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
18 package org.apache.logging.log4j.core;
19
20 import org.apache.logging.log4j.Level;
21 import org.apache.logging.log4j.Marker;
22 import org.apache.logging.log4j.message.Message;
23 import org.apache.logging.log4j.util.EnglishEnums;
24
25 /**
26 * Interface that must be implemented to allow custom event filtering. It is highly recommended that
27 * applications make use of the Filters provided with this implementation before creating their own.
28 *
29 * <p>This interface supports "global" filters (i.e. - all events must pass through them first), attached to
30 * specific loggers and associated with Appenders. It is recommended that, where possible, Filter implementations
31 * create a generic filtering method that can be called from any of the filter methods.</p>
32 */
33 public interface Filter extends LifeCycle {
34
35 /**
36 * Main {@linkplain org.apache.logging.log4j.core.config.plugins.Plugin#elementType() plugin element type} for
37 * Filter plugins.
38 *
39 * @since 2.1
40 */
41 String ELEMENT_TYPE = "filter";
42
43 /**
44 * The result that can returned from a filter method call.
45 */
46 enum Result {
47 /**
48 * The event will be processed without further filtering based on the log Level.
49 */
50 ACCEPT,
51 /**
52 * No decision could be made, further filtering should occur.
53 */
54 NEUTRAL,
55 /**
56 * The event should not be processed.
57 */
58 DENY;
59
60 /**
61 * Returns the Result for the given string.
62 *
63 * @param name The Result enum name, case-insensitive. If null, returns, null
64 * @return a Result enum value or null if name is null
65 */
66 public static Result toResult(final String name) {
67 return toResult(name, null);
68 }
69
70 /**
71 * Returns the Result for the given string.
72 *
73 * @param name The Result enum name, case-insensitive. If null, returns, defaultResult
74 * @param defaultResult the Result to return if name is null
75 * @return a Result enum value or null if name is null
76 */
77 public static Result toResult(final String name, final Result defaultResult) {
78 return EnglishEnums.valueOf(Result.class, name, defaultResult);
79 }
80 }
81
82 /**
83 * Returns the result that should be returned when the filter does not match the event.
84 * @return the Result that should be returned when the filter does not match the event.
85 */
86 Result getOnMismatch();
87 /**
88 * Returns the result that should be returned when the filter matches the event.
89 * @return the Result that should be returned when the filter matches the event.
90 */
91 Result getOnMatch();
92
93 /**
94 * Filter an event.
95 * @param logger The Logger.
96 * @param level The event logging Level.
97 * @param marker The Marker for the event or null.
98 * @param msg String text to filter on.
99 * @param params An array of parameters or null.
100 * @return the Result.
101 */
102 Result filter(Logger logger, Level level, Marker marker, String msg, Object... params);
103
104 /**
105 * Filter an event.
106 * @param logger The Logger.
107 * @param level The event logging Level.
108 * @param marker The Marker for the event or null.
109 * @param msg Any Object.
110 * @param t A Throwable or null.
111 * @return the Result.
112 */
113 Result filter(Logger logger, Level level, Marker marker, Object msg, Throwable t);
114
115 /**
116 * Filter an event.
117 * @param logger The Logger.
118 * @param level The event logging Level.
119 * @param marker The Marker for the event or null.
120 * @param msg The Message
121 * @param t A Throwable or null.
122 * @return the Result.
123 */
124 Result filter(Logger logger, Level level, Marker marker, Message msg, Throwable t);
125
126 /**
127 * Filter an event.
128 * @param event The Event to filter on.
129 * @return the Result.
130 */
131 Result filter(LogEvent event);
132
133 }