Global variables in Java

To define Global Variable you can make use of static Keyword

public class Example {
    public static int a;
    public static int b;
}

now you can access a and b from anywhere by calling

Example.a;

Example.b;

You don't. That's by design. You shouldn't do it even if you could.

That being said you could create a set of public static members in a class named Globals.

public class Globals {
   public static int globalInt = 0;
   ///
}

but you really shouldn't :). Seriously .. don't do it.

Another way is to create an interface like this:

public interface GlobalConstants
{
  String name = "Chilly Billy";
  String address = "10 Chicken head Lane";
}

Any class that needs to use them only has to implement the interface:

public class GlobalImpl implements GlobalConstants
{
  public GlobalImpl()
  {
     System.out.println(name);
  }
}

You are better off using dependency injection:

public class Globals {
    public int a;
    public int b;
}

public class UsesGlobals {
    private final Globals globals;
    public UsesGlobals(Globals globals) {
        this.globals = globals;
    }
}