Log4j2 JSONLayout时间戳模式

Question

显然，log4j2中的JSONLayout没有时间戳模式支持。通常，它只有JSON格式选项，但没有patter选项。

{
  "configuration": {
    "name": "logggg",
    "packages" : "logger.savemyjob",
    "appenders": {
      "RollingFile": {
        "name": "rollingStone",
        "fileName": "async_rolled.log",
        "filePattern": "async_rolled-%d{MM-dd-yy-HH-mm-ss}-%i.log.gz",
        "immediateFlush" : false,
         "JSONLayout": {
            "complete": true,
            "compact": false,
            "eventEol": true
         },
        "SizeBasedTriggeringPolicy": {
          "size": "10 MB"
        },
        "DefaultRolloverStrategy": {
          "max": "10"
        }
      }
    },
    "loggers": {
      "root": {
        "level": "debug",
        "appender-ref": {
          "ref": "rollingStone"
        }
      }
    }
  }
}

日志示例,

{
  "timeMillis" : 1482231551081,
  "thread" : "main",
  "level" : "debug",
  "endOfBatch" : false,
  "threadId" : 1,
  "threadPriority" : 5, 
  "message" : "log4j might suck"
}

当我查看他们的API时，看起来太冗长了，没有看到添加时间戳字段的更简单的方法。

@Plugin(name = "JsonLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
public final class JsonLayout extends AbstractJacksonLayout {

protected JsonLayout(final Configuration config, final boolean locationInfo, final boolean properties,
            final boolean encodeThreadContextAsList,
            final boolean complete, final boolean compact, final boolean eventEol, final String headerPattern,
            final String footerPattern, final Charset charset) {
        super(config, new JacksonFactory.JSON(encodeThreadContextAsList).newWriter(locationInfo, properties, compact),
                charset, compact, complete, eventEol,
                PatternLayout.createSerializer(config, null, headerPattern, DEFAULT_HEADER, null, false, false),
                PatternLayout.createSerializer(config, null, footerPattern, DEFAULT_FOOTER, null, false, false));
    }

}

public interface LogEvent extends Serializable {

    @Deprecated
    Map<String, String> getContextMap();

    ReadOnlyStringMap getContextData();

    ThreadContext.ContextStack getContextStack();

    String getLoggerFqcn();

    Level getLevel();

    String getLoggerName();

    Marker getMarker();

    Message getMessage();

    long getTimeMillis();

    StackTraceElement getSource();

    String getThreadName();

    long getThreadId();

    int getThreadPriority();

    Throwable getThrown();

    ThrowableProxy getThrownProxy();

    boolean isEndOfBatch();

    boolean isIncludeLocation();

    void setEndOfBatch(boolean endOfBatch);

    void setIncludeLocation(boolean locationRequired);

    long getNanoTime();

    String getTimestamp();
}

public class MutableLogEvent implements LogEvent, ReusableMessage {

    public void initFrom(final LogEvent event) {

        SimpleDateFormat standardDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        this.timestamp = standardDateFormat.format(new Date(event.getTimeMillis()));
    }
}

我猜它可能会工作，尽管它打破了一些核心log4j-core测试。我基本上想知道以最小的变化添加额外的json字段的诀窍。

我很少看到其他类似JSONEventLayoutV1的impl，它似乎与性能非常好的log4j json api完全不同。

下面是我尝试重写logevent的失败尝试，https://github.com/prayagupd/sell-peace/blob/custom_timestamp/supply-peace/src/main/java/org/apache/logging/log4j/core/dnlogevent.java

问题越来越长，我基本上想知道重写log4j2 API时不要错过的重要内容。

Answer 1

如果这只是添加一个包含时间戳的新字段的问题，除了默认提供的timeMillis之外，为什么不尝试在新的自定义域上使用查找。

JsonLayout配置可能如下所示：

<JsonLayout>
    <KeyValuePair key="timestamp" value="$${date:yyyy-MM-dd'T'HH:mm:ss.SSSZ}" />
</JsonLayout>

$$是查找，date:后面的字符是java SimpleDateFormat可以接受的格式。