"指定 log4j 日期的时区"

Question

Is it possible to specify the time zone that log4j will use? I need the dates in the log file to be a different time zone than the application's. log4j's PatternLayout<\/code> uses SimpleDateFormat<\/code> . Unfortunately there doesn't appear to be a way to control SimpleDateFormat<\/code> 's time zone via the pattern string ( DateFormat<\/code> has setTimeZone<\/code> method but that doesn't help).

Answer 1

If you use the Log4J extras JAR file on your classpath, the EnhancedPatternLayout class supports this configuration option. See the Javadoc at this link . It's handled as part of the %d pattern component like this:

log4j.appender.stdout.layout.ConversionPattern=%d{}{America/New_York} %p [%c] - %m%n

You can download the extras package here .

Answer 2

My Case... must change the patternLayout to EnhancedPatternLayout. (log4j-1.2.17.jar)

log4j.appender.logfile.layout=org.apache.log4j. EnhancedPatternLayout log4j.appender.logfile.layout.ConversionPattern=[%d{ISO8601}{GMT+9}]%-5p - %m%n

Answer 3

The log pattern above has right idea but not fully correct (you don't get any timestamp in log).
Use this pattern for sure:
%d{ISO8601}{America/New_York} %p [%c] - %m%n
or
%d{ISO8601}{GMT-5} %p [%c] - %m%n

Answer 4

It is preferable to use something like {America/New_York} rather than {GMT-5} because by specifying a timezone an automatic adjustment will be made if daylight savings is operational. Specifying something like GMT-5 will simply adjust the GMT time zone by the specified amount of hours.

Answer 5

Also if you whant to dinamicaly obtein the default time zone, you can extend EnhancedPatternLayout and overwrite the method "setConversionPattern" like this:

@Override
public void setConversionPattern(String conversionPattern) {
    String defaultTimeZoneId = TimeZone.getDefault().getID();
    String conversionPatternModif = conversionPattern.replaceAll(
        "\\%d\\{([^\\{\\}]*)\\}([ ]*[^\\{]*)", 
        "%d{$1}{"+defaultTimeZoneId+"}$2");

    super.setConversionPattern(conversionPatternModif);
}

Answer 6

Just append the timezone surrounded by curly braces to %d in your date pattern<\/a> .