public interface LogEventListener
If a LogEventListener is registered, the logger will call the LogEventListener when interesting Log Events occur. For example, the Logger will notify the LogEventListener when the current log file is 50% full to allow the application to copy old log entries forward.
If the application does not register a LogEventListener it will not have visibility to Log events.
Modifier and Type | Field and Description |
---|---|
static int |
DEBUG
used to log low level events.
|
static int |
ERROR
used to log non-fatal error messages.
|
static int |
FATAL
used to log fatal error messages that should cause
shutdown of the application using HOWL.
|
static int |
INFO
used to log information messages such as file open/close.
|
static int |
TRACE
used to trace method entry/exit and other low level events.
|
static int |
WARN
used to log warnings.
|
Modifier and Type | Method and Description |
---|---|
boolean |
isLoggable(int level)
determine if log messages for requested level will
be written to the log.
|
void |
log(int level,
String message)
write a log message to the event log.
|
void |
log(int level,
String message,
Throwable thrown)
write a log message to the event log with exception information.
|
void |
logOverflowNotification(long logkey)
Called by Logger to notify the LogEventListener
that a log file overflow is approaching.
|
static final int TRACE
static final int DEBUG
static final int INFO
static final int WARN
static final int ERROR
static final int FATAL
void logOverflowNotification(long logkey)
logkey
- lowest safe log key.
LogEventListener should cause log records with keys less than logkey to be copied forward to prevent a LogOverflowException.
Hopefully, the LogEventListener will be able to regenerate the records from memory without having to read the physical log file. For example, a Transaction Manager should maintain a table of transactions that are in the COMMITTING mode, with associated log key for each transaction. The logOverflowNotification method would call Logger.put() for each transaction that has a log key less than logKey .
Before returning from logOverflowNotification the LogEventListener should call Logger.mark(newMark, force) with force set to true to assure that the new records have been committed to physical disk.
boolean isLoggable(int level)
java.util.logging.Logger#isLoggable()
void log(int level, String message)
level
- log levelmessage
- text to be loggedCopyright © 2014 ObjectWeb HOWL. All rights reserved.