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.config.plugins;
018
019import java.lang.annotation.Documented;
020import java.lang.annotation.ElementType;
021import java.lang.annotation.Retention;
022import java.lang.annotation.RetentionPolicy;
023import java.lang.annotation.Target;
024
025import org.apache.logging.log4j.core.config.plugins.visitors.PluginAttributeVisitor;
026import org.apache.logging.log4j.util.Strings;
027
028/**
029 * Identifies a Plugin Attribute and its default value. Note that only one of the defaultFoo attributes will be
030 * used based on the type this annotation is attached to. Thus, for primitive types, the default<i>Type</i>
031 * attribute will be used for some <i>Type</i>. However, for more complex types (including enums), the default
032 * string value is used instead and should correspond to the string that would correctly convert to the appropriate
033 * enum value using {@link Enum#valueOf(Class, String) Enum.valueOf}.
034 */
035@Documented
036@Retention(RetentionPolicy.RUNTIME)
037@Target({ElementType.PARAMETER, ElementType.FIELD})
038@PluginVisitorStrategy(PluginAttributeVisitor.class)
039public @interface PluginAttribute {
040
041    /**
042     * Specifies the default boolean value to use.
043     */
044    boolean defaultBoolean() default false;
045
046    /**
047     * Specifies the default byte value to use.
048     */
049    byte defaultByte() default 0;
050
051    /**
052     * Specifies the default byte value to use.
053     */
054    char defaultChar() default 0;
055
056    /**
057     * Specifies the default {@link Class} value to use.
058     */
059    Class<?> defaultClass() default Object.class;
060
061    /**
062     * Specifies the default double floating point value to use.
063     */
064    double defaultDouble() default 0.0d;
065
066    /**
067     * Specifies the default floating point value to use.
068     */
069    float defaultFloat() default 0.0f;
070
071    /**
072     * Specifies the default integer value to use.
073     */
074    int defaultInt() default 0;
075
076    /**
077     * Specifies the default long value to use.
078     */
079    long defaultLong() default 0L;
080
081    /**
082     * Specifies the default long value to use.
083     */
084    short defaultShort() default 0;
085
086    /**
087     * Specifies the default value this attribute should use if none is provided or if the provided value is invalid.
088     */
089    String defaultString() default Strings.EMPTY;
090
091    // TODO: could we allow a blank value and infer the attribute name through reflection?
092    /**
093     * Specifies the name of the attribute (case-insensitive) this annotation corresponds to.
094     */
095    String value();
096
097    /**
098     * Indicates that this attribute is a sensitive one that shouldn't be logged directly. Such attributes will instead
099     * be output as a hashed value.
100     */
101    boolean sensitive() default false;
102
103}