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/* * Copyright 2014-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. * A copy of the License is located at * * http://aws.amazon.com/apache2.0 * * or in the "license" file accompanying this file. This file 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 com.amazonaws.services.dynamodbv2.document; import com.amazonaws.services.dynamodbv2.document.internal.PageBasedCollection; import com.amazonaws.services.dynamodbv2.document.internal.PageIterable; /** * A collection of <code>Table</code>'s (initialized with the respective table * names). * * An <code>TableCollection</code> object maintains a cursor pointing to its * current pages of data. Initially the cursor is positioned before the first * page. The next method moves the cursor to the next row, and because it * returns false when there are no more rows in the <code>TableCollection</code> * object, it can be used in a while loop to iterate through the collection. * * Network calls can be triggered when the collection is iterated across page * boundaries. * * @param <R> low level result type */ public abstract class TableCollection<R> extends PageBasedCollection<Table, R> { // Overriding these just so javadocs will show up. /** * Returns an {@code Iterable<Page<Table, R>>} that iterates over pages of * tables from this collection. Each call to {@code Iterator.next} on an * {@code Iterator} returned from this {@code Iterable} results in exactly * one call to DynamoDB to retrieve a single page of results. * <p> * <code> * TableCollection<?> collection = ...; * for (Page<Table> page : collection.pages()) { * processTables(page); * } * </code> * <p> * The use of the internal/undocumented {@code PageIterable} class instead * of {@code Iterable} in the public interface here is retained for * backwards compatibility. It doesn't expose any methods beyond those * of the {@code Iterable} interface. This method will be changed to return * an {@code Iterable<Page<Table, R>>} directly in a future release of the * SDK. * * @see Page */ @Override public PageIterable<Table, R> pages() { return super.pages(); } /** * Returns the maximum number of resources to be retrieved in this * collection; or null if there is no limit. */ @Override public abstract Integer getMaxResultSize(); /** * Returns the low-level result last retrieved (for the current page) from * the server side; or null if there has yet no calls to the server. */ @Override public R getLastLowLevelResult() { return super.getLastLowLevelResult(); } /** * Used to register a listener for the event of receiving a low-level result * from the server side. * * @param listener * listener to be registered. If null, a "none" listener will be * set. * @return the previously registered listener. The return value is never * null. */ @Override public LowLevelResultListener<R> registerLowLevelResultListener(LowLevelResultListener<R> listener) { return super.registerLowLevelResultListener(listener); } }