Question

我正在通过MDC插入一些变量，但是如果在varback模式中没有使用此var，我想记录一个WARN。有谁知道如何在java代码中检索回归模式？ STH。像这样：

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

...
Logger LOG = LoggerFactory.getLogger(MyTestClass.class);
...

MDC.put("id","thisIsATestId");
String pattern = LOG.getLogbackPattern();
checkPatternAndWarnIfMissingVar(pattern,"id");
...

Answer 1

这有点难看，这可能表示我们并不打算这样做，但似乎有效：

// Get some internal contexts
ch.qos.logback.classic.Logger logger = (ch.qos.logback.classic.Logger)
        LoggerFactory.getLogger(ch.qos.logback.classic.Logger.ROOT_LOGGER_NAME);

// Get the current pattern in the appender.
OutputStreamAppender<ILoggingEvent> consoleapp = 
    (OutputStreamAppender<ILoggingEvent>) logger.getAppender("console");

// Now check the pattern
PatternLayoutEncoder encoder = (PatternLayoutEncoder) consoleapp.getEncoder();
String pattern = encoder.getPattern();
checkPatternAndWarnIfMissingVar(pattern,"id");

请注意，这假设一个名为＆＃34; console＆＃34;的追加器。 appender列表取决于您的配置，可以使用以下方法检索：

Iterator<Appender<ILoggingEvent>> it = logger.iteratorForAppenders();
while (it.hasNext()) {
    Appender<ILoggingEvent> app = it.next();
    System.out.println( app.getName() );
}

Answer 2

更新 Henrik 的答案，我让它像这样工作：

import ch.qos.logback.classic.Logger;
import org.slf4j.LoggerFactory;
import ch.qos.logback.core.OutputStreamAppender;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.classic.encoder.PatternLayoutEncoder;

private String getPattern() {
    Logger logger = (Logger) LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME);

    OutputStreamAppender<ILoggingEvent> consoleAppender =
            (OutputStreamAppender<ILoggingEvent>) logger.getAppender("CONSOLE");

    PatternLayoutEncoder encoder = (PatternLayoutEncoder) consoleAppender.getEncoder();
    return encoder.getPattern();
}

在java代码中获取Logback模式

2 个答案: