| /** |
| * 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.gora.query; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| |
| import org.apache.gora.persistency.Persistent; |
| import org.apache.gora.store.DataStore; |
| |
| /** |
| * A result to a {@link Query}. Objects in the result set can be |
| * iterated by calling {@link #next()}, {@link #get()} |
| * and {@link #getKey()}. |
| */ |
| public interface Result<K,T extends Persistent> extends Closeable { |
| |
| /** |
| * Returns the DataStore, that this Result is associated with. |
| * @return the DataStore of the Result |
| */ |
| DataStore<K,T> getDataStore(); |
| |
| /** |
| * Returns the Query object for this Result. |
| * @return the Query object for this Result. |
| */ |
| Query<K, T> getQuery(); |
| |
| /** |
| * Advances to the next element and returns false if at end. |
| * @return true if end is not reached yet |
| */ |
| boolean next() throws IOException; |
| |
| /** |
| * Returns the current key. |
| * @return current key |
| */ |
| K getKey(); |
| |
| /** |
| * Returns the current object. |
| * @return current object |
| */ |
| T get(); |
| |
| /** |
| * Returns the class of the keys |
| * @return class of the keys |
| */ |
| Class<K> getKeyClass(); |
| |
| /** |
| * Returns the class of the persistent objects |
| * @return class of the persistent objects |
| */ |
| Class<T> getPersistentClass(); |
| |
| /** |
| * Returns the number of times next() is called with return value true. |
| * @return the number of results so far |
| */ |
| long getOffset(); |
| |
| /** |
| * Returns how far along the result has iterated, a value between 0 and 1. |
| */ |
| float getProgress() throws IOException; |
| |
| @Override |
| void close() throws IOException; |
| |
| } |