Logger (JUG)

java.lang.Object
- org.safehaus.uuid.Logger

Direct Known Subclasses:

JavaUtilLogger, Log4jLogger
```
public class Logger
extends Object
```
This is the simple logging interface used by JUG package. It is meant to provide a minimal but sufficient functionality for JUG to report problems (warnings, errors), in a way that it can be sufficiently customized (redirected, suppressed; even redefined), without forcing overhead of a real full-featured logging sub-system (like log4j or java.util.logging). By being customizable, it is still possible to connect JUG logging into such a real logging framework (log4j, java.util.logging) when being used in a system that already uses such a framework.
To keep things as light-weight as possible, we won't bother defining separate interface or abstract class -- this class defines both API and the default implementation. It can thus be extended to override functionality to provide thigs like bridging to "real" logging systems. For simple configuration (suppress all, redirect to another stream) default implementation should be sufficient, however.
Note: package org.safehaus.uuid.ext does contain simple wrappers to connect JUG logging to log4j and java.util.logging:

See Also:

Log4jLogger, JavaUtilLogger

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`LOG_ALL`
`static int`	`LOG_ERROR_AND_ABOVE`
`static int`	`LOG_INFO_AND_ABOVE`
`static int`	`LOG_NOTHING`
`static int`	`LOG_WARNING_AND_ABOVE`
`protected int`	`mLogLevel` Threshold to use for outputting varius log statements.
`protected PrintStream`	`mOutput1` Output object to use, if defined; initialized to `System.err`.
`protected PrintWriter`	`mOutput2` Override output used to explicitly specify where to pass diagnostic output, instead of System.err.

Constructor Summary

Constructors
Modifier Constructor and Description

protected Logger()

Constructors
Modifier	Constructor and Description
`protected`	`Logger()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`doLogError(String msg)`
`protected void`	`doLogInfo(String msg)`
`protected void`	`doLogWarning(String msg)`
`protected void`	`doSetLogLevel(int ll)`
`protected void`	`doSetOutput(PrintStream str)`
`protected void`	`doSetOutput(Writer w)`
`protected void`	`doWrite(String msg)`
`protected boolean`	`isEnabled()` Internal method used to quickly check if the Logger's output is suppressed or not.
`static void`	`logError(String msg)`
`static void`	`logInfo(String msg)`
`static void`	`logWarning(String msg)`
`static void`	`setLogger(Logger inst)` Method that can be used to completely re-define the logging functionality JUG uses.
`static void`	`setLogLevel(int level)` Method to set the minimum level of messages that will get logged using currently specific logger instace.
`static void`	`setOutput(PrintStream str)` Method that will re-direct output of the logger using the specified `PrintStream`.
`static void`	`setOutput(Writer w)` Method that will re-direct output of the logger using the specified `Writer`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - LOG_ALL
```
public static final int LOG_ALL
```
    See Also:
    
    Constant Field Values
  - LOG_INFO_AND_ABOVE
```
public static final int LOG_INFO_AND_ABOVE
```
    See Also:
    
    Constant Field Values
  - LOG_WARNING_AND_ABOVE
```
public static final int LOG_WARNING_AND_ABOVE
```
    See Also:
    
    Constant Field Values
  - LOG_ERROR_AND_ABOVE
```
public static final int LOG_ERROR_AND_ABOVE
```
    See Also:
    
    Constant Field Values
  - LOG_NOTHING
```
public static final int LOG_NOTHING
```
    See Also:
    
    Constant Field Values
  - mLogLevel
```
protected int mLogLevel
```
    Threshold to use for outputting varius log statements.
    Default is to low only warnings and errors
  - mOutput1
```
protected PrintStream mOutput1
```
    Output object to use, if defined; initialized to System.err.
  - mOutput2
```
protected PrintWriter mOutput2
```
    Override output used to explicitly specify where to pass diagnostic output, instead of System.err. Used if mOutput1 is null;
- Constructor Detail
  - Logger
```
protected Logger()
```
- Method Detail
  - setLogger
```
public static void setLogger(Logger inst)
```
    Method that can be used to completely re-define the logging functionality JUG uses. When called, JUG will start using the new instance; if instance passed is null, will basically suppress all logging.
    
    Parameters:
    
    inst - Logger instance to use for all logging JUG does; can be null, but if so, essentially disables all logging.
  - setLogLevel
```
public static void setLogLevel(int level)
```
    Method to set the minimum level of messages that will get logged using currently specific logger instace. For example, if LOG_WARNING_AND_ABOVE is passed as the argument, warnings and errors will be logged, but informational (INFO) messages will not.
    Note: exact functionality invoked depends on the logger instance: sub-classes of this class may need to do mapping to some other logging sub-system (log4j and JUL logging, for example, use their own severity levels that while generally reasonably easy to map, are nonetheless not one-to-one which the simple logger).
  - setOutput
```
public static void setOutput(PrintStream str)
```
    Method that will re-direct output of the logger using the specified PrintStream. Null is allowed, and signifies that all the output should be suppressed.
    Note: exact functionality invoked depends on the logger instance.
  - setOutput
```
public static void setOutput(Writer w)
```
    Method that will re-direct output of the logger using the specified Writer. Null is allowed, and signifies that all the output should be suppressed.
  - logInfo
```
public static void logInfo(String msg)
```
  - logWarning
```
public static void logWarning(String msg)
```
  - logError
```
public static void logError(String msg)
```
  - doSetLogLevel
```
protected void doSetLogLevel(int ll)
```
  - doSetOutput
```
protected void doSetOutput(PrintStream str)
```
  - doSetOutput
```
protected void doSetOutput(Writer w)
```
  - doLogInfo
```
protected void doLogInfo(String msg)
```
  - doLogWarning
```
protected void doLogWarning(String msg)
```
  - doLogError
```
protected void doLogError(String msg)
```
  - doWrite
```
protected void doWrite(String msg)
```
  - isEnabled
```
protected boolean isEnabled()
```
    Internal method used to quickly check if the Logger's output is suppressed or not.
    Note: not synchronized since it's read-only method that's return value can not be used for reliable syncing.

Class Logger

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG_ALL

LOG_INFO_AND_ABOVE

LOG_WARNING_AND_ABOVE

LOG_ERROR_AND_ABOVE

LOG_NOTHING

mLogLevel

mOutput1

mOutput2

Constructor Detail

Logger

Method Detail

setLogger

setLogLevel

setOutput

setOutput

logInfo

logWarning

logError

doSetLogLevel

doSetOutput

doSetOutput

doLogInfo

doLogWarning

doLogError

doWrite

isEnabled