001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017package org.apache.logging.log4j.core.appender.nosql; 018 019import java.io.Closeable; 020 021/** 022 * Represents a connection to the NoSQL database. Serves as a factory for new (empty) objects and an endpoint for 023 * inserted objects. 024 * 025 * @param <T> Specifies which implementation of {@link NoSqlObject} this connection provides. 026 * @param <W> Specifies which type of database object is wrapped by the {@link NoSqlObject} implementation provided. 027 */ 028public interface NoSqlConnection<W, T extends NoSqlObject<W>> extends Closeable { 029 /** 030 * Instantiates and returns a {@link NoSqlObject} instance whose properties can be configured before ultimate 031 * insertion via {@link #insertObject(NoSqlObject)}. 032 * 033 * @return a new object. 034 * @see NoSqlObject 035 */ 036 T createObject(); 037 038 /** 039 * Creates an array of the specified length typed to match the {@link NoSqlObject} implementation appropriate for 040 * this provider. 041 * 042 * @param length the length of the array to create. 043 * @return a new array. 044 * @see NoSqlObject 045 */ 046 T[] createList(int length); 047 048 /** 049 * Inserts the given object into the underlying NoSQL database. 050 * 051 * @param object The object to insert. 052 */ 053 void insertObject(NoSqlObject<W> object); 054 055 /** 056 * Closes the underlying connection. This method call should be idempotent. Only the first call should have any 057 * effect; all further calls should be ignored. It's possible the underlying connection is stateless (such as an 058 * HTTP web service), in which case this method would be a no-op. This method should also commit any open 059 * transactions, if applicable and if not already committed. 060 * <p> 061 * If this connection is part of a connection pool, executing this method should commit the transaction and return 062 * the connection to the pool, but it should not actually close the underlying connection. 063 * </p> 064 */ 065 @Override 066 void close(); 067 068 /** 069 * Indicates whether the underlying connection is closed. If the underlying connection is stateless (such as an 070 * HTTP web service), this method would likely always return true. Essentially, this method should only return 071 * {@code true} if a call to {@link #insertObject(NoSqlObject)} <b>will</b> fail due to the state of this object. 072 * 073 * @return {@code true} if this object is considered closed. 074 */ 075 boolean isClosed(); 076}