LoggingEventFieldResolver (Apache Extras™ for Apache log4j™. 1.2.17 API)

java.lang.Object
- org.apache.log4j.spi.LoggingEventFieldResolver

```
public final class LoggingEventFieldResolver
extends 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.

Author:

Scott Deboy ([email protected]), Paul Smith ([email protected])

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CLASS_FIELD` CLASS string literal.
`static String`	`EMPTY_STRING` empty string literal.
`static String`	`EXCEPTION_FIELD` EXCEPTION string literal.
`static String`	`FILE_FIELD` FILE string literal.
`static List`	`KEYWORD_LIST` Keyword list.
`static String`	`LEVEL_FIELD` LEVEL string literal.
`static String`	`LINE_FIELD` LINE string literal.
`static String`	`LOGGER_FIELD` LOGGER string literal.
`static String`	`METHOD_FIELD` METHOD string literal.
`static String`	`MSG_FIELD` MSG string literal.
`static String`	`NDC_FIELD` NDC string literal.
`static String`	`PROP_FIELD` PROP. string literal.
`static String`	`THREAD_FIELD` THREAD string literal.
`static String`	`TIMESTAMP_FIELD` TIMESTAMP string literal.

Method Summary

Methods
Modifier and Type	Method and Description
`String`	`applyFields(String replaceText, org.apache.log4j.spi.LoggingEvent event)` Apply fields.
`static LoggingEventFieldResolver`	`getInstance()` Get singleton instance.
`Object`	`getValue(String fieldName, org.apache.log4j.spi.LoggingEvent event)` Get value of field.
`boolean`	`isField(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 List KEYWORD_LIST
```
    Keyword list.
  - LOGGER_FIELD
```
public static final String LOGGER_FIELD
```
    LOGGER string literal.
    
    See Also:
    Constant Field Values
  - LEVEL_FIELD
```
public static final String LEVEL_FIELD
```
    LEVEL string literal.
    
    See Also:
    Constant Field Values
  - CLASS_FIELD
```
public static final String CLASS_FIELD
```
    CLASS string literal.
    
    See Also:
    Constant Field Values
  - FILE_FIELD
```
public static final String FILE_FIELD
```
    FILE string literal.
    
    See Also:
    Constant Field Values
  - LINE_FIELD
```
public static final String LINE_FIELD
```
    LINE string literal.
    
    See Also:
    Constant Field Values
  - METHOD_FIELD
```
public static final String METHOD_FIELD
```
    METHOD string literal.
    
    See Also:
    Constant Field Values
  - MSG_FIELD
```
public static final String MSG_FIELD
```
    MSG string literal.
    
    See Also:
    Constant Field Values
  - NDC_FIELD
```
public static final String NDC_FIELD
```
    NDC string literal.
    
    See Also:
    Constant Field Values
  - EXCEPTION_FIELD
```
public static final String EXCEPTION_FIELD
```
    EXCEPTION string literal.
    
    See Also:
    Constant Field Values
  - TIMESTAMP_FIELD
```
public static final String TIMESTAMP_FIELD
```
    TIMESTAMP string literal.
    
    See Also:
    Constant Field Values
  - THREAD_FIELD
```
public static final String THREAD_FIELD
```
    THREAD string literal.
    
    See Also:
    Constant Field Values
  - PROP_FIELD
```
public static final String PROP_FIELD
```
    PROP. string literal.
    
    See Also:
    Constant Field Values
  - EMPTY_STRING
```
public static final String EMPTY_STRING
```
    empty string literal.
    
    See Also:
    Constant Field Values
- Method Detail
  - applyFields
```
public String applyFields(String replaceText,
                 org.apache.log4j.spi.LoggingEvent event)
```
    Apply fields.
    
    Parameters:
    replaceText - replacement text.
    event - logging event.
    
    Returns:
    evaluted expression
  - getInstance
```
public static LoggingEventFieldResolver getInstance()
```
    Get singleton instance.
    
    Returns:
    singleton instance
  - isField
```
public boolean isField(String fieldName)
```
    Determines if specified string is a recognized field.
    
    Parameters:
    fieldName - field name
    
    Returns:
    true if recognized field.
  - getValue
```
public Object getValue(String fieldName,
              org.apache.log4j.spi.LoggingEvent event)
```
    Get value of field.
    
    Parameters:
    fieldName - field
    event - event
    
    Returns:
    value of field

Class LoggingEventFieldResolver

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

KEYWORD_LIST

LOGGER_FIELD

LEVEL_FIELD

CLASS_FIELD

FILE_FIELD

LINE_FIELD

METHOD_FIELD

MSG_FIELD

NDC_FIELD

EXCEPTION_FIELD

TIMESTAMP_FIELD

THREAD_FIELD

PROP_FIELD

EMPTY_STRING

Method Detail

applyFields

getInstance

isField

getValue