org.apache.commons.logging
Interface Log

All Known Implementing Classes:

AvalonLogger, Jdk13LumberjackLogger, Jdk14Logger, Log4JLogger, LogKitLogger, NoOpLog, SimpleLog

public interface Log

A simple logging interface abstracting logging APIs. In order to be instantiated successfully by LogFactory, classes that implement this interface must have a constructor that takes a single String parameter representing the "name" of this Log.

The six logging levels used by Log are (in order):

1. trace (the least serious)
2. debug
3. info
4. warn
5. error
6. fatal (the most serious)

Performance is often a logging concern. By examining the appropriate property, a component can avoid expensive operations (producing information to be logged).

For example,

    if (log.isDebugEnabled()) {
        ... do something expensive ...
        log.debug(theResult);
    }
 

Configuration of the underlying logging system will generally be done external to the Logging APIs, through whatever mechanism is supported by that system.

Version:

$Id: Log.java 1432663 2013-01-13 17:24:18Z tn $

isDebugEnabled

boolean isDebugEnabled()

Is debug logging currently enabled?

Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than debug.

Returns:

true if debug is enabled in the underlying logger.

isErrorEnabled

boolean isErrorEnabled()

Is error logging currently enabled?

Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than error.

Returns:

true if error is enabled in the underlying logger.

isFatalEnabled

boolean isFatalEnabled()

Is fatal logging currently enabled?

Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than fatal.

Returns:

true if fatal is enabled in the underlying logger.

isInfoEnabled

boolean isInfoEnabled()

Is info logging currently enabled?

Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than info.

Returns:

true if info is enabled in the underlying logger.

isTraceEnabled

boolean isTraceEnabled()

Is trace logging currently enabled?

Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than trace.

Returns:

true if trace is enabled in the underlying logger.

isWarnEnabled

boolean isWarnEnabled()

Is warn logging currently enabled?

Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than warn.

Returns:

true if warn is enabled in the underlying logger.

trace

void trace(Object message)

Log a message with trace log level.

Parameters:

message - log this message

trace

void trace(Object message,
           Throwable t)

Log an error with trace log level.

Parameters:

message - log this message

t - log this cause

debug

void debug(Object message)

Log a message with debug log level.

Parameters:

message - log this message

debug

void debug(Object message,
           Throwable t)

Log an error with debug log level.

Parameters:

message - log this message

t - log this cause

info

void info(Object message)

Log a message with info log level.

Parameters:

message - log this message

info

void info(Object message,
          Throwable t)

Log an error with info log level.

Parameters:

message - log this message

t - log this cause

warn

void warn(Object message)

Log a message with warn log level.

Parameters:

message - log this message

warn

void warn(Object message,
          Throwable t)

Log an error with warn log level.

Parameters:

message - log this message

t - log this cause

error

void error(Object message)

Log a message with error log level.

Parameters:

message - log this message

error

void error(Object message,
           Throwable t)

Log an error with error log level.

Parameters:

message - log this message

t - log this cause

fatal

void fatal(Object message)

Log a message with fatal log level.

Parameters:

message - log this message

fatal

void fatal(Object message,
           Throwable t)

Log an error with fatal log level.

Parameters:

message - log this message

t - log this cause