Package org.apache.log4j.spi

Class LoggingEventFieldResolver

  • public final class LoggingEventFieldResolver
extends java.lang.Object
    A singleton helper utility which accepts a field name and a LoggingEvent and returns the value of that field. This class defines a grammar used in creation of an expression-based Rule. The only available method is Object getField(String fieldName, LoggingEvent event). Here is a description of the mapping of field names in the grammar to fields on the logging event. While the getField method returns an Object, the individual types returned per field are described here: Field Name Field value (String representation Return type LOGGER category name (logger) String LEVEL level Level CLASS locationInformation's class name String FILE locationInformation's file name String LINE locationInformation's line number String METHOD locationInformation's method name String MSG message Object NDC NDC String EXCEPTION throwable string representation ThrowableInformation TIMESTAMP timestamp Long THREAD thread String PROP.keyName entry in the Property hashtable String mapped to the key [keyName] NOTE: the values for the 'keyName' portion of the MDC and PROP mappings must be an exact match to the key in the hashTable (case sensitive). If the passed-in field is null or doesn't match an entry in the above-described mapping, an exception is thrown.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String applyFields​(java.lang.String replaceText, org.apache.log4j.spi.LoggingEvent event)
      Apply fields.
      private static java.lang.String getExceptionMessage​(java.lang.String[] exception)
      Get message from throwable representation.
      static LoggingEventFieldResolver getInstance()
      Get singleton instance.
      java.lang.Object getValue​(java.lang.String fieldName, org.apache.log4j.spi.LoggingEvent event)
      Get value of field.
      boolean isField​(java.lang.String fieldName)
      Determines if specified string is a recognized field.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • KEYWORD_LIST

        public static final java.util.List KEYWORD_LIST
        Keyword list.

      • LOGGER_FIELD

        public static final java.lang.String LOGGER_FIELD
        LOGGER string literal.
        See Also:
        Constant Field Values

      • LEVEL_FIELD

        public static final java.lang.String LEVEL_FIELD
        LEVEL string literal.
        See Also:
        Constant Field Values

      • CLASS_FIELD

        public static final java.lang.String CLASS_FIELD
        CLASS string literal.
        See Also:
        Constant Field Values

      • FILE_FIELD

        public static final java.lang.String FILE_FIELD
        FILE string literal.
        See Also:
        Constant Field Values

      • LINE_FIELD

        public static final java.lang.String LINE_FIELD
        LINE string literal.
        See Also:
        Constant Field Values

      • METHOD_FIELD

        public static final java.lang.String METHOD_FIELD
        METHOD string literal.
        See Also:
        Constant Field Values

      • MSG_FIELD

        public static final java.lang.String MSG_FIELD
        MSG string literal.
        See Also:
        Constant Field Values

      • NDC_FIELD

        public static final java.lang.String NDC_FIELD
        NDC string literal.
        See Also:
        Constant Field Values

      • EXCEPTION_FIELD

        public static final java.lang.String EXCEPTION_FIELD
        EXCEPTION string literal.
        See Also:
        Constant Field Values

      • TIMESTAMP_FIELD

        public static final java.lang.String TIMESTAMP_FIELD
        TIMESTAMP string literal.
        See Also:
        Constant Field Values

      • THREAD_FIELD

        public static final java.lang.String THREAD_FIELD
        THREAD string literal.
        See Also:
        Constant Field Values

      • PROP_FIELD

        public static final java.lang.String PROP_FIELD
        PROP. string literal.
        See Also:
        Constant Field Values

      • EMPTY_STRING

        public static final java.lang.String EMPTY_STRING
        empty string literal.
        See Also:
        Constant Field Values

    • Constructor Detail

      • LoggingEventFieldResolver

        private LoggingEventFieldResolver()
        Create new instance.

    • Method Detail

      • applyFields

        public java.lang.String applyFields​(java.lang.String replaceText,
                                    org.apache.log4j.spi.LoggingEvent event)
        Apply fields.
        Parameters:
        replaceText - replacement text.
        event - logging event.
        Returns:
        evaluted expression

      • isField

        public boolean isField​(java.lang.String fieldName)
        Determines if specified string is a recognized field.
        Parameters:
        fieldName - field name
        Returns:
        true if recognized field.

      • getValue

        public java.lang.Object getValue​(java.lang.String fieldName,
                                 org.apache.log4j.spi.LoggingEvent event)
        Get value of field.
        Parameters:
        fieldName - field
        event - event
        Returns:
        value of field

      • getExceptionMessage

        private static java.lang.String getExceptionMessage​(java.lang.String[] exception)
        Get message from throwable representation.
        Parameters:
        exception - exception
        Returns:
        message