| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache license, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the license for the specific language governing permissions and |
| * limitations under the license. |
| */ |
| package org.apache.logging.log4j.util; |
| |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * A source for global configuration properties. |
| * |
| * @since 2.10.0 |
| */ |
| public interface PropertySource { |
| |
| /** |
| * Returns the order in which this PropertySource has priority. A higher value means that the source will be |
| * applied later so as to take precedence over other property sources. |
| * |
| * @return priority value |
| */ |
| int getPriority(); |
| |
| /** |
| * Iterates over all properties and performs an action for each key/value pair. |
| * |
| * @param action action to perform on each key/value pair |
| */ |
| default void forEach(BiConsumer<String, String> action) { |
| } |
| |
| /** |
| * Converts a list of property name tokens into a normal form. For example, a list of tokens such as |
| * "foo", "bar", "baz", might be normalized into the property name "log4j2.fooBarBaz". |
| * |
| * @param tokens list of property name tokens |
| * @return a normalized property name using the given tokens |
| */ |
| default CharSequence getNormalForm(Iterable<? extends CharSequence> tokens) { |
| return null; |
| } |
| |
| /** |
| * For PropertySources that cannot iterate over all the potential properties this provides a direct lookup. |
| * @param key The key to search for. |
| * @return The value or null; |
| * @since 2.13.0 |
| */ |
| default String getProperty(String key) { |
| return null; |
| } |
| |
| |
| /** |
| * For PropertySources that cannot iterate over all the potential properties this provides a direct lookup. |
| * @param key The key to search for. |
| * @return The value or null; |
| * @since 2.13.0 |
| */ |
| default boolean containsProperty(String key) { |
| return false; |
| } |
| |
| /** |
| * Comparator for ordering PropertySource instances by priority. |
| * |
| * @since 2.10.0 |
| */ |
| class Comparator implements java.util.Comparator<PropertySource>, Serializable { |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public int compare(final PropertySource o1, final PropertySource o2) { |
| return Integer.compare(Objects.requireNonNull(o1).getPriority(), Objects.requireNonNull(o2).getPriority()); |
| } |
| } |
| |
| /** |
| * Utility methods useful for PropertySource implementations. |
| * |
| * @since 2.10.0 |
| */ |
| final class Util { |
| private static final String PREFIXES = "(?i:^log4j2?[-._/]?|^org\\.apache\\.logging\\.log4j\\.)?"; |
| private static final Pattern PROPERTY_TOKENIZER = Pattern.compile(PREFIXES + "([A-Z]*[a-z0-9]+|[A-Z0-9]+)[-._/]?"); |
| private static final Map<CharSequence, List<CharSequence>> CACHE = new ConcurrentHashMap<>(); |
| |
| /** |
| * Converts a property name string into a list of tokens. This will strip a prefix of {@code log4j}, |
| * {@code log4j2}, {@code Log4j}, or {@code org.apache.logging.log4j}, along with separators of |
| * dash {@code -}, dot {@code .}, underscore {@code _}, and slash {@code /}. Tokens can also be separated |
| * by camel case conventions without needing a separator character in between. |
| * |
| * @param value property name |
| * @return the property broken into lower case tokens |
| */ |
| public static List<CharSequence> tokenize(final CharSequence value) { |
| if (CACHE.containsKey(value)) { |
| return CACHE.get(value); |
| } |
| List<CharSequence> tokens = new ArrayList<>(); |
| final Matcher matcher = PROPERTY_TOKENIZER.matcher(value); |
| while (matcher.find()) { |
| tokens.add(matcher.group(1).toLowerCase()); |
| } |
| CACHE.put(value, tokens); |
| return tokens; |
| } |
| |
| /** |
| * Joins a list of strings using camelCaseConventions. |
| * |
| * @param tokens tokens to convert |
| * @return tokensAsCamelCase |
| */ |
| public static CharSequence joinAsCamelCase(final Iterable<? extends CharSequence> tokens) { |
| final StringBuilder sb = new StringBuilder(); |
| boolean first = true; |
| for (final CharSequence token : tokens) { |
| if (first) { |
| sb.append(token); |
| } else { |
| sb.append(Character.toUpperCase(token.charAt(0))); |
| if (token.length() > 1) { |
| sb.append(token.subSequence(1, token.length())); |
| } |
| } |
| first = false; |
| } |
| return sb.toString(); |
| } |
| |
| private Util() { |
| } |
| } |
| } |