes();
 
+	/**
+	 * Return the attribute value if present.
+	 * @param name the attribute name
+	 * @param <T> the attribute type
+	 * @return the attribute value
+	 */
+	<T> Optional<T> getAttribute(String name);
+
 	/**
 	 * Force the creation of a session causing the session id to be sent when
 	 * {@link #save()} is called.
diff --git a/spring-web-reactive/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java b/spring-web-reactive/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java
index ee6decb2eb..8e9807491c 100644
--- a/spring-web-reactive/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java
+++ b/spring-web-reactive/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java
@@ -16,6 +16,7 @@
 package org.springframework.web.server.adapter;
 
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 
 import reactor.core.publisher.EmitterProcessor;
@@ -78,6 +79,11 @@ public class DefaultServerWebExchange implements ServerWebExchange {
 		return this.attributes;
 	}
 
+	@Override @SuppressWarnings("unchecked")
+	public <T> Optional<T> getAttribute(String name) {
+		return Optional.ofNullable((T) this.attributes.get(name));
+	}
+
 	@Override
 	public Mono<WebSession> getSession() {
 		if (this.sessionMono == null) {
diff --git a/spring-web-reactive/src/main/java/org/springframework/web/server/session/DefaultWebSession.java b/spring-web-reactive/src/main/java/org/springframework/web/server/session/DefaultWebSession.java
index 0301563994..146c4e0a8e 100644
--- a/spring-web-reactive/src/main/java/org/springframework/web/server/session/DefaultWebSession.java
+++ b/spring-web-reactive/src/main/java/org/springframework/web/server/session/DefaultWebSession.java
@@ -20,6 +20,7 @@ import java.time.Clock;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
@@ -101,6 +102,11 @@ public class DefaultWebSession implements ConfigurableWebSession, Serializable {
 		return this.attributes;
 	}
 
+	@Override @SuppressWarnings("unchecked")
+	public <T> Optional<T> getAttribute(String name) {
+		return Optional.ofNullable((T) this.attributes.get(name));
+	}
+
 	@Override
 	public Instant getCreationTime() {
 		return this.creationTime;