How to change root logging level programmatically for logback

Question

I have the following logback.xml file:

Answer 1

Here's a controller

@RestController
@RequestMapping("/loggers")
public class LoggerConfigController {

private final static org.slf4j.Logger LOGGER = LoggerFactory.getLogger(PetController.class);

@GetMapping()
public List getAllLoggers() throws CoreException {
    
    LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
    
    List loggers = loggerContext.getLoggerList();
    
    List loggerDtos = new ArrayList<>();
    
    for (Logger logger : loggers) {
        
        if (Objects.isNull(logger.getLevel())) {
            continue;
        }
        
        LoggerDto dto = new LoggerDto(logger.getName(), logger.getLevel().levelStr);
        loggerDtos.add(dto);
    }
    
    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("All loggers retrieved. Total of {} loggers found", loggerDtos.size());
    }
    
    return loggerDtos;
}

@PutMapping
public boolean updateLoggerLevel(
        @RequestParam String name, 
        @RequestParam String level
)throws CoreException {
    
    LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
    
    Logger logger = loggerContext.getLogger(name);
    
    if (Objects.nonNull(logger) && StringUtils.isNotBlank(level)) {
        
        switch (level) {
            case "INFO":
                logger.setLevel(Level.INFO);
                LOGGER.info("Logger [{}] updated to [{}]", name, level);
                break;
                
            case "DEBUG":
                logger.setLevel(Level.DEBUG);
                LOGGER.info("Logger [{}] updated to [{}]", name, level);
                break;
                
            case "ALL":
                logger.setLevel(Level.ALL);
                LOGGER.info("Logger [{}] updated to [{}]", name, level);
                break;
                
            case "OFF":
            default: 
                logger.setLevel(Level.OFF);
                LOGGER.info("Logger [{}] updated to [{}]", name, level);
        }
    }
    
    return true;
}

}