如何为log4j设置单独的日志记录流？

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。

这是我的解决方案：

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);    }    }

在Log4j.properties中设置

#Define custom levels by package#set to ERROR to turn them offlog4j.logger.org.myproject.loggers.LoggerOne=ERRORlog4j.logger.org.myproject.loggers.LoggerTwo=DEBUGlog4j.logger.org.myproject.loggers.LoggerThree=DEBUG

使用这些记录器时：

要使用这些记录器：

 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 212:27:29 DEBUG LoggerThree:18 - class maventestspace.MyMain :Foo time taken:1

请注意，LoggerOne无法打印，因为在属性文件中将其设置为ERROR。

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。

log4j.logger.org.myproject.loggers.LoggerOne=DEBUG, file1, stdoutlog4j.logger.org.myproject.loggers.LoggerTwo=DEBUG, file2, stdoutlog4j.logger.org.myproject.loggers.LoggerThree=DEBUG, file3, stdout# Direct log messages to a log filelog4j.appender.file1=org.apache.log4j.RollingFileAppender#log4j.appender.TextProcessor.Threshold=debuglog4j.appender.file1.File=E:\logs\log1.txtlog4j.appender.file1.MaxFileSize=10MBlog4j.appender.file1.MaxBackupIndex=1log4j.appender.file1.layout=org.apache.log4j.PatternLayoutlog4j.appender.file1.layout.ConversionPattern=%d{HH:mm:ss} %-5p %c{1}:%L - %m%n# Direct log messages to a log filelog4j.appender.file2=org.apache.log4j.RollingFileAppender#log4j.appender.TextProcessor.Threshold=debuglog4j.appender.file2.File=E:\logs\log2.txtlog4j.appender.file2.MaxFileSize=10MBlog4j.appender.file2.MaxBackupIndex=1log4j.appender.file2.layout=org.apache.log4j.PatternLayoutlog4j.appender.file2.layout.ConversionPattern=%d{HH:mm:ss} %-5p %c{1}:%L - %m%n# Direct log messages to a log filelog4j.appender.file3=org.apache.log4j.RollingFileAppender#log4j.appender.TextProcessor.Threshold=debuglog4j.appender.file3.File=E:\logs\log3.txtlog4j.appender.file3.MaxFileSize=10MBlog4j.appender.file3.MaxBackupIndex=1log4j.appender.file3.layout=org.apache.log4j.PatternLayoutlog4j.appender.file3.layout.ConversionPattern=%d{HH:mm:ss} %-5p %c{1}:%L - %m%n