/* * Copyright 2002-2018 the original author or authors. * * Licensed 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.springframework.core.log; import java.util.function.Function; import org.apache.commons.logging.Log; import org.springframework.lang.Nullable; /** * Utility methods for formatting and logging messages. * * <p>Mainly for internal use within the framework with Apache Commons Logging, * typically in the form of the {@code spring-jcl} bridge but also compatible * with other Commons Logging bridges. * * @author Rossen Stoyanchev * @author Juergen Hoeller * @since 5.1 */ public abstract class LogFormatUtils { /** * Format the given value via {@code toString()}, quoting it if it is a * {@link CharSequence}, and possibly truncating at 100 if limitLength is * set to true. * @param value the value to format * @param limitLength whether to truncate large formatted values (over 100) * @return the formatted value */ public static String formatValue(@Nullable Object value, boolean limitLength) { if (value == null) { return ""; } String str; if (value instanceof CharSequence) { str = "\"" + value + "\""; } else { try { str = value.toString(); } catch (Throwable ex) { str = ex.toString(); } } return (limitLength && str.length() > 100 ? str.substring(0, 100) + " (truncated)..." : str); } /** * Use this to log a message with different levels of detail (or different * messages) at TRACE vs DEBUG log levels. Effectively, a substitute for: * <pre class="code"> * if (logger.isDebugEnabled()) { * String str = logger.isTraceEnabled() ? "..." : "..."; * if (logger.isTraceEnabled()) { * logger.trace(str); * } * else { * logger.debug(str); * } * } * </pre> * @param logger the logger to use to log the message * @param messageFactory function that accepts a boolean set to the value * of {@link Log#isTraceEnabled()} */ public static void traceDebug(Log logger, Function<Boolean, String> messageFactory) { if (logger.isDebugEnabled()) { String logMessage = messageFactory.apply(logger.isTraceEnabled()); if (logger.isTraceEnabled()) { logger.trace(logMessage); } else { logger.debug(logMessage); } } } }