1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17 package org.apache.logging.log4j.core.appender.nosql;
18
19 import java.io.Closeable;
20
21 /**
22 * Represents a connection to the NoSQL database. Serves as a factory for new (empty) objects and an endpoint for
23 * inserted objects.
24 *
25 * @param <T> Specifies which implementation of {@link NoSqlObject} this connection provides.
26 * @param <W> Specifies which type of database object is wrapped by the {@link NoSqlObject} implementation provided.
27 */
28 public interface NoSqlConnection<W, T extends NoSqlObject<W>> extends Closeable {
29 /**
30 * Instantiates and returns a {@link NoSqlObject} instance whose properties can be configured before ultimate
31 * insertion via {@link #insertObject(NoSqlObject)}.
32 *
33 * @return a new object.
34 * @see NoSqlObject
35 */
36 T createObject();
37
38 /**
39 * Creates an array of the specified length typed to match the {@link NoSqlObject} implementation appropriate for
40 * this provider.
41 *
42 * @param length the length of the array to create.
43 * @return a new array.
44 * @see NoSqlObject
45 */
46 T[] createList(int length);
47
48 /**
49 * Inserts the given object into the underlying NoSQL database.
50 *
51 * @param object The object to insert.
52 */
53 void insertObject(NoSqlObject<W> object);
54
55 /**
56 * Closes the underlying connection. This method call should be idempotent. Only the first call should have any
57 * effect; all further calls should be ignored. It's possible the underlying connection is stateless (such as an
58 * HTTP web service), in which case this method would be a no-op. This method should also commit any open
59 * transactions, if applicable and if not already committed.
60 * <p>
61 * If this connection is part of a connection pool, executing this method should commit the transaction and return
62 * the connection to the pool, but it should not actually close the underlying connection.
63 * </p>
64 */
65 @Override
66 void close();
67
68 /**
69 * Indicates whether the underlying connection is closed. If the underlying connection is stateless (such as an
70 * HTTP web service), this method would likely always return true. Essentially, this method should only return
71 * {@code true} if a call to {@link #insertObject(NoSqlObject)} <b>will</b> fail due to the state of this object.
72 *
73 * @return {@code true} if this object is considered closed.
74 */
75 boolean isClosed();
76 }