如何使用Java以編程方式配置Logback conversionRule？

Question

Logback conversionRule是否可以以編程方式配置Logback appender的相同方式進行編程配置（不編輯XML文件）？

Answer 1

//Here a simple example that works for me 
    package com; 
    import ch.qos.logback.classic.pattern.ClassicConverter; 
    import ch.qos.logback.classic.spi.ILoggingEvent; 

    public class MySampleConverter extends ClassicConverter { 
     long start = System.nanoTime(); 
     @Override 
     public String convert(ILoggingEvent event) { 
      long nowInNanos = System.nanoTime(); 
      return Long.toString(nowInNanos - start); 
     } 
    } 
    package com; 
    import java.util.HashMap; 
    import java.util.Map; 
    import org.slf4j.LoggerFactory; 
    import ch.qos.logback.classic.Level; 
    import ch.qos.logback.classic.Logger; 
    import ch.qos.logback.classic.LoggerContext; 
    import ch.qos.logback.classic.encoder.PatternLayoutEncoder; 
    import ch.qos.logback.classic.spi.ILoggingEvent; 
    import ch.qos.logback.core.ConsoleAppender; 
    import ch.qos.logback.core.CoreConstants; 
    import ch.qos.logback.core.FileAppender; 

    public class loggerutils { 
     static Logger foo = createLoggerFor("foo", "foo.log"); 
     public static void main(String[] args) { 
      foo.info("test"); 
     } 

     private static Logger createLoggerFor(String string, String file) { 
      String conversionWord = "nanoTime"; 
      String converterClass = "com.MySampleConverter"; 
      LoggerContext lc = (LoggerContext) LoggerFactory.getILoggerFactory(); 
      Map<String, String> ruleRegistry = (Map) lc 
        .getObject(CoreConstants.PATTERN_RULE_REGISTRY); 
      if (ruleRegistry == null) { 
       ruleRegistry = new HashMap<String, String>(); 
      } 
      lc.putObject(CoreConstants.PATTERN_RULE_REGISTRY, ruleRegistry); 
      ruleRegistry.put(conversionWord, converterClass); 

      PatternLayoutEncoder ple = new PatternLayoutEncoder(); 
      ple.setPattern("%-20nanoTime %-30(%d{HH:mm:ss.SSS} [%thread]) - %-15(%M) - %-5level -%logger{32} - %msg%n "); 

      ple.setContext(lc); 
      ple.start(); 
      FileAppender<ILoggingEvent> fileAppender = new FileAppender<ILoggingEvent>(); 
      fileAppender.setFile(file); 
      fileAppender.setEncoder(ple); 
      fileAppender.setContext(lc); 
      fileAppender.start(); 

      ConsoleAppender<ILoggingEvent> consoleAppender = new ConsoleAppender<ILoggingEvent>(); 
      consoleAppender.setEncoder(ple); 
      consoleAppender.setContext(lc); 
      consoleAppender.start(); 

      Logger logger = (Logger) LoggerFactory.getLogger(string); 
      logger.addAppender(fileAppender); 
      logger.setLevel(Level.DEBUG); 
      logger.setAdditive(false); /* set to true if root should log too */ 
      logger.addAppender(consoleAppender); 
      logger.setLevel(Level.DEBUG); 
      logger.setAdditive(false); 
      return logger; 
     } 
    }