001/*
002 * Copyright 2018-2018 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.boot.devtools.logger;
018
019import java.util.LinkedHashMap;
020import java.util.Map;
021
022import org.apache.commons.logging.Log;
023
024import org.springframework.boot.context.event.ApplicationPreparedEvent;
025import org.springframework.boot.logging.DeferredLog;
026import org.springframework.context.ApplicationListener;
027
028/**
029 * Devtools deferred logging support.
030 *
031 * @author Phillip Webb
032 * @since 2.1.0
033 */
034public final class DevToolsLogFactory {
035
036        private static final Map<Log, Class<?>> logs = new LinkedHashMap<>();
037
038        private DevToolsLogFactory() {
039        }
040
041        /**
042         * Get a {@link Log} instance for the specified source that will be automatically
043         * {@link DeferredLog#switchTo(Class) switched} when the
044         * {@link ApplicationPreparedEvent context is prepared}.
045         * @param source the source for logging
046         * @return a {@link DeferredLog} instance
047         */
048        public static Log getLog(Class<?> source) {
049                synchronized (logs) {
050                        Log log = new DeferredLog();
051                        logs.put(log, source);
052                        return log;
053                }
054        }
055
056        /**
057         * Listener used to log and switch when the context is ready.
058         */
059        static class Listener implements ApplicationListener<ApplicationPreparedEvent> {
060
061                @Override
062                public void onApplicationEvent(ApplicationPreparedEvent event) {
063                        synchronized (logs) {
064                                logs.forEach((log, source) -> {
065                                        if (log instanceof DeferredLog) {
066                                                ((DeferredLog) log).switchTo(source);
067                                        }
068                                });
069                                logs.clear();
070                        }
071                }
072
073        }
074
075}