I am new to Java 5 Programming and I am facing an issue with Generics
as below
In my java application , My main class is as below (I have replicated
the original scenario in the test program here )
import java.util.ArrayList;
public class TestGeneric {
public static void main(String args[]) {
ArrayList al = new ArrayList ();
TestClass tc = new TestClass();
al = tc.getList();
System.out.println(al);
}
}
And the TestClass is as below
import java.util.ArrayList;
public class TestClass {
public ArrayList getList() {
ArrayList list1 = new ArrayList();
list1.add("Hello1");
list1.add("Hellow1");
ArrayList list2 = new ArrayList ();
list2.add("Hello2");
list2.add("Hellow2");
ArrayList list3 = new ArrayList ();
list3.add(list1);
list3.add(list2);
return list3;
}
}
The method getList in TestClass returns as ArrayList of ArrayLists .
If I need to implement the above two class using Generics , how Can I
go about it .
Will it be ArrayList <ArrayList > al = new ArrayList <ArrayList>
(); in the main program ? or
ArrayList <Object > al = new ArrayList <Object> ();
Please help
Thanks
Sam