se.kth.cid.util
Class Tracer

java.lang.Object
  |
  +--se.kth.cid.util.Tracer

public class Tracer

extends Object

This class is used for debugging and for putting trace printouts in code that may be controlled at runtime.

The printouts are controlled by a global log level When a trace is given to this class, it checks whether the trace is this log level or higher, and then proceeds to print it. Otherwise the trace is simply ignored. Debug traces cannot be turned off, though.

Version:

$Revision: 1.1.1.1 $

Author:

Mikael Nilsson

Field Summary

static int	ALL Use to get all traces.
static int	BUG Programming error of some kind, that is only caused by a bug in the program.
static int	DEBUG Will always be reported.
static int	DETAIL Details from the inner workings.
static int	ERROR Serious error in the program, that may be difficult to recover from.
static int	MAJOR_EXT_EVENT Larger, externally visible event.
static int	MAJOR_INT_EVENT Larger, internally visible event (implementation dependent)
static int	MINOR_EXT_EVENT Lesser, externally visible event (e.g.
static int	MINOR_INT_EVENT Lesser, internally visible event (implementation dependent)
static int	NONE Use this as log level to never get any traces (except DEBUGs)
static String[]	TRACESTR Array of the strings that are used to report the above levels.
static int	WARNING Less serious errors that will not cause immediate problems.

Method Summary

static void	bug(String trace) Used when a bug has been discovered.
static void	debug(String trace) Used to debug program action.
static void	error(String trace) Used when a serious error has occured, from which recovery is not foreseen.
static String	getTraceStr(int nlogLevel) Returns the trace string for the given log level, i.e.
static int	parseLogLevel(String level) Returns the loglevel represented by the string.
static void	setLogLevel(int nlogLevel) Used to change the log level.
static void	trace(String trace, int thisLogLevel) Used to trace program action.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEBUG

public static final int DEBUG

Will always be reported.

BUG

public static final int BUG

Programming error of some kind, that is only caused by a bug in the program. Illegal arguments are included here.

ERROR

public static final int ERROR

Serious error in the program, that may be difficult to recover from. but that can occur without programming errors.

WARNING

public static final int WARNING

Less serious errors that will not cause immediate problems.

MAJOR_EXT_EVENT

public static final int MAJOR_EXT_EVENT

Larger, externally visible event.

MINOR_EXT_EVENT

public static final int MINOR_EXT_EVENT

Lesser, externally visible event (e.g. state change).

MAJOR_INT_EVENT

public static final int MAJOR_INT_EVENT

Larger, internally visible event (implementation dependent)

MINOR_INT_EVENT

public static final int MINOR_INT_EVENT

Lesser, internally visible event (implementation dependent)

DETAIL

public static final int DETAIL

Details from the inner workings. The DETAIL + n levels are allowed, but are defined by the application, and are reported as "DETAILn".

NONE

public static final int NONE

Use this as log level to never get any traces (except DEBUGs)

ALL

public static final int ALL

Use to get all traces.

TRACESTR

public static final String[] TRACESTR

Array of the strings that are used to report the above levels.

Method Detail

parseLogLevel

public static int parseLogLevel(String level)

Returns the loglevel represented by the string.

Parameters:

nLogLevelStr - a string representing a loglevel.

Returns:

the loglevel represented by the string, or -1.

Throws:

IllegalArgumentException - if the loglevel is invalid.

setLogLevel

public static void setLogLevel(int nlogLevel)

Used to change the log level.

Parameters:

nlogLevel - the new log level. Must be positive or zero.

getTraceStr

public static String getTraceStr(int nlogLevel)

Returns the trace string for the given log level, i.e. the string used as label for printouts for traces at this log level.

Parameters:

nlogLevel - the log level to convert to a String.

Returns:

A string representing the log level.

trace

public static void trace(String trace,
                         int thisLogLevel)

Used to trace program action.

Parameters:

trace - the string to display.

thisLogLevel - the loglevel of this trace.

error

public static void error(String trace)
                  throws Error

Used when a serious error has occured, from which recovery is not foreseen. Will throw an Error with the given message, as well as issue a trace with level Tracer.ERROR.

Parameters:

trace - the string to display.

Throws:

Error - always thrown.

bug

public static void bug(String trace)
                throws Error

Used when a bug has been discovered. Will throw an Error with the given message, as well as issue a trace with level Tracer.BUG.

Parameters:

trace - the string to display.

Throws:

Error - always thrown.

debug

public static void debug(String trace)

Used to debug program action. Actually shorthand for
Tracer.trace(trace, Tracer.DEBUG)

Parameters:

trace - the string to display.