Java Log4j2 转换器类别插件添加多个自定义字段到日志

Question

我尝试了 Extending Log4j2 中的示例和 Create Custom Pattern using log4j2 in java现在我想向日志添加两个字段。我需要做哪些改变才能得到这个？

Answer 1

请参阅本手册 https://logging.apache.org/log4j/log4j-2.2/manual/plugins.html#Converters

如果您想要多个字段，例如时间和名称，您可以创建两个单独的转换器来向日志提供该数据。

例如您有MyNamePatternConverter，这里我们可以提供别名whatIsMyName和myName。在日志模式中，我们可以使用其中任何一个。

@Plugin(name="MyNamePatternConverter", category = PatternConverter.CATEGORY)
@ConverterKeys(value = {"whatIsMyName", "myName"})
public class MyNameConverter extends LogEventPatternConverter {

    protected MyNameConverter(String name, String style) {
        super(name, style);
    }

    public static MyNameConverter newInstance(String[] options) {
        return new MyNameConverter("My name Converter", "name");
    }

    public void format(LogEvent event, StringBuilder toAppendTo) {
        toAppendTo.append("Yuriy");
    }
}

和TimePatternConverter

@Plugin(name = "TimePatternConverter", category = PatternConverter.CATEGORY)
@ConverterKeys(value = {"timeIsNow", "timeNow", "now"})
public class TimeConverter extends LogEventPatternConverter {
    protected TimeConverter(String name, String style) {
        super(name, style);
    }

    public static TimeConverter newInstance(String[] options) {
        return new TimeConverter("Time Converter", "now");
    }

    public void format(LogEvent logEvent, StringBuilder toAppendTo) {
        toAppendTo.append(new SimpleDateFormat("HH:mm").format(new Date()));
    }
}

我们将把它们两个放在名为转换器的单独包中。

<?xml version="1.0" encoding="UTF-8"?>
<Configuration xmlns="http://logging.apache.org/log4j/2.0/config"
               status="OFF" packages="converters">
    <Appenders>
        <Console name="STDOUT" target="SYSTEM_OUT">
            <PatternLayout pattern="Time is now %timeIsNow and my name is %whatIsMyName, %m%n"/>
        </Console>
    </Appenders>
    <Loggers>
        <Logger name="org.apache.log4j.xml" level="all" />
        <Root level="all">
            <AppenderRef ref="STDOUT" />
        </Root>
    </Loggers>
</Configuration>

提供log4j2.xml。

并创建一个示例主类来测试它。

public class Main {
    private static final Logger logger = LogManager.getLogger(ResolverUtil.Test.class);
    public static void main(String[] args) {
        logger.info("Hello log4j2");
        logger.debug("This is debug message");
    }
}

这将产生这样的输出:

Time is now 20:40 and my name is Yuriy, Hello log4j2
Time is now 20:40 and my name is Yuriy, This is debug message