How to modify SLF4J log output

Question

how can I supress the classnames in sl4j?

public class LogManager {
  static Logger logger = LoggerFactory.getLogger(classname);

  static void log(String sender, String msg) {
    logger.info(sender + " - " + msg);       
  }
}

The output of this its something like this:

2018-05-23 16:15:41,000 [ 196598]   WARN - [classname] - [sender] - [msg]

how can I remove the classname?

Other questions: Is there a way to remove the loglevel? What is the number "[ 196598]" in the string and how can it be removed?

Answer 1

If you are using Log4j you can use the org.apache.log4j.PatternLayout to format the logging information.

conversionPattern Sets the conversion pattern. Default is %r [%t] %p %c %x - %m%n .

c - Used to output the category of the logging event.

For example, for the category name "abc" the pattern %c{2} will output "bc".

C - Used to output the fully qualified class name of the caller issuing the logging request.

For example, for the class name "org.apache.xyz.SomeClass" , the pattern %C{1} will output "SomeClass" .

Define the layout for file appender log4j.appender.FILE.layout=org.apache.log4j.PatternLayout log4j.appender.FILE.layout.ConversionPattern=%d{yyyy-MM-dd}-%t-%x-%-5p-%-C{1}:%m%n

This is how you need to provide in the config file of log4j.