log4j-1.2.9自定义Appender

import org.apache.log4j.spi.LoggingEvent;






public class SpecialAppender extends org.apache.log4j.RollingFileAppender ...{


private String prefix = "";






public SpecialAppender() ...{


addFilter(new MyFilter());


}






private class MyFilter extends org.apache.log4j.spi.Filter ...{




public MyFilter() ...{


}




// @Override




public int decide(LoggingEvent loggingEvent) ...{




if (loggingEvent == null || loggingEvent.getMessage() == null) ...{


return super.DENY;


}




if (loggingEvent.getMessage().toString().startsWith(prefix)) ...{


return super.ACCEPT;


}


return super.DENY;


}


}






public String getPrefix() ...{


return prefix;


}






public void setPrefix(String prefix) ...{


this.prefix = prefix;


}




}

过滤器 MyFilter 过滤以prefix(在log4j.properties中配置的)为前缀的Message. 如果MESSAGE以prefix为前缀则打印log.