ca.randolf.io

Class Log

Object

Thread

ca.randolf.io.Log

All Implemented Interfaces:

Runnable

public class Log
extends Thread

Records information in query logs and error logs. By default, the log output is sent to STDOUT and STDERR, unless a path is specified, in which case filenames are rotated automatically based on year and month (default, if a different date format is not specified).

Log file output is flushed automatically after there are no other entries waiting in the internal queue of log entries.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Log.Entry Log entry object. This is used internally for more efficient handling of log entries on the single internal queue.

Nested classes/interfaces inherited from class Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field and Description
static java.time.format.DateTimeFormatter	CCYY_MM Partial date (year and month) used in the construction of log filenames.
static int	ERR Log.Entry error type (a.k.a., STDERR).
static int	LOG Log.Entry non-error type (a.k.a., STDOUT).
static java.time.format.DateTimeFormatter	TSTAMP Full timestamp (date and time with timezone) included in log entries.
static String	VERSION Version number of this Package (read-only).

Fields inherited from class Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
Log() Create a Log object that writes its output to STDOUT and STDERR.
Log(java.nio.file.Path path) Create a Log object that writes its output to "${DATE}.log" and its errors to "${DATE}.err" in the specified path. "CCYY-MM" is the default format for the ${DATE} variable.
Log(java.nio.file.Path path, String fnOut, boolean stdout, String fnErr, boolean stderr) Create a Log object.
Log(java.nio.file.Path path, String fnOut, String fnErr) Create a Log object.
Log(String path) Create a Log object that writes its output to "${DATE}.log" and its errors to "${DATE}.err" in the specified path. "CCYY-MM" is the default format for the ${DATE} variable.
Log(String path, String fnOut, boolean stdout, String fnErr, boolean stderr) Create a Log object.
Log(String path, String fnOut, String fnErr) Create a Log object.

Method Summary

Modifier and Type	Method and Description
Log.Entry	add(String msg) Add a normal log entry to the internal queue for logged output that is akin to sending to stdout.
Log.Entry	add(String pre, String msg) Add a normal log entry to the internal queue for logged output that is akin to sending to stdout.
Log.Entry	err(String msg) Add an error log entry to the internal queue for logged output that is akin to sending to stderr.
Log.Entry	err(String pre, String msg) Add an error log entry to the internal queue for logged output that is akin to sending to stderr.
void	run() Background task.
String	toString() Provide debug-readable output version of this object.

Methods inherited from class Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, yield

Methods inherited from class Object

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

Field Detail

CCYY_MM

public static final java.time.format.DateTimeFormatter CCYY_MM

Partial date (year and month) used in the construction of log filenames.

ERR

public static final int ERR

Log.Entry error type (a.k.a., STDERR).

See Also:

Constant Field Values

LOG

public static final int LOG

Log.Entry non-error type (a.k.a., STDOUT).

See Also:

Constant Field Values

TSTAMP

public static final java.time.format.DateTimeFormatter TSTAMP

Full timestamp (date and time with timezone) included in log entries.

VERSION

public static final String VERSION

Version number of this Package (read-only).

See Also:

Constant Field Values

Constructor Detail

Log

public Log()

Create a Log object that writes its output to STDOUT and STDERR.

Log

public Log(java.nio.file.Path path)

Create a Log object that writes its output to "${DATE}.log" and its errors to "${DATE}.err" in the specified path. "CCYY-MM" is the default format for the ${DATE} variable.

Parameters:

path - Path where log files are to be created

Log

public Log(java.nio.file.Path path,
           String fnOut,
           boolean stdout,
           String fnErr,
           boolean stderr)

Create a Log object.

Parameters:

path - Path where log files are to be created and written to

fnOut - Base query log filename (before the ".CCYY-MM.log" portion)

stdout - Output to STDOUT in tandem with log file output (overrides to TRUE if fnOut is NULL)

fnErr - Base error log filename (before the ".CCYY-MM.log" portion)

stderr - Output to STDERR in tandem with err file output (overrides to TRUE if fnErr is NULL)

Log

public Log(java.nio.file.Path path,
           String fnOut,
           String fnErr)

Create a Log object.

Parameters:

path - Path where log files are to be created and written to

fnOut - Base query log filename (before the ".CCYY-MM.log" portion)

fnErr - Base error log filename (before the ".CCYY-MM.log" portion)

Log

public Log(String path)

Create a Log object that writes its output to "${DATE}.log" and its errors to "${DATE}.err" in the specified path. "CCYY-MM" is the default format for the ${DATE} variable.

Parameters:

path - Path where log files are to be created

Log

public Log(String path,
           String fnOut,
           boolean stdout,
           String fnErr,
           boolean stderr)

Create a Log object.

Parameters:

path - Path where log files are to be created and written to

fnOut - Base query log filename (before the ".CCYY-MM.log" portion)

stdout - Output to STDOUT in tandem with log file output (overrides to TRUE if fnOut is NULL)

fnErr - Base error log filename (before the ".CCYY-MM.log" portion)

stderr - Output to STDERR in tandem with err file output (overrides to TRUE if fnErr is NULL)

Log

public Log(String path,
           String fnOut,
           String fnErr)

Create a Log object.

Parameters:

path - Path where log files are to be created and written to

fnOut - Base query log filename (before the ".CCYY-MM.log" portion)

fnErr - Base error log filename (before the ".CCYY-MM.log" portion)

Method Detail

add

public Log.Entry add(String msg)

Add a normal log entry to the internal queue for logged output that is akin to sending to stdout.

Parameters:

msg - Log message (the portion after the timestamp)

add

public Log.Entry add(String pre,
                     String msg)

Add a normal log entry to the internal queue for logged output that is akin to sending to stdout.

Parameters:

pre - Log pre-amble (the portion before the timestamp)

msg - Log message (the portion after the timestamp)

err

public Log.Entry err(String msg)

Add an error log entry to the internal queue for logged output that is akin to sending to stderr.

Parameters:

msg - Log message (the portion after the timestamp)

err

public Log.Entry err(String pre,
                     String msg)

Add an error log entry to the internal queue for logged output that is akin to sending to stderr.

Parameters:

pre - Log pre-amble (the portion before the timestamp)

msg - Log message (the portion after the timestamp)

run

public void run()

Background task.

Specified by:

run in interface Runnable

Overrides:

run in class Thread

toString

public String toString()

Provide debug-readable output version of this object.

Overrides:

toString in class Thread

Returns:

String Output that will be helpful for debugging