Package com.nuix.logging

Class LogHelper

  • public class LogHelper
extends java.lang.Object
    Provides various convenience methods for log4j2 related tasks, since doing some operations programmatically in log4j2 are not very straightforward.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      org.apache.logging.log4j.core.appender.ConsoleAppender attachConsoleAppender​(java.lang.String pattern, java.util.function.Function<org.apache.logging.log4j.core.LogEvent,​java.lang.Boolean> filteringFunction)
      Attaches a ConsoleAppender
      org.apache.logging.log4j.core.appender.ConsoleAppender attachConsoleAppender​(java.lang.String pattern, org.apache.logging.log4j.core.Filter filter)
      Attaches a new ConsoleAppender
      void attachLogAppender​(@NonNull org.apache.logging.log4j.core.Appender appender)
      Attaches the given appender
      LogMessageCallbackAppender attachLogMessageCallbackAppender​(java.lang.String pattern, java.util.Collection<java.lang.String> regexPatterns, java.util.function.Consumer<java.lang.String> consumer)
      Attaches to logging system and returns a LogMessageCallbackAppender whose purpose is to forward rendered log event strings to a Consumer which then in turn makes use of that message.
      LogMessageCallbackAppender attachLogMessageCallbackAppender​(java.lang.String pattern, java.util.function.Consumer<java.lang.String> consumer)
      Attaches to logging system and returns a LogMessageCallbackAppender whose purpose is to forward rendered log event strings to a Consumer which then in turn makes use of that message.
      org.apache.logging.log4j.core.Filter createAcceptAllFilter()
      Creates a Filter which accepts all log events.
      org.apache.logging.log4j.core.Filter createPassFailFilter​(java.util.function.Function<org.apache.logging.log4j.core.LogEvent,​java.lang.Boolean> filteringFunction)
      Convenience method for converting a Function<LogEvent,Boolean> into a AbstractFilter which will yield ACCEPT when the function returns True and DENY when the function returns False.
      static LogHelper getInstance()  
      org.apache.logging.log4j.Logger getLogger()
      Convenience method for obtaining a logger object, named after the class calling this method.
      org.apache.logging.log4j.Logger getLogger​(java.lang.String name)
      Convenience method for obtaining a logger object.
      org.apache.logging.log4j.Level getRootLoggerLevel()
      Gets the current level of the root logger
      void initAlternateLogFile​(@NonNull java.io.File logFile, java.lang.String pattern, java.util.function.Function<org.apache.logging.log4j.core.LogEvent,​java.lang.Boolean> filteringFunction)
      Creates a file appender which will log to the specified file.
      org.apache.logging.log4j.core.appender.FileAppender initAlternateLogFile​(@NonNull java.io.File logFile, java.lang.String pattern, org.apache.logging.log4j.core.Filter filter)
      Creates a file appender which will log to the specified file.
      void removeAppender​(@NonNull org.apache.logging.log4j.core.Appender appender)
      Removes the given appender
      org.apache.logging.log4j.Level setRootLoggerLevel​(org.apache.logging.log4j.Level level)
      Sets the root logger's level, returning the level it was set to before changing it, in case you wish to later set it back to where it was.
      org.apache.logging.log4j.Level setRootLoggerLevelAll()  
      org.apache.logging.log4j.Level setRootLoggerLevelDebug()  
      org.apache.logging.log4j.Level setRootLoggerLevelError()  
      org.apache.logging.log4j.Level setRootLoggerLevelFatal()  
      org.apache.logging.log4j.Level setRootLoggerLevelInfo()  
      org.apache.logging.log4j.Level setRootLoggerLevelOff()  
      org.apache.logging.log4j.Level setRootLoggerLevelTrace()  
      org.apache.logging.log4j.Level setRootLoggerLevelWarn()  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • getInstance

        public static LogHelper getInstance()

      • getRootLoggerLevel

        public org.apache.logging.log4j.Level getRootLoggerLevel()
        Gets the current level of the root logger
        Returns:
        The root logger's current level

      • setRootLoggerLevel

        public org.apache.logging.log4j.Level setRootLoggerLevel​(org.apache.logging.log4j.Level level)
        Sets the root logger's level, returning the level it was set to before changing it, in case you wish to later set it back to where it was.
        Parameters:
        level - The new level to assign to the root logger
        Returns:
        The root logger's level before changing it

      • setRootLoggerLevelOff

        public org.apache.logging.log4j.Level setRootLoggerLevelOff()

      • setRootLoggerLevelFatal

        public org.apache.logging.log4j.Level setRootLoggerLevelFatal()

      • setRootLoggerLevelError

        public org.apache.logging.log4j.Level setRootLoggerLevelError()

      • setRootLoggerLevelWarn

        public org.apache.logging.log4j.Level setRootLoggerLevelWarn()

      • setRootLoggerLevelInfo

        public org.apache.logging.log4j.Level setRootLoggerLevelInfo()

      • setRootLoggerLevelDebug

        public org.apache.logging.log4j.Level setRootLoggerLevelDebug()

      • setRootLoggerLevelTrace

        public org.apache.logging.log4j.Level setRootLoggerLevelTrace()

      • setRootLoggerLevelAll

        public org.apache.logging.log4j.Level setRootLoggerLevelAll()

      • initAlternateLogFile

        public org.apache.logging.log4j.core.appender.FileAppender initAlternateLogFile​(@NonNull
                                                                                @NonNull java.io.File logFile,
                                                                                java.lang.String pattern,
                                                                                org.apache.logging.log4j.core.Filter filter)
        Creates a file appender which will log to the specified file. If a pattern is provided, it will be used as the layout (see docs). If no pattern is supplied, then a default of "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n" will be used. If a filter is provided, it will be used to determine which log events are ultimately written to the created file appender (and therefore the log file this creates). If no filter is provided, a default one will be used which accepts all log events it is provided.
        Parameters:
        logFile - The absolute file path to which this appender will write events
        pattern - The logging pattern, uses "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n" if null provided.
        filter - The filter used to determine which log events are written. Will accept all events if null is provided.
        Returns:
        The FileAppender object, which could be used to later remove/close the appender.

      • attachConsoleAppender

        public org.apache.logging.log4j.core.appender.ConsoleAppender attachConsoleAppender​(java.lang.String pattern,
                                                                                    org.apache.logging.log4j.core.Filter filter)
        Attaches a new ConsoleAppender
        Parameters:
        pattern - The pattern to use, a null value will default to %d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n
        filter - The filter to use, a null value will default to filter returned by createAcceptAllFilter().
        Returns:
        Returns the newly created and attached console appender

      • attachLogAppender

        public void attachLogAppender​(@NonNull
                              @NonNull org.apache.logging.log4j.core.Appender appender)
        Attaches the given appender
        Parameters:
        appender - The appender to attach

      • removeAppender

        public void removeAppender​(@NonNull
                           @NonNull org.apache.logging.log4j.core.Appender appender)
        Removes the given appender
        Parameters:
        appender - The appender to remove

      • attachConsoleAppender

        public org.apache.logging.log4j.core.appender.ConsoleAppender attachConsoleAppender​(java.lang.String pattern,
                                                                                    java.util.function.Function<org.apache.logging.log4j.core.LogEvent,​java.lang.Boolean> filteringFunction)
        Attaches a ConsoleAppender
        Parameters:
        pattern - The pattern to use
        filteringFunction - A function that will receive each log event, returning True to ACCEPT and False to DENY.
        Returns:
        The newly created console appender

      • initAlternateLogFile

        public void initAlternateLogFile​(@NonNull
                                 @NonNull java.io.File logFile,
                                 java.lang.String pattern,
                                 java.util.function.Function<org.apache.logging.log4j.core.LogEvent,​java.lang.Boolean> filteringFunction)
        Creates a file appender which will log to the specified file. If a pattern is provided, it will be used as the layout (see docs). If no pattern is supplied, then a default of "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n" will be used. If a filter is provided, it will be used to determine which log events are ultimately written to the created file appender (and therefore the log file this creates). If no filter is provided, a default one will be used which accepts all log events it is provided. This differs from the method initAlternateLogFile(File, String, Filter) in that this function accepts a generic Function<LogEvent,Boolean> which will be wrapped by an anonymous AbstractFilter instance. When the provided filtering function returns True, the wrapped filter will return an ACCEPT result. When it returns False, the wrapped will return a DENY result. This method exists mostly to make working with it from a scripting language (such as Ruby) potentially easier. Example in Ruby:
         
 LogHelper.initAlternateLogFile(java.io.File.new("D:\\temp\\script.log"),nil) do |event|
 	next (!event.nil? && event.getLoggerName.startsWith("proservTest"))
 end
        Parameters:
        logFile - The absolute file path to which this appender will write events
        pattern - The logging pattern, uses "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n" if null provided.
        filteringFunction - A function that will receive each log event, returning True to ACCEPT and False to DENY.

      • attachLogMessageCallbackAppender

        public LogMessageCallbackAppender attachLogMessageCallbackAppender​(java.lang.String pattern,
                                                                   java.util.function.Consumer<java.lang.String> consumer)
        Attaches to logging system and returns a LogMessageCallbackAppender whose purpose is to forward rendered log event strings to a Consumer which then in turn makes use of that message. For example, if you wish to forward log messages to the Nuix script console you might do something like: 
        
 pattern = "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n"
 appender = LogHelper.getInstance.attachLogMessageCallbackAppender(pattern){|message| puts message}
        Note that by default, no filtering is applied to log events! If you wish to control which log events get forwarded the you will want to instead do something like this: 
        
 pattern = "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n"
 appender = LogHelper.getInstance.attachLogMessageCallbackAppender(pattern){|message| puts message}
 filter = LogHelper.getInstance.createPassFailFilter do |log_event|
  return log_event.getLoggerName == "MY_SPECIAL_LOGGER"
 end
 appender.addFilter(filter)
        Parameters:
        pattern - The pattern used to construct the PatternLayout that will be used to render LogEvent instances into strings.
        consumer - The consumer which will receive log messages.
        Returns:
        The appender so you can remove it at a later time using removeAppender(Appender).

      • attachLogMessageCallbackAppender

        public LogMessageCallbackAppender attachLogMessageCallbackAppender​(java.lang.String pattern,
                                                                   java.util.Collection<java.lang.String> regexPatterns,
                                                                   java.util.function.Consumer<java.lang.String> consumer)
        Attaches to logging system and returns a LogMessageCallbackAppender whose purpose is to forward rendered log event strings to a Consumer which then in turn makes use of that message. This will also attach a Filter which will accept any LogEvents in which the logger name matches one of the provided regex patterns. For example, if you wish to forward log messages to the Nuix script console you might do something like: 
        
 pattern = "%d{yyyy-MM-dd HH:mm:ss.SSS Z} [%t] %r %-5p %c - %m%n"
 regex_patterns = ["com\.nuix\.proserv.*"] # Forward events from this library
 appender = LogHelper.getInstance.attachLogMessageCallbackAppender(pattern){|message| puts message}
        Parameters:
        pattern - The pattern used to construct the PatternLayout that will be used to render LogEvent instances into strings.
        regexPatterns - One or more regular expressions that will be used by the filter to filter log events by their logger name.
        consumer - The consumer which will receive log messages.
        Returns:
        The appender so you can remove it at a later time using removeAppender(Appender).

      • getLogger

        public org.apache.logging.log4j.Logger getLogger​(java.lang.String name)
        Convenience method for obtaining a logger object.
        Parameters:
        name - The name to assign the logger
        Returns:
        A logger object

      • getLogger

        public org.apache.logging.log4j.Logger getLogger()
        Convenience method for obtaining a logger object, named after the class calling this method. Internally the class name is determined and then used in call to getLogger(String).
        Returns:
        A logger object

      • createPassFailFilter

        public org.apache.logging.log4j.core.Filter createPassFailFilter​(java.util.function.Function<org.apache.logging.log4j.core.LogEvent,​java.lang.Boolean> filteringFunction)
        Convenience method for converting a Function<LogEvent,Boolean> into a AbstractFilter which will yield ACCEPT when the function returns True and DENY when the function returns False.
        Parameters:
        filteringFunction - A function which will be used to determine what events are filtered.
        Returns:
        A Filter instance

      • createAcceptAllFilter

        public org.apache.logging.log4j.core.Filter createAcceptAllFilter()
        Creates a Filter which accepts all log events.
        Returns:
        A Filter which accepts all log events blindly