All Known Implementing Classes:

AbstractLogger, LoggerJDK13, LoggerJDK14
```
public interface Logger
```
This interface provides an isolation layer between the JDO components that need logging services and the implementation of those services.
The JDO Logger interface contains a small number of convenience methods in addition to a subset of the methods in the java.util.logging.Logger class, and can therefore be implemented in a very straightforward way by a subclass of the java.util.logging.Logger class. There is one instance of the implementing class for each subsystem in JDO.
This interface has no JDK 1.4 dependencies.

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`ALL`	ALL indicates that all messages should be logged.
`static int`	`CONFIG`	CONFIG is a message level for static configuration messages.
`static int`	`FINE`	FINE is a message level providing tracing information.
`static int`	`FINER`	FINER indicates a fairly detailed tracing message.
`static int`	`FINEST`	FINEST indicates a highly detailed tracing message
`static int`	`INFO`	INFO is a message level for informational messages.
`static int`	`OFF`	OFF is a special level that can be used to turn off logging.
`static int`	`SEVERE`	SEVERE is a message level indicating a serious failure.
`static int`	`WARNING`	WARNING is a message level indicating a potential problem.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`config(String msg)`	Log a CONFIG message.
`void`	`entering(String sourceClass, String sourceMethod)`	Log a method entry.
`void`	`entering(String sourceClass, String sourceMethod, Object param1)`	Log a method entry, with one parameter.
`void`	`entering(String sourceClass, String sourceMethod, Object[] params)`	Log a method entry, with an array of parameters.
`void`	`exiting(String sourceClass, String sourceMethod)`	Log a method return.
`void`	`exiting(String sourceClass, String sourceMethod, Object result)`	Log a method return, with result object.
`void`	`fine(String msg)`	Log a message.
`void`	`fine(String msg, Object o1)`	Log a FINE message.
`void`	`fine(String msg, Object[] o)`	Log a FINE message.
`void`	`fine(String msg, Object o1, Object o2)`	Log a FINE message.
`void`	`fine(String msg, Object o1, Object o2, Object o3)`	Log a FINE message.
`void`	`finer(String msg)`	Log a FINER message.
`void`	`finer(String msg, Object o1)`	Log a FINER message.
`void`	`finer(String msg, Object[] o)`	Log a FINER message.
`void`	`finer(String msg, Object o1, Object o2)`	Log a FINER message.
`void`	`finer(String msg, Object o1, Object o2, Object o3)`	Log a FINER message.
`void`	`finest(String msg)`	Log a FINEST message.
`void`	`finest(String msg, Object o1)`	Log a FINEST message.
`void`	`finest(String msg, Object[] o)`	Log a FINEST message.
`void`	`finest(String msg, Object o1, Object o2)`	Log a FINEST message.
`void`	`finest(String msg, Object o1, Object o2, Object o3)`	Log a FINEST message.
`String`	`getName()`	Get the name for this logger.
`void`	`info(String msg)`	Log an INFO message.
`boolean`	`isLoggable()`	Test if this logger is logging messages.
`boolean`	`isLoggable(int level)`	Test if this logger is logging messages at the specific level.
`void`	`log(int level, String msg)`	Log a message.
`void`	`log(int level, String msg, Object o1)`	Log a message.
`void`	`log(int level, String msg, Object[] o)`	Log a message.
`void`	`log(int level, String msg, Object o1, Object o2)`	Log a message.
`void`	`log(int level, String msg, Object o1, Object o2, Object o3)`	Log a message.
`void`	`log(int level, String msg, Throwable thrown)`	Log a message.
`void`	`severe(String msg)`	Log a SEVERE message.
`void`	`throwing(String sourceClass, String sourceMethod, Throwable thrown)`	Log throwing an exception.
`void`	`warning(String msg)`	Log a WARNING message.

- Field Detail
  - OFF
```
static final int OFF
```
    OFF is a special level that can be used to turn off logging.
    
    See Also:
    
    Constant Field Values
  - SEVERE
```
static final int SEVERE
```
    SEVERE is a message level indicating a serious failure.
    In general SEVERE messages should describe events that are of considerable importance and which will prevent normal program execution. They should be reasonably intelligible to end users and to system administrators.
    
    See Also:
    
    Constant Field Values
  - WARNING
```
static final int WARNING
```
    WARNING is a message level indicating a potential problem.
    In general WARNING messages should describe events that will be of interest to end users or system managers, or which indicate potential problems.
    
    See Also:
    
    Constant Field Values
  - INFO
```
static final int INFO
```
    INFO is a message level for informational messages.
    Typically INFO messages will be written to the console or its equivalent. So the INFO level should only be used for reasonably significant messages that will make sense to end users and system admins.
    
    See Also:
    
    Constant Field Values
  - CONFIG
```
static final int CONFIG
```
    CONFIG is a message level for static configuration messages.
    CONFIG messages are intended to provide a variety of static configuration information, to assist in debugging problems that may be associated with particular configurations. For example, CONFIG message might include the CPU type, the graphics depth, the GUI look-and-feel, etc.
    
    See Also:
    
    Constant Field Values
  - FINE
```
static final int FINE
```
    FINE is a message level providing tracing information.
    All of FINE, FINER, and FINEST are intended for relatively detailed tracing. The exact meaning of the three levels will vary between subsystems, but in general, FINEST should be used for the most voluminous detailed output, FINER for somewhat less detailed output, and FINE for the lowest volume (and most important) messages.
    In general the FINE level should be used for information that will be broadly interesting to developers who do not have a specialized interest in the specific subsystem.
    FINE messages might include things like minor (recoverable) failures. Issues indicating potential performance problems are also worth logging as FINE.
    
    See Also:
    
    Constant Field Values
  - FINER
```
static final int FINER
```
    FINER indicates a fairly detailed tracing message. By default logging calls for entering, returning, or throwing an exception are traced at this level.
    
    See Also:
    
    Constant Field Values
  - FINEST
```
static final int FINEST
```
    FINEST indicates a highly detailed tracing message
    
    See Also:
    
    Constant Field Values
  - ALL
```
static final int ALL
```
    ALL indicates that all messages should be logged.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - isLoggable
```
boolean isLoggable()
```
    Test if this logger is logging messages. This is a test for log level FINE, FINER, or FINEST. If the log message is expensive to construct, this method should be used to determine whether it is a waste of time. We don't expose isLoggable(Level) because Level is not available in JDK 1.3. Once this is not an issue, we can add isLoggable(Level).
    
    Returns:
    
    if FINE, FINER, or FINEST is currently being logged
  - isLoggable
```
boolean isLoggable(int level)
```
    Test if this logger is logging messages at the specific level. If the log message is expensive to construct, this method should be used to determine whether it is a waste of time. We don't expose isLoggable(Level) because Level is not available in JDK 1.3. Once this is not an issue, we can add isLoggable(Level).
    
    Parameters:
    
    level - The level to be tested
    
    Returns:
    
    if this level is currently being logged
  - entering
```
void entering(String sourceClass,
              String sourceMethod)
```
    Log a method entry.
    This is a convenience method that can be used to log entry to a method. A LogRecord with message "ENTRY", log level FINER, and the given sourceMethod and sourceClass is logged.
    
    Parameters:
    
    sourceClass - name of class that issued the logging request
    
    sourceMethod - name of method that is being entered
  - entering
```
void entering(String sourceClass,
              String sourceMethod,
              Object param1)
```
    Log a method entry, with one parameter.
    This is a convenience method that can be used to log entry to a method. A LogRecord with message "ENTRY {0}", log level FINER, and the given sourceMethod, sourceClass, and parameter is logged.
    
    Parameters:
    
    sourceClass - name of class that issued the logging request
    
    sourceMethod - name of method that is being entered
    
    param1 - parameter to the method being entered
  - entering
```
void entering(String sourceClass,
              String sourceMethod,
              Object[] params)
```
    Log a method entry, with an array of parameters.
    This is a convenience method that can be used to log entry to a method. A LogRecord with message "ENTRY" (followed by a format {N} indicator for each entry in the parameter array), log level FINER, and the given sourceMethod, sourceClass, and parameters is logged.
    
    Parameters:
    
    sourceClass - name of class that issued the logging request
    
    sourceMethod - name of method that is being entered
    
    params - array of parameters to the method being entered
  - exiting
```
void exiting(String sourceClass,
             String sourceMethod)
```
    Log a method return.
    This is a convenience method that can be used to log returning from a method. A LogRecord with message "RETURN", log level FINER, and the given sourceMethod and sourceClass is logged.
    
    Parameters:
    
    sourceClass - name of class that issued the logging request
    
    sourceMethod - name of the method
  - exiting
```
void exiting(String sourceClass,
             String sourceMethod,
             Object result)
```
    Log a method return, with result object.
    This is a convenience method that can be used to log returning from a method. A LogRecord with message "RETURN {0}", log level FINER, and the gives sourceMethod, sourceClass, and result object is logged.
    
    Parameters:
    
    sourceClass - name of class that issued the logging request
    
    sourceMethod - name of the method
    
    result - Object that is being returned
  - throwing
```
void throwing(String sourceClass,
              String sourceMethod,
              Throwable thrown)
```
    Log throwing an exception.
    This is a convenience method to log that a method is terminating by throwing an exception. The logging is done using the FINER level.
    If the logger is currently enabled for the given message level then the given arguments are stored in a LogRecord which is forwarded to all registered output handlers. The LogRecord's message is set to "THROW".
    Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus is it processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
    
    Parameters:
    
    sourceClass - name of class that issued the logging request
    
    sourceMethod - name of the method.
    
    thrown - The Throwable that is being thrown.
  - severe
```
void severe(String msg)
```
    Log a SEVERE message.
    If the logger is currently enabled for the SEVERE message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - warning
```
void warning(String msg)
```
    Log a WARNING message.
    If the logger is currently enabled for the WARNING message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - info
```
void info(String msg)
```
    Log an INFO message.
    If the logger is currently enabled for the INFO message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - config
```
void config(String msg)
```
    Log a CONFIG message.
    If the logger is currently enabled for the CONFIG message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - log
```
void log(int level,
         String msg)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    level - The level for this message
    
    msg - The string message (or a key in the message catalog)
  - log
```
void log(int level,
         String msg,
         Object o1)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    level - The level for this message
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
  - log
```
void log(int level,
         String msg,
         Object[] o)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    level - The level for this message
    
    msg - The string message (or a key in the message catalog)
    
    o - Objects to be inserted into the message
  - log
```
void log(int level,
         String msg,
         Object o1,
         Object o2)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    level - The level for this message
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
  - log
```
void log(int level,
         String msg,
         Object o1,
         Object o2,
         Object o3)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    level - The level for this message
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
    
    o3 - A parameter to be inserted into the message
  - log
```
void log(int level,
         String msg,
         Throwable thrown)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message, and the exception dump, is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    level - The level for this message
    
    msg - The string message (or a key in the message catalog)
    
    thrown - The exception to log
  - fine
```
void fine(String msg)
```
    Log a message.
    If the logger is currently enabled for the message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - fine
```
void fine(String msg,
          Object o1)
```
    Log a FINE message.
    If the logger is currently enabled for the FINE message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
  - fine
```
void fine(String msg,
          Object[] o)
```
    Log a FINE message.
    If the logger is currently enabled for the FINE message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o - Objects to be inserted into the message
  - fine
```
void fine(String msg,
          Object o1,
          Object o2)
```
    Log a FINE message.
    If the logger is currently enabled for the FINE message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
  - fine
```
void fine(String msg,
          Object o1,
          Object o2,
          Object o3)
```
    Log a FINE message.
    If the logger is currently enabled for the FINE message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
    
    o3 - A parameter to be inserted into the message
  - finer
```
void finer(String msg)
```
    Log a FINER message.
    If the logger is currently enabled for the FINER message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - finer
```
void finer(String msg,
           Object[] o)
```
    Log a FINER message.
    If the logger is currently enabled for the FINER message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o - Objects to be inserted into the message
  - finer
```
void finer(String msg,
           Object o1)
```
    Log a FINER message.
    If the logger is currently enabled for the FINER message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
  - finer
```
void finer(String msg,
           Object o1,
           Object o2)
```
    Log a FINER message.
    If the logger is currently enabled for the FINER message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
  - finer
```
void finer(String msg,
           Object o1,
           Object o2,
           Object o3)
```
    Log a FINER message.
    If the logger is currently enabled for the FINER message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
    
    o3 - A parameter to be inserted into the message
  - finest
```
void finest(String msg)
```
    Log a FINEST message.
    If the logger is currently enabled for the FINEST message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
  - finest
```
void finest(String msg,
            Object[] o)
```
    Log a FINEST message.
    If the logger is currently enabled for the FINEST message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o - Objects to be inserted into the message
  - finest
```
void finest(String msg,
            Object o1)
```
    Log a FINEST message.
    If the logger is currently enabled for the FINEST message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
  - finest
```
void finest(String msg,
            Object o1,
            Object o2)
```
    Log a FINEST message.
    If the logger is currently enabled for the FINEST message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
  - finest
```
void finest(String msg,
            Object o1,
            Object o2,
            Object o3)
```
    Log a FINEST message.
    If the logger is currently enabled for the FINEST message level then the given message is forwarded to all the registered output Handler objects.
    
    Parameters:
    
    msg - The string message (or a key in the message catalog)
    
    o1 - A parameter to be inserted into the message
    
    o2 - A parameter to be inserted into the message
    
    o3 - A parameter to be inserted into the message
  - getName
```
String getName()
```
    Get the name for this logger.
    
    Returns:
    
    logger name. Will be null for anonymous Loggers.

Interface Logger

Field Summary

Method Summary

Field Detail

OFF

SEVERE

WARNING

INFO

CONFIG

FINE

FINER

FINEST

ALL

Method Detail

isLoggable

isLoggable

entering

entering

entering

exiting

exiting

throwing

severe

warning

info

config

log

log

log

log

log

log

fine

fine

fine

fine

fine

finer

finer

finer

finer

finer

finest

finest

finest

finest

finest

getName