Package org.apache.log4j.varia

Class LogFilePatternReceiver

  • All Implemented Interfaces:
    Plugin, Component, org.apache.log4j.spi.OptionHandler, Thresholdable
    Direct Known Subclasses:
    VFSLogFilePatternReceiver
    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) - 'group' property can be set to associate multiple log file receivers

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

    (NL) represents a new line embedded in the log format, supporting log formats whose fields span multiple lines

    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 - <test> <test2>something here</test2> <test3 blah=something/> <test4> <test5>something else</test5> </test4></test>
    880 [ Thread-2] DEBUG first.logger third - <test> <test2>something here</test2> <test3 blah=something/> <test4> <test5>something else</test5> </test4></test>
    880 [ Thread-0] INFO first.logger first - infomsg-0
    java.lang.Exception: someexception-first
    at Generator2.run(Generator2.java:102)

    Author:
    Scott Deboy

    • Field Detail

      • MISSING_FILE_RETRY_MILLIS

        public static final int MISSING_FILE_RETRY_MILLIS
        See Also:
        Constant Field Values

    • Constructor Detail

      • LogFilePatternReceiver

        public LogFilePatternReceiver()

    • Method Detail

      • getFileURL

        public String getFileURL()
        Accessor
        Returns:
        file URL

      • setFileURL

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

      • setCustomLevelDefinitions

        public void setCustomLevelDefinitions​(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 String getCustomLevelDefinitions()

      • isAppendNonMatches

        public boolean isAppendNonMatches()
        Accessor
        Returns:
        append non matches

      • setAppendNonMatches

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

      • getFilterExpression

        public String getFilterExpression()
        Accessor
        Returns:
        filter expression

      • setFilterExpression

        public void setFilterExpression​(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:

      • 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 String getLogFormat()
        Accessor
        Returns:
        log format

      • setLogFormat

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

      • setGroup

        public void setGroup​(String group)
        Mutator

      • getGroup

        public String getGroup()
        Accessor
        Returns:
        group

      • setTimestampFormat

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

      • getTimestampFormat

        public 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 -

      • process

        protected void process​(BufferedReader bufferedReader)
                throws 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:
        IOException

      • createPattern

        protected void createPattern()

      • setHost

        protected void setHost​(String host)

      • setPath

        protected void setPath​(String path)

      • getPath

        public String getPath()

      • initialize

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

      • shutdown

        public void shutdown()
        Close the reader.

      • activateOptions

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