если вы используете log4j, вы можете добавить файл config.properties
к своим ресурсам:
# Root logger option
log4j.rootLogger=INFO, file, stdout
# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
# this is the ouput file path and name
log4j.appender.file.File=filename.log
log4j.appender.file.MaxFileSize=10MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
Тогда вы можете использовать вот так:
import org.apache.log4j.Logger;
public class A {
Logger log= Logger.getLogger(A.class);
someMethod(){
log.debug("inside some method in class A");
}
public class B {
Logger log= Logger.getLogger(B.class);
someOtherMethod(){
log.debug("inside some other method in class B");
}
}