L3-Budapest - Java - 5

README.md

Instructions

Today we start with a singleton exercise

Let's create a java program that has two classes Cat and Dog

They should have some fields it is up to you

And then create a Logger class which takes log messages and prints them to the screen.

• The Logger should be a singleton, create it like that.
• The logger should have logging levels defined in an enum these levels are error, info, debug.
• The logging level can be set at any time and then the Log messages should only appear if the match the level

Traditional log level use:

• When set to error only error messages are printed
• When set to info info and error messages are printed
• When set to debug debug, info and error messages are printed

Cat.java

public class Cat {
	private String name;
	private int age;
	private String color;

	public Cat(String name, int age, String color) {
		this.name = name;
		this.age = age;
		this.color = color;
	}

	public void meow() {
		System.out.println("Meow!");
	}

	public void sleep() {
		System.out.println("Zzzz...");
	}

	public void eat(String food) {
		System.out.println("Eating " + food);
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getColor() {
		return color;
	}

	public void setColor(String color) {
		this.color = color;
	}
}

Dog.java

public class Dog {
	private String name;
	private int age;
	private String breed;

	public Dog(String name, int age, String breed) {
		this.name = name;
		this.age = age;
		this.breed = breed;
	}

	public void bark() {
		System.out.println("Woof woof!");
	}

	public void eat(String food) {
		System.out.println(name + " is eating " + food);
	}

	public void sleep() {
		System.out.println(name + " is sleeping Zzz...");
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getBreed() {
		return breed;
	}

	public void setBreed(String breed) {
		this.breed = breed;
	}
}

Logger.java

public class Logger {
	private static Logger instance;
	private LogLevel logLevel;

	private Logger() {
		// Initialize log level to default, e.g., LogLevel.INFO
		this.logLevel = LogLevel.INFO;
	}

	public static synchronized Logger getInstance() {
		if (instance == null) {
			instance = new Logger();
		}
		return instance;
	}

	public void setLogLevel(LogLevel logLevel) {
		this.logLevel = logLevel;
	}

	public void log(LogLevel messageLevel, String message) {
		if (messageLevel.ordinal() <= logLevel.ordinal()) {
			System.out.println("[" + messageLevel + "] " + message);
		}
	}
}

LogLevel.java

public enum LogLevel {
	ERROR,
	INFO,
	DEBUG,
}