Logger (Common Logging 2.0.2 API)

All Known Implementing Classes:

CommonsLogger, LoggerBase
```
public interface Logger
```
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): trace (the least serious) debug info warn error fatal (the most serious) The mapping of these log levels to the concepts used by the underlying logging system is implementation dependent. The implementation should ensure, though, that this ordering behaves as expected. 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.

Author:

Tomas Teubner

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`debug(String message, Object... params)` Logs an error with debug log level.
`void`	`debug(String message, Throwable t, Object... params)` Logs an error with debug log level.
`void`	`error(String message, Object... params)` Logs an error with error log level.
`void`	`error(String message, Throwable t, Object... params)` Logs an error with error log level.
`void`	`fatal(String message, Object... params)` Logs an error with fatal log level.
`void`	`fatal(String message, Throwable t, Object... params)` Logs an error with fatal log level.
`void`	`info(String message, Object... params)` Logs an error with info log level.
`void`	`info(String message, Throwable t, Object... params)` Logs an error with info log level.
`boolean`	`isDebugEnabled()` Is debug logging currently enabled?
`boolean`	`isErrorEnabled()` Is error logging currently enabled?
`boolean`	`isFatalEnabled()` Is fatal logging currently enabled?
`boolean`	`isInfoEnabled()` Is info logging currently enabled?
`boolean`	`isTraceEnabled()` Is trace logging currently enabled?
`boolean`	`isWarnEnabled()` Is warning logging currently enabled?
`void`	`trace(String message, Object... params)` Logs an error with trace log level.
`void`	`trace(String message, Throwable t, Object... params)` Logs an error with trace log level.
`void`	`warn(String message, Object... params)` Logs an error with warning log level.
`void`	`warn(String message, Throwable t, Object... params)` Logs an error with warning log level.

- Method Detail
  - 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.
  - 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.
  - 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.
  - isWarnEnabled
```
boolean isWarnEnabled()
```
    Is warning logging currently enabled? Call this method to prevent having to perform expensive operations (for example, String concatenation) when the log level is more than warning.
    
    Returns:
    
    true if warning 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.
  - trace
```
void trace(String message,
           Object... params)
```
    Logs an error with trace log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    params - message parameters
  - trace
```
void trace(String message,
           Throwable t,
           Object... params)
```
    Logs an error with trace log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    t - log this cause
    
    params - message parameters
  - debug
```
void debug(String message,
           Object... params)
```
    Logs an error with debug log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    params - message parameters
  - debug
```
void debug(String message,
           Throwable t,
           Object... params)
```
    Logs an error with debug log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    t - log this cause
    
    params - message parameters
  - info
```
void info(String message,
          Object... params)
```
    Logs an error with info log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    params - message parameters
  - info
```
void info(String message,
          Throwable t,
          Object... params)
```
    Logs an error with info log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    t - log this cause
    
    params - message parameters
  - warn
```
void warn(String message,
          Object... params)
```
    Logs an error with warning log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    params - message parameters
  - warn
```
void warn(String message,
          Throwable t,
          Object... params)
```
    Logs an error with warning log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    t - log this cause
    
    params - message parameters
  - error
```
void error(String message,
           Object... params)
```
    Logs an error with error log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    params - message parameters
  - error
```
void error(String message,
           Throwable t,
           Object... params)
```
    Logs an error with error log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    t - log this cause
    
    params - message parameters
  - fatal
```
void fatal(String message,
           Object... params)
```
    Logs an error with fatal log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    params - message parameters
  - fatal
```
void fatal(String message,
           Throwable t,
           Object... params)
```
    Logs an error with fatal log level.
    
    Parameters:
    
    message - log this message format string (see String.format())
    
    t - log this cause
    
    params - message parameters

Interface Logger

Method Summary

Method Detail

isTraceEnabled

isDebugEnabled

isInfoEnabled

isWarnEnabled

isErrorEnabled

isFatalEnabled

trace

trace

debug

debug

info

info

warn

warn

error

error

fatal

fatal