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 * 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.
32 */
33 public interface Filter {
34
35 /**
36 * The result that can returned from a filter method call.
37 */
38 public enum Result {
39 /**
40 * The event will be processed without further filtering based on the log Level.
41 */
42 ACCEPT,
43 /**
44 * No decision could be made, further filtering should occur.
45 */
46 NEUTRAL,
47 /**
48 * The event should not be processed.
49 */
50 DENY;
51
52 /**
53 * Returns the Result for the given string.
54 *
55 * @param name The Result enum name, case-insensitive. If null, returns, null
56 * @return a Result enum value or null if name is null
57 */
58 public static Result toResult(final String name) {
59 return toResult(name, null);
60 }
61
62 /**
63 * Returns the Result for the given string.
64 *
65 * @param name The Result enum name, case-insensitive. If null, returns, defaultResult
66 * @param defaultResult the Result to return if name is null
67 * @return a Result enum value or null if name is null
68 */
69 public static Result toResult(final String name, final Result defaultResult) {
70 return EnglishEnums.valueOf(Result.class, name, defaultResult);
71 }
72 }
73
74 /**
75 * Returns the result that should be returned when the filter does not match the event.
76 * @return the Result that should be returned when the filter does not match the event.
77 */
78 Result getOnMismatch();
79 /**
80 * Returns the result that should be returned when the filter matches the event.
81 * @return the Result that should be returned when the filter matches the event.
82 */
83 Result getOnMatch();
84
85 /**
86 * Filter an event.
87 * @param logger The Logger.
88 * @param level The event logging Level.
89 * @param marker The Marker for the event or null.
90 * @param msg String text to filter on.
91 * @param params An array of parameters or null.
92 * @return the Result.
93 */
94 Result filter(Logger logger, Level level, Marker marker, String msg, Object... params);
95
96 /**
97 * Filter an event.
98 * @param logger The Logger.
99 * @param level The event logging Level.
100 * @param marker The Marker for the event or null.
101 * @param msg Any Object.
102 * @param t A Throwable or null.
103 * @return the Result.
104 */
105 Result filter(Logger logger, Level level, Marker marker, Object msg, Throwable t);
106
107 /**
108 * Filter an event.
109 * @param logger The Logger.
110 * @param level The event logging Level.
111 * @param marker The Marker for the event or null.
112 * @param msg The Message
113 * @param t A Throwable or null.
114 * @return the Result.
115 */
116 Result filter(Logger logger, Level level, Marker marker, Message msg, Throwable t);
117
118 /**
119 * Filter an event.
120 * @param event The Event to filter on.
121 * @return the Result.
122 */
123 Result filter(LogEvent event);
124
125 }