如何为log4j设置单独的日志记录流? [英] How can I set up separate streams of logging for log4j?

问题描述

说我有一个像这样的课程:

Say I have a class like this:

public class MyClass
{

    private Logger log = LoggerFactory.getLogger(MyClass.class); //org.slf4j.LoggerFactory

    public void foo(Params p)
    {
         log.info("Foo params: " + p);
         long t1 = System.currentTimeMillis();

         Result r = someMethod(p);

         long t2 = System.currentTimeMillis();
         log.info("Foo result: " + r)
         log.info("Foo time taken: + (t2-t1)/1000); 
    }

}

现在，要打印此信息，我希望能够打开和关闭不同类型的信息(参数，结果，花费的时间).

Now when it comes to printing this info, I want to be able to turn on and off the different types of info (Parameters, Results, Time Taken).

使用日志记录级别进行区分的问题在于，更精细的粒度级别还包含了更粗糙的级别.

The problem with using logging levels to differentiate, is that the finer levels of granularity also encompass the coarser levels.

如何轻松设置?

推荐答案

您可以通过创建自定义日志记录类来设置不同的日志记录行为.

You set different logging behaviour by creating custom logging classes.

这是我的解决方法:

public abstract class AbstractLogger {

    protected Logger log;
    protected Class callingClass;
    public AbstractLogger(Class c)
    {
        this.log = LoggerFactory.getLogger(this.getClass());
        this.callingClass = c;
    }

    public void log(String s)
    {
        log.debug(this.callingClass + " :" + s);
    }

}

public class LoggerOne extends AbstractLogger {    

    public LoggerOne(Class c) {
        super(c);           
    }

}

public class LoggerTwo extends AbstractLogger {   

    public LoggerTwo(Class c) {
        super(c);           
    }    

}

public class LoggerThree extends AbstractLogger {    

    public LoggerThree(Class c) {
        super(c);           
    }    
}

Log4j.properties中的设置

Setup in Log4j.properties

#Define custom levels by package
#set to ERROR to turn them off
log4j.logger.org.myproject.loggers.LoggerOne=ERROR
log4j.logger.org.myproject.loggers.LoggerTwo=DEBUG
log4j.logger.org.myproject.loggers.LoggerThree=DEBUG

使用这些记录器时:

要使用这些记录器，请执行以下操作:

To use these logger:

 public class MyMain {


    // private Logger log = LoggerFactory.getLogger(MyMain.class);

     private AbstractLogger l1= new LoggerOne(this.getClass());
     private AbstractLogger l2= new LoggerTwo(this.getClass());
     private AbstractLogger l3= new LoggerThree(this.getClass());


    public void run()
    {

            l1.log("log 1");

             long t1 = System.currentTimeMillis();

             try {
                    Thread.sleep(1000);                 //1000 milliseconds is one second.
                } catch(InterruptedException ex) {
                    Thread.currentThread().interrupt();
                }

             long t2 = System.currentTimeMillis();
             l2.log("log 2");
             l3.log("Foo time taken:" + (t2-t1)/1000); 

    }

    public static void main(String[] args) {

        MyMain me = new MyMain();
        me.run();

    }

}

日志输出:

12:27:29 DEBUG LoggerTwo:18 - class maventestspace.MyMain :log 2
12:27:29 DEBUG LoggerThree:18 - class maventestspace.MyMain :Foo time taken:1

请注意，由于在属性文件中将LoggerOne设置为ERROR，因此LoggerOne无法打印.

Note that LoggerOne isn't printing, because it is set to ERROR in the properties file.

要重定向这些单独的日志文件，您需要设置新的附加程序和记录器.

To redirect these seperate log files, you need to set up new appenders and loggers.

log4j.logger.org.myproject.loggers.LoggerOne=DEBUG, file1, stdout
log4j.logger.org.myproject.loggers.LoggerTwo=DEBUG, file2, stdout
log4j.logger.org.myproject.loggers.LoggerThree=DEBUG, file3, stdout


# Direct log messages to a log file
log4j.appender.file1=org.apache.log4j.RollingFileAppender
#log4j.appender.TextProcessor.Threshold=debug
log4j.appender.file1.File=E:\\logs\\log1.txt
log4j.appender.file1.MaxFileSize=10MB
log4j.appender.file1.MaxBackupIndex=1
log4j.appender.file1.layout=org.apache.log4j.PatternLayout
log4j.appender.file1.layout.ConversionPattern=%d{HH:mm:ss} %-5p %c{1}:%L - %m%n




# Direct log messages to a log file
log4j.appender.file2=org.apache.log4j.RollingFileAppender
#log4j.appender.TextProcessor.Threshold=debug
log4j.appender.file2.File=E:\\logs\\log2.txt
log4j.appender.file2.MaxFileSize=10MB
log4j.appender.file2.MaxBackupIndex=1
log4j.appender.file2.layout=org.apache.log4j.PatternLayout
log4j.appender.file2.layout.ConversionPattern=%d{HH:mm:ss} %-5p %c{1}:%L - %m%n



# Direct log messages to a log file
log4j.appender.file3=org.apache.log4j.RollingFileAppender
#log4j.appender.TextProcessor.Threshold=debug
log4j.appender.file3.File=E:\\logs\\log3.txt
log4j.appender.file3.MaxFileSize=10MB
log4j.appender.file3.MaxBackupIndex=1
log4j.appender.file3.layout=org.apache.log4j.PatternLayout
log4j.appender.file3.layout.ConversionPattern=%d{HH:mm:ss} %-5p %c{1}:%L - %m%n

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