java 是否可以在log4j中为stacktrace的每一行添加前缀?

lg40wkob  于 2022-11-27  发布在  Java
关注(0)|答案(5)|浏览(107)

当你写

logger.error("message", exception);

log4j生成消息和完整的堆栈跟踪:

Aug  9 06:26:13 10.175.60.14 myPrefix: [error] [TP-Processor114] [my.class.Name] message : exception
at fatherOfException
at fatherof_fatherOfException
at fatherof_fatherof_fatherOfException
...

我的转换模式是

log4j.appender.syslog.layout.ConversionPattern=myPrefix: [%p] [%t] [%c] [%x] - %m%n

因此,是否可以在每行前面加上myPrefix,如下所示:

Aug  9 06:26:13 10.175.60.14 myPrefix: [error] [TP-Processor114] [my.class.Name] message : exception
myPrefix    at fatherOfException
myPrefix    at fatherof_fatherOfException
myPrefix    at fatherof_fatherof_fatherOfException
    ...

当我在myPrefix上grep我的日志时,我看不到堆栈跟踪。我们有许多不同的前缀(每个模块一个)
先谢谢你。

dly7yett

dly7yett1#

请参考Alex的答案,因为它更清晰。

您可以编写自己的org.apache.log4j.spi.ThrowableRenderer实现:
http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/spi/ThrowableRenderer.html
然后,编辑log4j配置:
log4j.throwableRenderer=* 您的自定义类名 *
ThrowableRenderer返回一个String数组。代码如下:

String prefix = "myPrefix"; // Or some constant

List<String> l = new LinkedList<String>();
l.add(String.format("%s %s: %s", prefix, t.getClass().getName(), t.getMessage()));

for (StackTraceElement ste: t.getStackTrace()){
    l.add(String.format("%s %s", prefix, ste.toString()));
}

return (String[]) l.toArray();

另一个想法是将Throwable打印到PrintWriter中,PrintWriter Package 写入内存的一些Writer,然后重新迭代由line.separator分隔的字符串,将每一行添加到列表中:

StringWriter sw = new StringWriter();
t.printStackTrace(new PrintWriter(sw));

List<String> l = new LinkedList<String>();
for (String s: sw.toString().split(System.lineSeparator())) {
    l.add(String.format("%s %s", prefix, s));
}

return (String[]) l.toArray();
8oomwypt

8oomwypt2#

子类ThrowableRenderer,例如:

import org.apache.log4j.DefaultThrowableRenderer;
import org.apache.log4j.spi.ThrowableRenderer;

public class LogThrowableRenderer implements ThrowableRenderer {

    DefaultThrowableRenderer def = new DefaultThrowableRenderer();

    @Override
    public String[] doRender(Throwable t) {
        String[] temp = def.doRender(t);
        for (int i = 0; i < temp.length; i++) {
            temp[i] = "myPrefix "+temp[i];
        }
        return temp;
    }

}

添加到您的log4j.properties

log4j.throwableRenderer=whatever.package.LogThrowableRenderer

在添加前缀之前,它使用现有的DefaultThrowableRenderer以熟悉的方式呈现堆栈跟踪,因此它将包括Throwable类、消息和原因。

cbjzeqam

cbjzeqam3#

使用log4j2,您可以通过将separator指定为换行符,后跟前缀,为堆栈跟踪的每一个新行添加前缀:

%xThrowable{separator(\nmyPrefix)}%n

同样,您也可以在每个多行消息的每个新行中添加前缀:

%replace{%m}{[\r\n]+}{\nmyPrefix}

例如,要向每个多行日志和堆栈跟踪行添加空格前缀:

appender.rolling.layout.pattern = %d [%t] %-5p %c %L - %replace{%m}{[\r\n]+}{\n }%xThrowable{separator(\n )}%n

请注意,您要将%xThrowable位放在%m之后。

9wbgstp7

9wbgstp74#

编写一个 Package 函数来为您执行此操作。

private void writeToLogs(String message, Exception excp) {
    logger.error("myPrefix\t" + message, excp);
}
9rnv2umw

9rnv2umw5#

这是我找到并使用的一个回登录解决方案。目前的API不允许为堆栈跟踪的每一行添加前缀。对于其他行,我已经有了一个带跟踪ID的模式。所以我不得不使用它。所以我所做的是
1.我创建了一个CustomLayout扩展了LayoutBase
1.在doLayout方法中,您可以检查事件上是否有TrowableProxy,并从中解析每一行并添加前缀。我只是检查该行上是否有我的跟踪ID,如果没有,我只是附加了它。
下面是代码

public class MyLayout extends LayoutBase<ILoggingEvent> {

    private PatternLayout pattern = null;
    private String thePattern;

   @Override
    public String doLayout(ILoggingEvent event) {
        if (!pattern.isStarted()) {
            pattern.setPattern(thePattern);
            pattern.start();
        }

        String patternLayoutResult = pattern.doLayout(event);
        StringBuilder sb = new StringBuilder();

        String trackingId = MDC.get(TRACKING_ID);
        if (trackingId != null) {
            for (String line : patternLayoutResult.split(LINE_SEPARATOR)) {
                if (!line.contains(trackingId)) {
                    sb.append("Exception [");
                    sb.append(TRACKING_ID);
                    sb.append(":");
                    sb.append(trackingId);
                    sb.append("] ");

                }
                sb.append(line);
                sb.append(LINE_SEPARATOR);
            }

            return sb.toString();
        }

        return patternLayoutResult;
    }

在logback.xml中

<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
            <layout class="mypackage.CustomLoggingLayout">
                <thePattern>%d{dd.MM.yyyy HH:mm:ss} %-5p [trackingId:%X{trackingId}] %c{1}:%L - %m%n</thePattern>
                <Pattern></Pattern>
            </layout>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

现在,stackTrace看起来如下所示:

Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at org.glassfish.jersey.jdkhttp.JdkHttpHandlerContainer.handle(JdkHttpHandlerContainer.java:161)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:79)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:83)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:82)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(ServerImpl.java:700)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:79)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at sun.net.httpserver.ServerImpl$Exchange.run(ServerImpl.java:672)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
Exception [trackingId:d3746a12a86e46f991a338b4317045f5] at java.lang.Thread.run(Thread.java:748)

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