How to set the contextName of a logger in Logback? - configuration

Question

Is there a way to set programmatically the contextName of a Logger in LogBack? I could then use the contextName to distinguish different instances of my Service class.
I see that we can set the contextName in the logback.xml, but this file is static in my project while the configuration of my application can change depending where my application is run from.
I'm searching a way to create dynamically contextNames and associate them to different instances of loggers.

Answer 1

The logback API can be called to implement the above functions, but not with dynamic contextNames. The following simple example
LoggerBuilder.java
import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
import ch.qos.logback.core.ConsoleAppender;
import org.slf4j.LoggerFactory;
import java.util.HashMap;
import java.util.Map;
public class LoggerBuilder {
private static final Map<String,Logger> container = new HashMap<>();
private static final LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();
public Logger getLogger(String name) {
Logger logger = container.get(name);
return logger;
}
public void buildLogger(String name,String pattern) {
Logger logger = context.getLogger(name);
logger.setAdditive(false);
PatternLayoutEncoder encoder = new PatternLayoutEncoder();
encoder.setContext(context);
encoder.setPattern(pattern);
encoder.start();
ConsoleAppender consoleAppender = new ConsoleAppender();
consoleAppender.setContext(context);
consoleAppender.setEncoder(encoder);
consoleAppender.start();
logger.addAppender(consoleAppender);
container.put(name,logger);
}
}
Test.java
import org.slf4j.Logger;
public class Test {
public static void main(String[] args) throws Exception {
LoggerBuilder loggerBuilder = new LoggerBuilder();
loggerBuilder.buildLogger("logger","%d %p (%file:%line\\)- %msg%n");
loggerBuilder.buildLogger("logger2","%d %p (%file:%line\\)%n");
Logger logger = loggerBuilder.getLogger("logger");
Logger logger2 = loggerBuilder.getLogger("logger2");
logger.info("1111");
logger2.info("2222");
}
}