Package org.apache.juneau.commons.logging

Class LogRecord

java.lang.Object

java.util.logging.LogRecord

org.apache.juneau.commons.logging.LogRecord

All Implemented Interfaces:

Serializable

public class LogRecord
extends LogRecord

LogRecord that supports lazy message formatting.

This class extends java.util.logging.LogRecord and overrides getMessage() to use StringUtils.format(String, Object...) (printf-style "%s"/"%d") for lazy formatting. The message is only formatted when getMessage() is actually called.

Usage:

This class is used internally by RichLogger when logging formatted messages. The formatted message is only computed when the LogRecord's message is actually accessed (e.g., by a Handler or Formatter).

Formatting contract:

Juneau RichLogger patterns are printf-style (rendered here via StringUtils.format(String, Object...)). Because this override returns the already-substituted message, downstream Handlers and Formatters that call getMessage() see fully-rendered text and never re-apply formatting — so the printf-vs-MessageFormat choice is purely internal. The JDK's MessageFormat parameter contract of LogRecord only resurfaces if a record is serialized and consumed as a plain LogRecord by a non-Juneau handler; such a consumer would apply MessageFormat to the raw {0} pattern, so printf patterns are not intended for that scenario.

See Also:

• RichLogger
• StringUtils.format(String, Object...)
• LogRecord

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
LogRecord(String loggerName, Level level, String msg, Object[] parameters, Throwable throwable)	Constructor.
LogRecord(String loggerName, Level level, String msg, Object[] parameters, Throwable throwable, MessageGenerator generator)	Constructor.

Method Summary

Modifier and Type	Method	Description
String	formatted(String format)	Formats this log record as a string using the specified format pattern.
static String	formatted(LogRecord rec, String format)	Formats a JUL log record with the same placeholders as formatted(String).
String	getMessage()	Returns the log message, formatting it lazily if needed.

Methods inherited from class java.util.logging.LogRecord

getInstant, getLevel, getLoggerName, getLongThreadID, getMillis, getParameters, getResourceBundle, getResourceBundleName, getSequenceNumber, getSourceClassName, getSourceMethodName, getThreadID, getThrown, setInstant, setLevel, setLoggerName, setLongThreadID, setMessage, setMillis, setParameters, setResourceBundle, setResourceBundleName, setSequenceNumber, setSourceClassName, setSourceMethodName, setThreadID, setThrown

Methods inherited from class java.lang.Object

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

Constructor Details

LogRecord

public LogRecord(String loggerName,
 Level level,
 String msg,
 Object[] parameters,
 Throwable throwable)

Constructor.

Parameters:

loggerName - The logger name. Can be null.

level - The log level. Must not be null.

msg - The message pattern (will be used as-is if args is null or empty).

parameters - The format arguments, or null if none.

throwable - The throwable, or null if none.

LogRecord

public LogRecord(String loggerName,
 Level level,
 String msg,
 Object[] parameters,
 Throwable throwable,
 MessageGenerator generator)

Constructor.

Parameters:

loggerName - The logger name. Can be null.

level - The log level. Must not be null.

msg - The message pattern (will be used as-is if args is null or empty).

parameters - The format arguments, or null if none.

throwable - The throwable, or null if none.

generator - The message generator.

Method Details

getMessage

public String getMessage()

Returns the log message, formatting it lazily if needed.

If parameters were set via LogRecord.setParameters(Object[]), the message is formatted using StringUtils.format(String, Object...) on first access.

Overrides:

getMessage in class LogRecord

Returns:

The log message, formatted if parameters are present.

formatted

public String formatted(String format)

Formats this log record as a string using the specified format pattern.

Similar to how SimpleFormatter formats log records, this method allows you to specify a custom format string with placeholders that are replaced with actual values from the log record.

The format string supports both named placeholders (e.g., "{date}") and Formatter-style format specifiers (e.g., "%1$tc"). Named placeholders are replaced first, then the resulting string is formatted using Formatter with the following arguments:

1. date - The date/time as a Date object
2. logger - The logger name
3. level - The log level
4. message - The formatted log message
5. thrown - The throwable object (if any)

Named Placeholders:

• "{date}" - The date/time formatted using SimpleFormatter's default date format
• "{timestamp}" - The date/time formatted as ISO-8601 (yyyy-MM-dd'T'HH:mm:ss.SSSZ)
• "{logger}" - The logger name
• "{level}" - The log level name
• "{msg}" - The log message (formatted if parameters are present)
• "{thread}" - The thread ID
• "{threadid}" - The thread ID (alias for {thread})
• "{exception}" - The exception message (if thrown)
• "{thrown}" - The throwable object (if thrown)

Formatter-Style Format Specifiers:

You can use Formatter-style format specifiers directly in the format string. The arguments are passed in the same order as SimpleFormatter:

• "%1$s" or "%1$tc" - The date/time (argument 1)
• "%2$s" - The logger name (argument 2)
• "%3$s" - The log level (argument 3)
• "%4$s" - The log message (argument 4)
• "%5$s" - The throwable and its backtrace (argument 5)

For date/time formatting, you can use date/time conversion characters with argument 1:

• "%1$tc" - Complete date and time (e.g., "Tue Mar 22 13:11:31 PDT 2011")
• "%1$tb" - Month abbreviation (e.g., "Mar")
• "%1$td" - Day of month (01-31)
• "%1$tY" - Year (4 digits)
• "%1$tH" - Hour (00-23)
• "%1$tM" - Minute (00-59)
• "%1$tS" - Second (00-59)
• "%1$tL" - Milliseconds (000-999)
• "%1$tN" - Nanoseconds (000000000-999999999, since JDK 9)
• "%1$Tp" - AM/PM marker (uppercase)
• "%1$tp" - AM/PM marker (lowercase)

The format string can also contain "%n" for newlines.

Examples:

LogRecord record = new LogRecord(Level.INFO, "User {0} logged in", "John"); // Using named placeholders String formatted1 = record.formatted("[{timestamp} {level}] {msg}"); // Result: "[2025-01-22T07:42:45.123-0500 INFO] User John logged in" // Using Formatter-style specifiers String formatted2 = record.formatted("%3$s: %4$s [%1$tc]%n"); // Result: "INFO: User John logged in [Tue Jan 22 07:42:45 PST 2025]" // Mixed named placeholders and Formatter specifiers String formatted3 = record.formatted("%1$tb %1$td, %1$tY {level}: {msg}%n"); // Result: "Jan 22, 2025 INFO: User John logged in"

Parameters:

format - The format string with placeholders and/or Formatter-style format specifiers.

Returns:

The formatted string.

See Also:

• SimpleFormatter
• Formatter

formatted

public static String formatted(LogRecord rec,
 String format)

Formats a JUL log record with the same placeholders as formatted(String).

Parameters:

rec - The record to format.

format - The format string.

Returns:

The formatted string.