com.github.kagkarlsson.scheduler.logging.ConfigurableLogger Maven / Gradle / Ivy

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/**
 * Copyright (C) Gustav Karlsson
 *
 * 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 com.github.kagkarlsson.scheduler.logging;

import org.slf4j.Logger;

public class ConfigurableLogger {

    private interface LogMethod {
        void log(String format, Object... arguments);
    }

    private static class NoOpLogger extends ConfigurableLogger {
        private NoOpLogger() {
            super(null, false);
        }

        @Override
        public void log(String format, Throwable cause, Object... arguments) { }
    }

    private final LogMethod logMethod;
    private final boolean logStackTrace;

    private static final ConfigurableLogger NO_OP_LOGGER = new NoOpLogger();

    private ConfigurableLogger(LogMethod logMethod, boolean logStackTrace) {
        this.logMethod = logMethod;
        this.logStackTrace = logStackTrace;
    }

    public static ConfigurableLogger create(Logger logger, LogLevel logLevel, boolean logStackTrace) {
        return logLevel == LogLevel.OFF ?
            NO_OP_LOGGER : new ConfigurableLogger(getLogMethod(logger, logLevel), logStackTrace);
    }

    public void log(String format, Throwable cause, Object... arguments) {
        if(logStackTrace) {
            // to log stack trace, throwable must be the very last parameter passed to the log method
            Object[] newArguments = new Object[arguments.length + 1];
            System.arraycopy(arguments, 0, newArguments, 0, arguments.length);
            newArguments[newArguments.length - 1] = cause;

            logMethod.log(format, newArguments);
        } else {
            logMethod.log(format, arguments);
        }
    }

    private static LogMethod getLogMethod(Logger logger, LogLevel logLevel) {
        LogMethod logMethod = logger::debug;

        switch (logLevel) {
            case TRACE:
                logMethod = logger::trace;
                break;
            case DEBUG:
                logMethod = logger::debug;
                break;
            case INFO:
                logMethod = logger::info;
                break;
            case WARN:
                logMethod = logger::warn;
                break;
            case ERROR:
                logMethod = logger::error;
                break;
        }

        return logMethod;
    }
}