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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.tuscany.das.rdb;
+
+import commonj.sdo.DataObject;
+
+/**
+ * An iterator-like interface to conveniently move through chunks of data. The 
+ * idea is that a Pager works with a read Command. The read command
+ * returns a large amount of data and the client wants to work with chunks 
+ * of it at a time. So the Pager is created on the command and each call to
+ * next returns the next chunk of data. This is done completely disconnected. 
+ * No cursor is maintained between calls to #next.
+ * 
+ * TODO - This is very preliminary. We need to look at this interface 
+ * in the context of disonnected scenarios such as a web app. The Pager instance
+ * will probably be saved in session so it must be very light and cannot 
+ * reference a connection. Also, we probably need to define a factory or add a
+ * method to set page size.
+ * 
+ * 
+ */
+public interface Pager {
+
+    /**
+     * Get the next page of data
+     * 
+     * @return the next page of data
+     */
+    DataObject next();
+
+    /**
+     * Get the page prior to the last page returned
+     * 
+     * @return the previous page
+     */
+    DataObject previous();
+
+    /**
+     * Return a specific identified page.
+     * 
+     * @param page
+     *            The number of the page to return
+     * @return the indicated page
+     */
+    DataObject getPage(int page);
+
+}