public interface Logger {
void debug(String message);
void info(String message);
void warn(String message);
void error(String message);
}
public class LogManager implements Logger {
private static final Logger LOGGER = new LogManager();
private LogManager() {
}
public static Logger getLogger() {
return LOGGER;
}
@Override
public void debug(String message) {
}
@Override
public void info(String message) {
}
@Override
public void warn(String message) {
}
@Override
public void error(String message) {
}
}
public class MyApp {
private static final Logger LOGGER = LogManager.getLogger();
public void doSomething() {
LOGGER.debug("This is a debug message.");
LOGGER.info("This is an info message.");
LOGGER.warn("This is a warn message.");
LOGGER.error("This is an error message.");
}
}
