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.util;
018
019import java.util.Map;
020
021/**
022 * PropertySource backed by the current system properties. Other than having a higher priority over normal properties,
023 * this follows the same rules as {@link PropertiesPropertySource}.
024 *
025 * @since 2.10.0
026 */
027public class SystemPropertiesPropertySource implements PropertySource {
028
029    private static final String PREFIX = "log4j2.";
030
031    @Override
032    public int getPriority() {
033        return 100;
034    }
035
036    @Override
037    public void forEach(final BiConsumer<String, String> action) {
038        for (final Map.Entry<Object, Object> entry : System.getProperties().entrySet()) {
039            action.accept(((String) entry.getKey()), ((String) entry.getValue()));
040        }
041    }
042
043    @Override
044    public CharSequence getNormalForm(final Iterable<? extends CharSequence> tokens) {
045        return PREFIX + Util.joinAsCamelCase(tokens);
046    }
047
048}