SPR-6421, conversation store

org.springframework.web/src/main/java/org/springframework/web/context/conversation/WebBasedConversationStore.java

+/*
+ * Copyright 2002-2008 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. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package org.springframework.web.context.conversation;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.conversation.Conversation;
+import org.springframework.conversation.manager.AbstractThreadBackedConversationStore;
+import org.springframework.conversation.manager.ConversationStore;
+import org.springframework.web.context.request.RequestAttributes;
+import org.springframework.web.context.request.RequestContextHolder;
+
+/**
+ * A conversation store implementation ({@link ConversationStore}) based on a
+ * web environment where the conversations are most likely to be stored in the
+ * current session. It is based on the
+ * {@link AbstractThreadBackedConversationStore} implementation in order to be
+ * used outside a web thread as well.
+ * 
+ * @author Micha Kiener
+ * @since 3.1
+ */
+public class WebBasedConversationStore extends
+		AbstractThreadBackedConversationStore {
+	/** The name of the attribute for the conversation map within the session. */
+	public static final String CONVERSATION_STORE_ATTR_NAME = WebBasedConversationStore.class
+			.getName();
+
+	/**
+	 * This implementation uses the {@link RequestContextHolder} to get access
+	 * to the currently exposed session where the conversation map is stored
+	 * within.
+	 * 
+	 * @see org.springframework.conversation.manager.AbstractConversationStore#getConversationMap()
+	 */
+	@SuppressWarnings("unchecked")
+	@Override
+	public Map<String, Conversation> getConversationMap() {
+		RequestAttributes attributes = RequestContextHolder
+				.currentRequestAttributes();
+		Map<String, Conversation> conversationMap = (Map<String, Conversation>) attributes
+				.getAttribute(CONVERSATION_STORE_ATTR_NAME,
+						RequestAttributes.SCOPE_GLOBAL_SESSION);
+
+		if (conversationMap == null) {
+			conversationMap = new HashMap<String, Conversation>();
+			attributes.setAttribute(CONVERSATION_STORE_ATTR_NAME,
+					conversationMap, RequestAttributes.SCOPE_GLOBAL_SESSION);
+		}
+
+		return conversationMap;
+	}
+}