Package org.apache.log4j.receivers.varia

Class LogFilePatternReceiver

  • All Implemented Interfaces:
    Plugin, Component, Thresholdable, org.apache.log4j.spi.OptionHandler
    public class LogFilePatternReceiver
extends Receiver
    LogFilePatternReceiver can parse and tail log files, converting entries into LoggingEvents. If the file doesn't exist when the receiver is initialized, the receiver will look for the file once every 10 seconds.

    This receiver relies on java.util.regex features to perform the parsing of text in the log file, however the only regular expression field explicitly supported is a glob-style wildcard used to ignore fields in the log file if needed. All other fields are parsed by using the supplied keywords.

    Features:
    - specify the URL of the log file to be processed
    - specify the timestamp format in the file (if one exists, using patterns from SimpleDateFormat)
    - specify the pattern (logFormat) used in the log file using keywords, a wildcard character (*) and fixed text
    - 'tail' the file (allows the contents of the file to be continually read and new events processed)
    - supports the parsing of multi-line messages and exceptions - 'hostname' property set to URL host (or 'file' if not available) - 'application' property set to URL path (or value of fileURL if not available)

    Keywords:
    TIMESTAMP
    LOGGER
    LEVEL
    THREAD
    CLASS
    FILE
    LINE
    METHOD
    RELATIVETIME
    MESSAGE
    NDC
    PROP(key)

    Use a * to ignore portions of the log format that should be ignored

    Example:
    If your file's patternlayout is this:
    %d %-5p [%t] %C{2} (%F:%L) - %m%n

    specify this as the log format:
    TIMESTAMP LEVEL [THREAD] CLASS (FILE:LINE) - MESSAGE

    To define a PROPERTY field, use PROP(key)

    Example:
    If you used the RELATIVETIME pattern layout character in the file, you can use PROP(RELATIVETIME) in the logFormat definition to assign the RELATIVETIME field as a property on the event.

    If your file's patternlayout is this:
    %r [%t] %-5p %c %x - %m%n

    specify this as the log format:
    PROP(RELATIVETIME) [THREAD] LEVEL LOGGER * - MESSAGE

    Note the * - it can be used to ignore a single word or sequence of words in the log file (in order for the wildcard to ignore a sequence of words, the text being ignored must be followed by some delimiter, like '-' or '[') - ndc is being ignored in the following example.

    Assign a filterExpression in order to only process events which match a filter. If a filterExpression is not assigned, all events are processed.

    Limitations:
    - no support for the single-line version of throwable supported by patternlayout
    (this version of throwable will be included as the last line of the message)
    - the relativetime patternLayout character must be set as a property: PROP(RELATIVETIME)
    - messages should appear as the last field of the logFormat because the variability in message content
    - exceptions are converted if the exception stack trace (other than the first line of the exception)
    is stored in the log file with a tab followed by the word 'at' as the first characters in the line
    - tailing may fail if the file rolls over.

    Example receiver configuration settings (add these as params, specifying a LogFilePatternReceiver 'plugin'):
    param: "timestampFormat" value="yyyy-MM-d HH:mm:ss,SSS"
    param: "logFormat" value="PROP(RELATIVETIME) [THREAD] LEVEL LOGGER * - MESSAGE"
    param: "fileURL" value="file:///c:/events.log"
    param: "tailing" value="true"

    This configuration will be able to process these sample events:
    710 [ Thread-0] DEBUG first.logger first - something here something else
    880 [ Thread-2] DEBUG first.logger third - something here something else
    880 [ Thread-0] INFO first.logger first - infomsg-0
    java.lang.Exception: someexception-first
    at Generator2.run(Generator2.java:102)

    • Field Detail

      • keywords

        private final java.util.List keywords

      • EXCEPTION_PATTERN

        private static final java.lang.String EXCEPTION_PATTERN
        See Also:
        Constant Field Values

      • REGEXP_DEFAULT_WILDCARD

        private static final java.lang.String REGEXP_DEFAULT_WILDCARD
        See Also:
        Constant Field Values

      • REGEXP_GREEDY_WILDCARD

        private static final java.lang.String REGEXP_GREEDY_WILDCARD
        See Also:
        Constant Field Values

      • PATTERN_WILDCARD

        private static final java.lang.String PATTERN_WILDCARD
        See Also:
        Constant Field Values

      • MULTIPLE_SPACES_REGEXP

        private static final java.lang.String MULTIPLE_SPACES_REGEXP
        See Also:
        Constant Field Values

      • newLine

        private final java.lang.String newLine

      • emptyException

        private final java.lang.String[] emptyException

      • dateFormat

        private java.text.SimpleDateFormat dateFormat

      • timestampFormat

        private java.lang.String timestampFormat

      • logFormat

        private java.lang.String logFormat

      • customLevelDefinitions

        private java.lang.String customLevelDefinitions

      • fileURL

        private java.lang.String fileURL

      • host

        private java.lang.String host

      • path

        private java.lang.String path

      • tailing

        private boolean tailing

      • filterExpression

        private java.lang.String filterExpression

      • waitMillis

        private long waitMillis

      • VALID_DATEFORMAT_CHARS

        private static final java.lang.String VALID_DATEFORMAT_CHARS
        See Also:
        Constant Field Values

      • VALID_DATEFORMAT_CHAR_PATTERN

        private static final java.lang.String VALID_DATEFORMAT_CHAR_PATTERN
        See Also:
        Constant Field Values

      • expressionRule

        private Rule expressionRule

      • currentMap

        private java.util.Map currentMap

      • additionalLines

        private java.util.List additionalLines

      • matchingKeywords

        private java.util.List matchingKeywords

      • regexp

        private java.lang.String regexp

      • reader

        private java.io.Reader reader

      • regexpPattern

        private java.util.regex.Pattern regexpPattern

      • exceptionPattern

        private java.util.regex.Pattern exceptionPattern

      • timestampPatternText

        private java.lang.String timestampPatternText

      • useCurrentThread

        private boolean useCurrentThread

      • MISSING_FILE_RETRY_MILLIS

        public static final int MISSING_FILE_RETRY_MILLIS
        See Also:
        Constant Field Values

      • appendNonMatches

        private boolean appendNonMatches

      • customLevelDefinitionMap

        private final java.util.Map customLevelDefinitionMap

    • Constructor Detail

      • LogFilePatternReceiver

        public LogFilePatternReceiver()

    • Method Detail

      • getFileURL

        public java.lang.String getFileURL()
        Accessor
        Returns:
        file URL

      • setFileURL

        public void setFileURL​(java.lang.String fileURL)
        Mutator
        Parameters:
        fileURL -

      • setCustomLevelDefinitions

        public void setCustomLevelDefinitions​(java.lang.String customLevelDefinitions)
        If the log file contains non-log4j level strings, they can be mapped to log4j levels using the format (android example): V=TRACE,D=DEBUG,I=INFO,W=WARN,E=ERROR,F=FATAL,S=OFF
        Parameters:
        customLevelDefinitions - the level definition string

      • getCustomLevelDefinitions

        public java.lang.String getCustomLevelDefinitions()

      • isAppendNonMatches

        public boolean isAppendNonMatches()
        Accessor
        Returns:
        append non matches

      • setAppendNonMatches

        public void setAppendNonMatches​(boolean appendNonMatches)
        Mutator
        Parameters:
        appendNonMatches -

      • getFilterExpression

        public java.lang.String getFilterExpression()
        Accessor
        Returns:
        filter expression

      • setFilterExpression

        public void setFilterExpression​(java.lang.String filterExpression)
        Mutator
        Parameters:
        filterExpression -

      • isTailing

        public boolean isTailing()
        Accessor
        Returns:
        tailing

      • setTailing

        public void setTailing​(boolean tailing)
        Mutator
        Parameters:
        tailing -

      • isUseCurrentThread

        public final boolean isUseCurrentThread()
        When true, this property uses the current Thread to perform the import, otherwise when false (the default), a new Thread is created and started to manage the import.
        Returns:
        true, if the current thread is used

      • setUseCurrentThread

        public final void setUseCurrentThread​(boolean useCurrentThread)
        Sets whether the current Thread or a new Thread is created to perform the import, the default being false (new Thread created).
        Parameters:
        useCurrentThread -

      • getLogFormat

        public java.lang.String getLogFormat()
        Accessor
        Returns:
        log format

      • setLogFormat

        public void setLogFormat​(java.lang.String logFormat)
        Mutator
        Parameters:
        logFormat - the format

      • setTimestampFormat

        public void setTimestampFormat​(java.lang.String timestampFormat)
        Mutator. Specify a pattern from SimpleDateFormat
        Parameters:
        timestampFormat -

      • getTimestampFormat

        public java.lang.String getTimestampFormat()
        Accessor
        Returns:
        timestamp format

      • getWaitMillis

        public long getWaitMillis()
        Accessor
        Returns:
        millis between retrieves of content

      • setWaitMillis

        public void setWaitMillis​(long waitMillis)
        Mutator
        Parameters:
        waitMillis -

      • getExceptionLine

        private int getExceptionLine()
        Walk the additionalLines list, looking for the EXCEPTION_PATTERN.

        Return the index of the first matched line (the match may be the 1st line of an exception)

        Assumptions:
        - the additionalLines list may contain both message and exception lines
        - message lines are added to the additionalLines list and then exception lines (all message lines occur in the list prior to all exception lines)

        Returns:
        -1 if no exception line exists, line number otherwise

      • buildMessage

        private java.lang.String buildMessage​(java.lang.String firstMessageLine,
                                      int exceptionLine)
        Combine all message lines occuring in the additionalLines list, adding a newline character between each line

        the event will already have a message - combine this message with the message lines in the additionalLines list (all entries prior to the exceptionLine index)

        Parameters:
        firstMessageLine - primary message line
        exceptionLine - index of first exception line
        Returns:
        message

      • buildException

        private java.lang.String[] buildException​(int exceptionLine)
        Combine all exception lines occuring in the additionalLines list into a String array

        (all entries equal to or greater than the exceptionLine index)

        Parameters:
        exceptionLine - index of first exception line
        Returns:
        exception

      • buildEvent

        private org.apache.log4j.spi.LoggingEvent buildEvent()
        Construct a logging event from currentMap and additionalLines (additionalLines contains multiple message lines and any exception lines)

        CurrentMap and additionalLines are cleared in the process

        Returns:
        event

      • process

        protected void process​(java.io.BufferedReader bufferedReader)
                throws java.io.IOException
        Read, parse and optionally tail the log file, converting entries into logging events. A runtimeException is thrown if the logFormat pattern is malformed.
        Parameters:
        bufferedReader -
        Throws:
        java.io.IOException

      • createPattern

        protected void createPattern()

      • passesExpression

        private boolean passesExpression​(org.apache.log4j.spi.LoggingEvent event)
        Helper method that supports the evaluation of the expression
        Parameters:
        event -
        Returns:
        true if expression isn't set, or the result of the evaluation otherwise

      • processEvent

        private java.util.Map processEvent​(java.util.regex.MatchResult result)
        Convert the match into a map.

        Relies on the fact that the matchingKeywords list is in the same order as the groups in the regular expression

        Parameters:
        result -
        Returns:
        map

      • convertTimestamp

        private java.lang.String convertTimestamp()
        Helper method that will convert timestamp format to a pattern
        Returns:
        string

      • setHost

        protected void setHost​(java.lang.String host)

      • setPath

        protected void setPath​(java.lang.String path)

      • getPath

        public java.lang.String getPath()

      • initialize

        protected void initialize()
        Build the regular expression needed to parse log entries

      • updateCustomLevelDefinitionMap

        private void updateCustomLevelDefinitionMap()

      • isInteger

        private boolean isInteger​(java.lang.String value)

      • quoteTimeStampChars

        private java.lang.String quoteTimeStampChars​(java.lang.String input)

      • singleReplace

        private java.lang.String singleReplace​(java.lang.String inputString,
                                       java.lang.String oldString,
                                       java.lang.String newString)

      • getShortPropertyName

        private java.lang.String getShortPropertyName​(java.lang.String longPropertyName)

      • replaceMetaChars

        private java.lang.String replaceMetaChars​(java.lang.String input)
        Some perl5 characters may occur in the log file format. Escape these characters to prevent parsing errors.
        Parameters:
        input -
        Returns:
        string

      • convertToEvent

        private org.apache.log4j.spi.LoggingEvent convertToEvent​(java.util.Map fieldMap,
                                                         java.lang.String[] exception)
        Convert a keyword-to-values map to a LoggingEvent
        Parameters:
        fieldMap -
        exception -
        Returns:
        logging event

      • shutdown

        public void shutdown()
        Close the reader.

      • activateOptions

        public void activateOptions()
        Read and process the log file.