org.fujion.logging.LogUtil Maven / Gradle / Ivy
/*
* #%L
* fujion
* %%
* Copyright (C) 2018 Fujion Framework
* %%
* 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.
*
* #L%
*/
package org.fujion.logging;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
/**
* Convenience methods for initializing logging settings on the client. These are used during
* application startup. Changing these settings after application startup will only affect new
* sessions.
*
* Client logging settings are specified in an external property file. A logging {@link LogTarget
* target} can be specified for each logging {@link LogLevel level}. For example, the client can be
* configured to log {@link LogLevel#FATAL fatal} and {@link LogLevel#ERROR error} level messages at
* the server, {@link LogLevel#DEBUG debug} at both the client and the server, and all others only
* at the client.
*/
public class LogUtil {
/**
* Supported log levels.
*/
public enum LogLevel {
UNKNOWN, DEBUG, ERROR, FATAL, INFO, TRACE, WARN
}
/**
* Client logging targets.
*/
public enum LogTarget {
/**
* No logging should occur.
*/
NONE,
/**
* Logs on the client console only.
*/
CLIENT,
/**
* Logs using the server's logging framework.
*/
SERVER,
/**
* Logs on both client and server.
*/
BOTH;
}
private static Map settings = new HashMap<>();
private static volatile String clientSettings;
/**
* Initializes client logging settings. This is called during application startup to inject
* logging settings specified in an external property file.
*
* @param settings Map of logging settings.
*/
public static void initSettings(Map settings) {
for (Entry entry : settings.entrySet()) {
setTarget(toLevel(entry.getKey()), toTarget(entry.getValue()));
}
}
/**
* Returns the client logging target for the specified logging level.
*
* @param level The logging level.
* @return The client logging target.
*/
public static LogTarget getTarget(LogLevel level) {
LogTarget target = settings.get(level);
return target == null ? LogTarget.NONE : target;
}
/**
* Sets the client logging target for a given logging level.
*
* @param level The logging level.
* @param target The logging target.
* @return The previous logging target, if any.
*/
public static LogTarget setTarget(LogLevel level, LogTarget target) {
synchronized (settings) {
clientSettings = null;
if (target == null || target == LogTarget.NONE) {
return settings.remove(level);
}
return settings.put(level, target);
}
}
/**
* Returns a JSON string that will be used by the client to initialize logging settings.
*
* @return A JSON string that will be used by the client to initialize logging settings.
*/
public static String getSettingsForClient() {
return clientSettings == null ? initSettingsForClient() : clientSettings;
}
private static String initSettingsForClient() {
synchronized (settings) {
if (clientSettings == null) {
StringBuilder sb = new StringBuilder("{");
String delim = "";
for (Entry entry : settings.entrySet()) {
if (entry.getValue() != null && entry.getValue() != LogTarget.NONE) {
sb.append(delim).append(entry.getKey().name().toLowerCase()).append(":")
.append(entry.getValue().ordinal());
delim = ",";
}
}
clientSettings = sb.append("}").toString();
}
}
return clientSettings;
}
/**
* Returns the {@link LogLevel logging level} from its text equivalent.
*
* @param level Text to convert.
* @return The {@link LogLevel logging level}.
*/
public static LogLevel toLevel(String level) {
try {
return LogLevel.valueOf(level.toUpperCase());
} catch (Exception e) {
return LogLevel.UNKNOWN;
}
}
/**
* Returns the {@link LogTarget logging target} from its text equivalent.
*
* @param target Text to convert.
* @return The {@link LogTarget logging target}.
*/
public static LogTarget toTarget(String target) {
try {
return LogTarget.valueOf(target.toUpperCase());
} catch (Exception e) {
return LogTarget.NONE;
}
}
private LogUtil() {
}
}