Slf4JLoggerFactory Class — netty Architecture

Source Code

common/src/main/java/io/netty/util/internal/logging/Slf4JLoggerFactory.java lines 28–65

public class Slf4JLoggerFactory extends InternalLoggerFactory {

    @SuppressWarnings("deprecation")
    public static final InternalLoggerFactory INSTANCE = new Slf4JLoggerFactory();

    /**
     * @deprecated Use {@link #INSTANCE} instead.
     */
    @Deprecated
    public Slf4JLoggerFactory() {
    }

    Slf4JLoggerFactory(boolean failIfNOP) {
        assert failIfNOP; // Should be always called with true.
        if (LoggerFactory.getILoggerFactory() instanceof NOPLoggerFactory) {
            throw new NoClassDefFoundError("NOPLoggerFactory not supported");
        }
    }

    @Override
    public InternalLogger newInstance(String name) {
        return wrapLogger(LoggerFactory.getLogger(name));
    }

    // package-private for testing.
    static InternalLogger wrapLogger(Logger logger) {
        return logger instanceof LocationAwareLogger ?
                new LocationAwareSlf4JLogger((LocationAwareLogger) logger) : new Slf4JLogger(logger);
    }

    static InternalLoggerFactory getInstanceWithNopCheck() {
        return NopInstanceHolder.INSTANCE_WITH_NOP_CHECK;
    }

    private static final class NopInstanceHolder {
        private static final InternalLoggerFactory INSTANCE_WITH_NOP_CHECK = new Slf4JLoggerFactory(true);
    }
}