How to make an Object common to all classes

Question

I am building an application.
I need that one object (defined in the main class) be accesible to all other objects (classes). Also I need that any other object can change it.
How can I do that without passing the object's reference around? Actually I pass the reference through a SET method in each object. This is tedious!
Thanks a lot :)
iCamps

Answer 1

You could also create the Object using the singleton pattern. This way there is only one instance of the object, and every object that access it gets a reference to the same object.
public class SingletonObject {
    private SingletonObject instance;
    static {
        instance = new SingletonObject();
    public SingletonObject getInstance() {
        return instance;
    private SingletonObject() {
        // Constructor
    public synchronized method1() {}
    public synchronized method2() {}
}Then in your code access the SingletonObject like below. You can put a reference to the object in your constructor for each object that uses the SingletonObject, or jsut access it in the neccessary methods with SingletonObject.getInstance().
public class YourClass {
    public void someMethod() {
        SingletonObject so = SingletonObject.getInstance();
        so.method1();
        so.method2();
}