src/main/java/nl/altindag/log/LogCaptor.java
/*
* Copyright 2019-2021 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
*
* https://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 nl.altindag.log;
import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.Appender;
import ch.qos.logback.core.filter.Filter;
import nl.altindag.log.appender.InMemoryAppender;
import nl.altindag.log.model.LogEvent;
import nl.altindag.log.util.JavaUtilLoggingLoggerUtils;
import nl.altindag.log.util.Mappers;
import nl.altindag.log.util.ValidationUtils;
import org.slf4j.LoggerFactory;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import static org.slf4j.Logger.ROOT_LOGGER_NAME;
/**
* @author Hakan Altindag
*/
public final class LogCaptor implements AutoCloseable {
private static final Map<String, Level> LOG_LEVEL_CONTAINER = new HashMap<>();
private static final List<String> CONSOLE_APPENDER_NAMES = Arrays.asList("console", "CONSOLE");
private final Logger logger;
private final Appender<ILoggingEvent> appender;
private final List<ILoggingEvent> eventsCollector = new CopyOnWriteArrayList<>();
private LogCaptor(String loggerName) {
org.slf4j.Logger slf4jLogger = LoggerFactory.getLogger(loggerName);
ValidationUtils.requireLoggerOfType(slf4jLogger, ch.qos.logback.classic.Logger.class);
logger = (Logger) slf4jLogger;
appender = new InMemoryAppender<>("log-captor", eventsCollector);
appender.start();
logger.addAppender(appender);
JavaUtilLoggingLoggerUtils.redirectToSlf4j(loggerName);
LOG_LEVEL_CONTAINER.putIfAbsent(logger.getName(), logger.getEffectiveLevel());
}
/**
* Captures all log messages
*
* @return LogCaptor instance for the root logger
*/
public static LogCaptor forRoot() {
return new LogCaptor(ROOT_LOGGER_NAME);
}
/**
* Captures log messages for the provided class
*
* @param clazz Class for capturing
* @return LogCaptor instance for the provided class
*/
public static LogCaptor forClass(Class<?> clazz) {
return new LogCaptor(clazz.getName());
}
/**
* Captures log messages for the provided logger name
*
* @param name Logger name for capturing
* @return LogCaptor instance for the provided logger name
*/
public static LogCaptor forName(String name) {
return new LogCaptor(name);
}
public List<String> getLogs() {
return getLogs(logEvent -> true, ILoggingEvent::getFormattedMessage);
}
public List<String> getInfoLogs() {
return getLogs(Level.INFO);
}
public List<String> getDebugLogs() {
return getLogs(Level.DEBUG);
}
public List<String> getWarnLogs() {
return getLogs(Level.WARN);
}
public List<String> getErrorLogs() {
return getLogs(Level.ERROR);
}
public List<String> getTraceLogs() {
return getLogs(Level.TRACE);
}
private List<String> getLogs(Level level) {
return getLogs(logEvent -> logEvent.getLevel() == level, ILoggingEvent::getFormattedMessage);
}
public List<LogEvent> getLogEvents() {
return getLogs(logEvent -> true, Mappers.toLogEvent());
}
private <T> List<T> getLogs(Predicate<ILoggingEvent> logEventPredicate, Function<ILoggingEvent, T> logEventMapper) {
synchronized (eventsCollector) {
return eventsCollector.stream()
.filter(logEventPredicate)
.map(logEventMapper)
.collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
}
}
public void addFilter(Filter<ILoggingEvent> filter) {
appender.addFilter(filter);
filter.start();
}
/**
* Overrides the log level property of the target logger. This may result that the overridden property
* of the target logger is still active even though a new instance of {@link LogCaptor} has been created.
* To roll-back to the initial state use: {@link LogCaptor#resetLogLevel()}
*
* This option will implicitly include the following log levels: WARN and ERROR
*/
public void setLogLevelToInfo() {
logger.setLevel(Level.INFO);
}
/**
* Overrides the log level property of the target logger. This may result that the overridden property
* of the target logger is still active even though a new instance of {@link LogCaptor} has been created.
* To roll-back to the initial state use: {@link LogCaptor#resetLogLevel()}
*
* This option will implicitly include the following log levels: INFO, WARN and ERROR
*/
public void setLogLevelToDebug() {
logger.setLevel(Level.DEBUG);
}
/**
* Overrides the log level property of the target logger. This may result that the overridden property
* of the target logger is still active even though a new instance of {@link LogCaptor} has been created.
* To roll-back to the initial state use: {@link LogCaptor#resetLogLevel()}
*
* This option will implicitly include the following log levels: INFO, DEBUG, WARN and ERROR
*/
public void setLogLevelToTrace() {
logger.setLevel(Level.TRACE);
}
/**
* Overrides the log level property of the target logger. This may result that the overridden property
* of the target logger is still active even though a new instance of {@link LogCaptor} has been created.
* To roll-back to the initial state use: {@link LogCaptor#resetLogLevel()}
*/
public void disableLogs() {
logger.setLevel(Level.OFF);
}
/**
* Disables the output of the log entries to the console. To revert this option use {@link LogCaptor#enableConsoleOutput()}.
* LogCaptor will still be capturing the log entries.
*/
public void disableConsoleOutput() {
getConsoleAppender().ifPresent(Appender::stop);
}
/**
* The output of the log entries to the console are enabled by default but can be re-enabled if
* they are disabled earlier by {@link LogCaptor#disableConsoleOutput()}
*/
public void enableConsoleOutput() {
getConsoleAppender().ifPresent(Appender::start);
}
Optional<Appender<ILoggingEvent>> getConsoleAppender() {
Logger rootLogger = logger.getLoggerContext()
.getLogger(ROOT_LOGGER_NAME);
return CONSOLE_APPENDER_NAMES.stream()
.map(rootLogger::getAppender)
.filter(Objects::nonNull)
.findFirst();
}
/**
* Resets the log level of the target logger to the initial value which was available before
* changing it with {@link LogCaptor#setLogLevelToInfo()}, {@link LogCaptor#setLogLevelToDebug()} or with {@link LogCaptor#setLogLevelToTrace()}
*/
public void resetLogLevel() {
Optional.ofNullable(LOG_LEVEL_CONTAINER.get(logger.getName()))
.ifPresent(logger::setLevel);
}
public void clearLogs() {
eventsCollector.clear();
}
@Override
public void close() {
logger.detachAppender(appender);
appender.stop();
}
}