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Diffstat (limited to 'sandbox/lresende/das/api/src/main/java/org/apache/tuscany/das/Pager.java')
-rw-r--r-- | sandbox/lresende/das/api/src/main/java/org/apache/tuscany/das/Pager.java | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/sandbox/lresende/das/api/src/main/java/org/apache/tuscany/das/Pager.java b/sandbox/lresende/das/api/src/main/java/org/apache/tuscany/das/Pager.java new file mode 100644 index 0000000000..4a4ac1cae7 --- /dev/null +++ b/sandbox/lresende/das/api/src/main/java/org/apache/tuscany/das/Pager.java @@ -0,0 +1,64 @@ +/* + * 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; + +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); + +} |