Problem in compiling java code

Question

Hi,
I have class (say A) which has an inner class (say B). There is a method(say m1) in A which has a return type as a Vector (say v1). The skeletal of the code is as :-
public class A {
public A (String mesg) {
System.out.println(mesg);
//inner class B starts
public class B {
public String name;
public int age;
public B (String name, int age) {
this.name = name;
this.age = age;
//inner class B ends
public final Vector m1 (String code) {
Vector v1 = new Vector();
B b;
if (code.equals("1111")) {
b = new B("Tutty",26);
v1.addElement(b);
return v1;
public final String m2 (B b1) {
return b1.name;
public final int m3 (B b1) {
return b1.age;
// end of class A
The above class is called in the following code :-
public class check{
public static void main(String args[]) {
A a1 = new A1("Hello");
Vector v = new Vector();
v = a1.m1("1111");
for (int i=0; i<=v.size(); i++) {
String name = a1.m2(v.elementAt(i));
//end of class check
When i compile the above class check.java , i get the following error:-
check.java:15: m2(A.B) in A cannot be applied to (java.lang.Object)
String name = a1.m2(v.elementAt(i));
^
1 error
Kindly help me in rectifying the error.
Thanks in advance.
regards,
Parag, Asmita.

Answer 1

Hi,
Thanks for the re-designed code.
But i think if i tell you what exactly we are aiming at, may be you can give us some better and a compact solution.
We are writing some classes which are based upon entities like student, department etc etc. The return type of the various methods in these classes was becoming a debatable issue, esp. when the output was in the form of an m by n matrix...basically of 'm' columns ('m' fields of the table which was queried) and 'n' rows(records). Out of the various options, we decided that we pass every single record (of the result set) as an object (which will be non-interpretable by the programmer using our class) in a single vector.
Speaking in an elaborate way, if the query fired was like "show departments with code and name", the output was :-
"select deptcode,deptname from dept order by deptcode";
deptcode deptname
01 Chemical Enginnering
02 Computer Engineering
(etc etc)
Now we decided to pass the above as :-
Vector v1 = new Vector();
and to ' v1' we didn't want to add the string as it is but the object of the record like
v1.addElement ( objectOf(01 and Chemical Engineering) );
v1.addElement ( objectOf(02 and Computer Engineering) );
Now this 'objectOf' was upto us to decide.
So we decided that it can be an object of some inner class (in our case B). But now we realised that we have to reveal the class B also to others (during the A.B casting). So is there a way we can keep this 'objectOf' just to ourselves and when the programmer asks for 'getDeptCode(objectOf(01 and Chemical Engineering))', we have our method to interpret the argument passed and then pass the department code.
I hope i have not bugged much and made myself clear. I am sure the doubt may be silly, but we have still not come down to any solution and hence we seek help/suggestions.
thanks,
Asmita.