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Diffstat (limited to 'sca-java-1.x/tags/java-M1-final/java/das/rdb/src/main/java/org/apache/tuscany/das/rdb/Pager.java')
-rw-r--r-- | sca-java-1.x/tags/java-M1-final/java/das/rdb/src/main/java/org/apache/tuscany/das/rdb/Pager.java | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/java-M1-final/java/das/rdb/src/main/java/org/apache/tuscany/das/rdb/Pager.java b/sca-java-1.x/tags/java-M1-final/java/das/rdb/src/main/java/org/apache/tuscany/das/rdb/Pager.java new file mode 100644 index 0000000000..4edb447e31 --- /dev/null +++ b/sca-java-1.x/tags/java-M1-final/java/das/rdb/src/main/java/org/apache/tuscany/das/rdb/Pager.java @@ -0,0 +1,62 @@ +/** + * + * Copyright 2005 The Apache Software Foundation or its licensors, as applicable. + * + * 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.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 + */ + public DataObject next(); + + /** + * Get the page prior to the last page returned + * + * @return the previous page + */ + public DataObject previous(); + + /** + * Return a specific identified page. + * + * @param page + * The number of the page to return + * @return the indicated page + */ + public DataObject getPage(int page); + +} |