java - Two independent classes that communicate using an Interface -

is possible have 2 independent class communicate implementing interface, , if so, how?

i think using interfaces little extreme here i'm assuming simplification of larger problem

public interface someinterface {      public void givestring(string string);      public string getstring();  } 

public class class1 implements someinterface{      string string;      public class1(string string) {         this.string = string;     }      //some code      @override     public void givestring(string string) {         //do whatever string         this.string=string;      }      @override     public string getstring() {         return string;     }    } 

public class class2 implements someinterface{      string string;      public class2(string string) {         this.string = string;     }      //some code      @override     public void givestring(string string) {         //do whatever string         this.string=string;      }      @override     public string getstring() {         return string;     }  } 

public class test{      public static void main(string args[]){         //all of code inside loop         class1 cl1=new class1("teststring1");         class2 cl2=new class2("teststring2");          //note can communicate now, no interface         cl1.givestring(cl2.string);           //but can communicate using interface         givestringviainterface(cl2,cl1);     }      //any class extended someinterface use method     public static void givestringviainterface(someinterface from, someinterface to){         to.givestring(from.getstring());     }    }