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查找在logback中配置的所有logback Appender。xml,即使未连接到任何记录器

logback logging java

vl4d1m1r4 · 技术社区 · 7 年前

我正在构建一个管理UI,用于管理日志记录器级别和更改附加器。我知道我可以找到使用以下代码添加到某个记录器的所有appender:

private Map<String, Appender<ILoggingEvent>> getAppendersMap() {
    LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();

    Map<String, Appender<ILoggingEvent>> appendersMap = new HashMap<>();
    for (Logger logger : loggerContext.getLoggerList()) {
      Iterator<Appender<ILoggingEvent>> appenderIterator = logger.iteratorForAppenders();
      while (appenderIterator.hasNext()) {
        Appender<ILoggingEvent> appender = appenderIterator.next();
        if (!appendersMap.containsKey(appender.getName())) {
          appendersMap.put(appender.getName(), appender);
        }
      }
    }

    return appendersMap;
}

logback.xml 例如:

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false" scan="true" scanPeriod="10 minutes">

  <appender name="writeToConsole" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>
        %date{yyyy-MM-dd;HH:mm:ss.SSS} %-11p: %40.40c: %X{tablist}%m %n
      </pattern>
    </encoder>
  </appender>

  <appender name="NOPAppender" class="ch.qos.logback.core.helpers.NOPAppender" />

  <root>
    <level value="INFO"/>
    <appender-ref ref="writeToConsole"/>
  </root>

</configuration>

NOPAppender 是连接到任何记录器的a及其方法 getAppendersMap() 没有找到它

2 回复 | 直到 7 年前

glytching 7 年前

当从外部文件(logback.xml、logback-test.xml、logback.groovy等)配置自身时,logback会像这样遍历配置(这是它所做操作的简化版本):

查找任何附加器
APPENDER_BAG 在里面 InterpretationContext.objectMap
对于每个 appender-ref (存在于记录器定义中)在此中查找引用的appender(按名称) APPENDER\u袋

您可以使用appender关联定义显式记录器: <logger name="com.x.y" level="INFO"><appender-ref ref="STDOUT"/></logger> 或者使用 <root/> <root level="INFO"><appender-ref ref="STDOUT"/></root> .

因此,不与任何记录器关联的附加器仅在配置时已知,一旦 LoggerContext APPENDER\u袋 getAppendersMap() 找不到您的 NOOPAppender

我希望在应用程序运行时的某个时候使用。为了做到这一点,您必须在最初,但没有op实现。这是您在问题中已经在做的事情,但您只需要添加您的 NOPAppender 到根上下文。

<root level="INFO">
    <appender-ref ref="STDOUT"/>
    <appender-ref ref="NOPAppender"/>
</root>

这对正在运行的系统没有影响,因为appender是no op,但在 LoggerContext 当然,如果您想启用它,您可以对其进行管理,那么必须通过编程将appender类的选择更改为非no-op类。

LoggerContext 当你需要的时候。

Dharman GPuri 3 年前

import java.net.URL;
import java.util.HashMap;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.joran.JoranConfigurator;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.classic.util.ContextInitializer;
import ch.qos.logback.core.Appender;
import ch.qos.logback.core.joran.action.ActionConst;
import ch.qos.logback.core.joran.spi.InterpretationContext;
import ch.qos.logback.core.joran.spi.JoranException;

/**
 * Utility class for finding all configured logback appenders.
 */
public class LogbackAppenderFinder {

  private static final Logger LOGGER = LoggerFactory.getLogger(LogbackAppenderFinder.class);

  private LogbackAppenderFinder() {

  }

  /**
   * Tries to find all appenders from an xml config. The method works by trying to find the default logback config file 
   * names, can be further enhanced to include others, e.g. files supported by Spring Boot or custom files.
   *
   * @return Map of all the appenders configured with the XML file where the key is the appender name configured in
   * the xml file and the value is the appender itself.
   */
  public static Map<String, Appender<ILoggingEvent>> findAppendersFromXmlConfig() {
    try {
      LoggerContext dummyLoggerContext = new LoggerContext();
      ContextInitializer contextInitializer = new ContextInitializer(dummyLoggerContext);
      URL configurationFileUrl = contextInitializer.findURLOfDefaultConfigurationFile(true);
      if (configurationFileUrl != null && configurationFileUrl.toString().endsWith(".xml")) {
        JoranConfigurator configurator = new JoranConfigurator();
        configurator.setContext(dummyLoggerContext);
        configurator.doConfigure(configurationFileUrl);
        InterpretationContext interpretationContext = configurator.getInterpretationContext();
        Map<String, Object> objectMap = interpretationContext.getObjectMap();
        return (Map<String, Appender<ILoggingEvent>>) objectMap.get(ActionConst.APPENDER_BAG);
      } else {
        LOGGER.warn("Unable to find xml configuration file.");
      }
    } catch (JoranException e) {
      LOGGER.warn("Failed to parse logback configuration, check config file.");
    }
    return new HashMap<>();
  }

}