public class SimpleFormatter extends Formatter
LogRecord in a human readable
format. The summary will typically be 1 or 2 lines.
Configuration:
The SimpleFormatter is initialized with the
format string
specified in the java.util.logging.SimpleFormatter.format
property to format the log messages.
This property can be defined
in the LogManager#getProperty
configuration file
or as a system property. If this property is set in both
the logging properties and system properties,
the format string specified in the system property will be used.
If this property is not defined or the given format string
is illegal,
the default format is implementation-specific.
Formatter| 构造器 | 说明 |
|---|---|
SimpleFormatter() |
public String format(LogRecord record)
The formatting can be customized by specifying the
format string
in the
java.util.logging.SimpleFormatter.format property.
The given LogRecord will be formatted as if by calling:
String#format(format, date, source, logger, level, message, thrown);
where the arguments are:format - the java.util.Formatter format string specified in the
java.util.logging.SimpleFormatter.format property
or the default format.date - a Date object representing
LogRecord#getMillis of the log record.source - a string representing the caller, if available;
otherwise, the logger's name.logger - the logger's name.level - the Level#getLocalizedName.message - the formatted log message
returned from the Formatter#formatMessage(LogRecord)
method. It uses java.text
formatting and does not use the java.util.Formatter
format argument.thrown - a string representing
the LogRecord#getThrown
associated with the log record and its backtrace
beginning with a newline character, if any;
otherwise, an empty string.Some example formats:
java.util.logging.SimpleFormatter.format="%4$s: %5$s [%1$tc]%n"
This prints 1 line with the log level (4$),
the log message (5$) and the timestamp (1$) in
a square bracket.
WARNING: warning message [Tue Mar 22 13:11:31 PDT 2011]
java.util.logging.SimpleFormatter.format="%1$tc %2$s%n%4$s: %5$s%6$s%n"
This prints 2 lines where the first line includes
the timestamp (1$) and the source (2$);
the second line includes the log level (4$) and
the log message (5$) followed with the throwable
and its backtrace (6$), if any:
Tue Mar 22 13:11:31 PDT 2011 MyClass fatal
SEVERE: several message with an exception
java.lang.IllegalArgumentException: invalid argument
at MyClass.mash(MyClass.java:9)
at MyClass.crunch(MyClass.java:6)
at MyClass.main(MyClass.java:3)
java.util.logging.SimpleFormatter.format="%1$tb %1$td, %1$tY %1$tl:%1$tM:%1$tS %1$Tp %2$s%n%4$s: %5$s%n"
This prints 2 lines similar to the example above with a different date/time formatting and does not print the throwable and its backtrace:
Mar 22, 2011 1:11:31 PM MyClass fatal
SEVERE: several message with an exception
This method can also be overridden in a subclass.
It is recommended to use the Formatter#formatMessage
convenience method to localize and format the message field.