DynamicThresholdFilter.java
/**
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2015, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package ch.qos.logback.classic.turbo;
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.Level;
import ch.qos.logback.core.spi.FilterReply;
import org.slf4j.Marker;
import org.slf4j.MDC;
import java.util.Map;
import java.util.HashMap;
/**
* This filter allows for efficient course grained filtering based on criteria
* such as product name or company name that would be associated with requests
* as they are processed.
*
* <p>
* This filter will allow you to associate threshold levels to a key put in the
* MDC. This key can be any value specified by the user. Furthermore, you can
* pass MDC value and level threshold associations, which are then looked up to
* find the level threshold to apply to the current logging request. If no level
* threshold could be found, then a 'default' value specified by the user is
* applied. We call this value 'levelAssociatedWithMDCValue'.
*
* <p>
* If 'levelAssociatedWithMDCValue' is higher or equal to the level of the
* current logger request, the
* {@link #decide(Marker, Logger, Level, String, Object[], Throwable) decide()}
* method returns the value of {@link #getOnHigherOrEqual() onHigherOrEqual}, if
* it is lower than the value of {@link #getOnLower() onLower} is returned. Both
* 'onHigherOrEqual' and 'onLower' can be set by the user. By default,
* 'onHigherOrEqual' is set to NEUTRAL and 'onLower' is set to DENY. Thus, if
* the current logger request's level is lower than
* 'levelAssociatedWithMDCValue', then the request is denied, and if it is
* higher or equal, then this filter decides NEUTRAL letting subsequent filters
* to make the decision on the fate of the logging request.
*
* <p>
* The example below illustrates how logging could be enabled for only
* individual users. In this example all events for logger names matching
* "com.mycompany" will be logged if they are for 'user1' and at a level higher
* than equals to DEBUG, and for 'user2' if they are at a level higher than or
* equal to TRACE, and for other users only if they are at level ERROR or
* higher. Events issued by loggers other than "com.mycompany" will only be
* logged if they are at level ERROR or higher since that is all the root logger
* allows.
*
* <pre>
* <configuration>
* <appender name="STDOUT"
* class="ch.qos.logback.core.ConsoleAppender">
* <layout class="ch.qos.logback.classic.PatternLayout">
* <Pattern>TEST %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</Pattern>
* </layout>
* </appender>
*
* <turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">
* <Key>userId</Key>
* <DefaultThreshold>ERROR</DefaultThreshold>
* <MDCValueLevelPair>
* <value>user1</value>
* <level>DEBUG</level>
* </MDCValueLevelPair>
* <MDCValueLevelPair>
* <value>user2</value>
* <level>TRACE</level>
* </MDCValueLevelPair>
* </turboFilter>
*
* <logger name="com.mycompany" level="TRACE"/>
*
* <root level="ERROR" >
* <appender-ref ref="STDOUT" />
* </root>
* </configuration>
* </pre>
*
* In the next configuration events from user1 and user2 will be logged
* regardless of the logger levels. Events for other users and records without a
* userid in the MDC will be logged if they are ERROR level messages. With this
* configuration, the root level is never checked since DynamicThresholdFilter
* will either accept or deny all records.
*
* <pre>
* <configuration>
* <appender name="STDOUT"
* class="ch.qos.logback.core.ConsoleAppender">
* <layout class="ch.qos.logback.classic.PatternLayout">
* <Pattern>TEST %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</Pattern>
* </layout>
* </appender>
*
* <turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">
* <Key>userId</Key>
* <DefaultThreshold>ERROR</DefaultThreshold>
* <OnHigherOrEqual>ACCEPT</OnHigherOrEqual>
* <OnLower>DENY</OnLower>
* <MDCValueLevelPair>
* <value>user1</value>
* <level>TRACE</level>
* </MDCValueLevelPair>
* <MDCValueLevelPair>
* <value>user2</value>
* <level>TRACE</level>
* </MDCValueLevelPair>
* </turboFilter>
*
* <root level="DEBUG" >
* <appender-ref ref="STDOUT" />
* </root>
* </configuration>
* </pre>
*
* @author Ralph Goers
* @author Ceki Gülcü
*/
public class DynamicThresholdFilter extends TurboFilter {
private Map<String, Level> valueLevelMap = new HashMap<String, Level>();
private Level defaultThreshold = Level.ERROR;
private String key;
private FilterReply onHigherOrEqual = FilterReply.NEUTRAL;
private FilterReply onLower = FilterReply.DENY;
/**
* Get the MDC key whose value will be used as a level threshold
*
* @return the name of the MDC key.
*/
public String getKey() {
return this.key;
}
/**
* @see setKey
*/
public void setKey(String key) {
this.key = key;
}
/**
* Get the default threshold value when the MDC key is not set.
*
* @return the default threshold value in the absence of a set MDC key
*/
public Level getDefaultThreshold() {
return defaultThreshold;
}
public void setDefaultThreshold(Level defaultThreshold) {
this.defaultThreshold = defaultThreshold;
}
/**
* Get the FilterReply when the effective level is higher or equal to the level
* of current logging request
*
* @return FilterReply
*/
public FilterReply getOnHigherOrEqual() {
return onHigherOrEqual;
}
public void setOnHigherOrEqual(FilterReply onHigherOrEqual) {
this.onHigherOrEqual = onHigherOrEqual;
}
/**
* Get the FilterReply when the effective level is lower than the level of
* current logging request
*
* @return FilterReply
*/
public FilterReply getOnLower() {
return onLower;
}
public void setOnLower(FilterReply onLower) {
this.onLower = onLower;
}
/**
* Add a new MDCValuePair
*/
public void addMDCValueLevelPair(MDCValueLevelPair mdcValueLevelPair) {
if (valueLevelMap.containsKey(mdcValueLevelPair.getValue())) {
addError(mdcValueLevelPair.getValue() + " has been already set");
} else {
valueLevelMap.put(mdcValueLevelPair.getValue(), mdcValueLevelPair.getLevel());
}
}
/**
*
*/
@Override
public void start() {
if (this.key == null) {
addError("No key name was specified");
}
super.start();
}
/**
* This method first finds the MDC value for 'key'. It then finds the level
* threshold associated with this MDC value from the list of MDCValueLevelPair
* passed to this filter. This value is stored in a variable called
* 'levelAssociatedWithMDCValue'. If it is null, then it is set to the
*
* @{link #defaultThreshold} value.
*
* If no such value exists, then
*
*
* @param marker
* @param logger
* @param level
* @param s
* @param objects
* @param throwable
*
* @return FilterReply - this filter's decision
*/
@Override
public FilterReply decide(Marker marker, Logger logger, Level level, String s, Object[] objects,
Throwable throwable) {
String mdcValue = MDC.get(this.key);
if (!isStarted()) {
return FilterReply.NEUTRAL;
}
Level levelAssociatedWithMDCValue = null;
if (mdcValue != null) {
levelAssociatedWithMDCValue = valueLevelMap.get(mdcValue);
}
if (levelAssociatedWithMDCValue == null) {
levelAssociatedWithMDCValue = defaultThreshold;
}
if (level.isGreaterOrEqual(levelAssociatedWithMDCValue)) {
return onHigherOrEqual;
} else {
return onLower;
}
}
}