无法使用 log4j2 为不同的线程写入不同的日志

Question

我正在尝试为每个 Thread/ThreadGroup 将日志写入不同的文件。我的代码为每个线程创建不同的文件，但它将所有其他线程写入一个文件。

MainTest.java

public class MainTest {
    public static void main(String[] args) {
        ThreadGroup tg1 = new ThreadGroup("Group A");

        Thread t1 = new Thread(tg1, new LoggingTest(), "t1");
        t1.start();

        Thread t2 = new Thread(tg1, new LoggingTest(), "t2");
        t2.start();

        //
        Thread t3 = new Thread(new LoggingTest(),"t3");
        t3.start();
    }
}

LoggingTest.java

public class LoggingTest implements Runnable {
    private static final Logger logger      = LogManager.getLogger(LoggingTest.class);
    private static final String logFilePath = "/output/logs/";
    private static final String pattern     = "%d{dd MMM yyyy HH:mm:ss.SSS} (%F:%L) - %m%n";

    public void run() {
        Thread runner         = Thread.currentThread();
        
        LoggerContext context = (org.apache.logging.log4j.core.LoggerContext) LogManager.getContext(false);
        try {
            URL configFile    = LoggingTest.class.getResource("/log4j2.properties");
            context.setConfigLocation(configFile.toURI());
        }catch(Exception e) {
            e.printStackTrace();
        }
        
        LoggerContext ctx     = (LoggerContext) LogManager.getContext(false);
        FileAppender appender = null;
        try {
            appender = FileAppender
                    .newBuilder()
                    .setName("Name")
                    .setLayout(PatternLayout.newBuilder().withPattern(pattern).build())
                    .withFileName(logFilePath + runner.getName() + ".log")
                    .build();
        } catch (Exception e) {
            logger.error("error -> "+e);
        }
        
        if (appender != null) {
            if ( runner.getThreadGroup().getParent() != null )
            {
                appender.addFilter( new ThreadGroupFilter( runner.getThreadGroup() ) );
            }
            else
            {
                appender.addFilter( new ThreadFilter( runner ) );
            }
            appender.start();
            ctx.getRootLogger().addAppender(appender);
            ctx.updateLoggers();
        }

        logger.info("info msg");
        logger.debug("debug msg");
        logger.error("error msg");

        if ( appender != null ) {
            ctx.getRootLogger().removeAppender(appender);
            ctx.updateLoggers();
            appender.stop();
        }
    }
}

在这里，我为线程和线程组创建了几个过滤器类。但似乎这些无法正常工作。 ThreadGroupFilter.java

import org.apache.logging.log4j.core.Filter;  

public class ThreadGroupFilter implements Filter {
        
        private final ThreadGroup filterThreadGroup;
    
        public ThreadGroupFilter( ThreadGroup filterThreadGroup ) {
            this.filterThreadGroup = filterThreadGroup;
        }
    
        @Override
        public Result filter(LogEvent event) {
            if ( Thread.currentThread().getThreadGroup() != filterThreadGroup )
                return Filter.Result.DENY;
    
            return Filter.Result.NEUTRAL;
        }
    }

ThreadFilter.java

public class ThreadFilter implements Filter {
    private final Thread filterThread;

    public ThreadFilter( Thread filterThread ) {
        this.filterThread = filterThread;
    }
    
    @Override
    public Result filter(LogEvent event) {
        if ( Thread.currentThread() != filterThread )
            return Filter.Result.DENY;

        return Filter.Result.NEUTRAL;
    }
}

log4j2.properties

name=PropertiesConfig
property.basePath = ../logs

appenders = console

appender.console.type = Console
appender.console.name = consoleLogger
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = %5p [%c] [%t] (%F:%L) - %m%n

rootLogger.level = debug
rootLogger.appenderRefs = console
rootLogger.appenderRef.stdout.ref = consoleLogger

我希望每个 Thread/ThreadGroup 有多个日志文件。但是我最终得到了每个线程的多个日志文件，并且所有线程都记录到一个文件中。

提前致谢。

Answer 1

您的每个线程都调用 LoggerContext#setConfigLocation，这会导致重新配置 Log4j2。重新配置删除您以编程方式添加的所有附加程序。这就是为什么你最终只有一个附加程序。

请注意，您不需要编程配置每个线程都有不同的文件附加程序。您可以像 .

中那样使用 RoutingAppender

编辑：如果你真的想使用程序化配置（出于兼容性原因不鼓励这样做），你还需要为每个appender使用一个唯一的名称，否则它们将静默忽略（您使用的 Logger#addAppender 方法不是 public API 的一部分，请参见 javadoc，因此不会报告错误）。

Answer 2

将这段代码从 LoggingTest 移到 MainTest

LoggerContext context = (org.apache.logging.log4j.core.LoggerContext) LogManager.getContext(false);
try {
    URL configFile    = LoggingTest.class.getResource("/log4j2.properties");
    context.setConfigLocation(configFile.toURI());
}catch(Exception e) {
    e.printStackTrace();
}

并在 Appender 配置中进行了细微修改。

FileAppender appender = null;
String appenderName = (runner.getThreadGroup() != null) ? "appender_"+runner.getThreadGroup().getName() : "appender_"+runner.getName();
try {
    appender = FileAppender
            .newBuilder()
            .setName(appenderName)
            .setLayout(PatternLayout.newBuilder().withPattern(pattern).build())
            .withFileName(logFilePath + appenderName + ".log")
            .build();
} catch (Exception e) {
    logger.error("error -> "+e);
}

感谢解决方案Poitr P. Karwasz

无法使用 log4j2 为不同的线程写入不同的日志

unable to write into different logs for different threads using log4j2

java

multithreading

fileappender

log4j2