Can I use array of Beans?

[chaitanya karthikk]

Hi everybody, I am Chaitanya, I have a link which when clicked requests list of users present. There is a model which selects the list of users with their names.

If it is one single user all his information is retrieved and dumped in to the Bean. Now I am retrieving list of users with their names only. Not the entire details.

I have setter and getter methods in Bean. So if I retrieve 10 user names, then I should have a array of 10 Beans. Can I do like this?

And this Bean consists of 25 setter and getter methods. Here I am using only set user name property. The rest of the setter and getter methods are useless.

Can I go with Beans or simply create an array? If I should go with Beans, then, can I use the previous Bean which consists of 25 setter and getter properties. Or shall I create another Bean which exactly consists the name property?

Thank you all in advance. Have a good day.

[Bear Bibeault]

Of course -- why not? Are you running into any specific difficulty?

[chaitanya karthikk]

Bear Bibeault wrote:Of course -- why not? Are you running into any specific difficulty?

No Mr. Bear, I don't have any specific difficulty. I just don't know that should I create array of Beans or go for an array. Thats it. Thank you sir.

[chaitanya karthikk]

Hi Mr. Bear, Array of beans is not working, it is reporting a null pointer exception.

package web.it.models;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import web.it.beans.AllFacultyBean;

public class DeptStaffModel
{
	public AllFacultyBean[] getAllFac(Connection con,int dept_id)
	{
		AllFacultyBean afb[]=null;
		try
		{
			int i=0;
			Statement stmt=con.createStatement();
			ResultSet res=stmt.executeQuery("select count(*) from dept_it_db.faculty where dept_id="+dept_id+"");
			if(res.next())
				afb=new AllFacultyBean[res.getInt(1)];
			res=stmt.executeQuery("select f.name,d.des_name from dept_it_db.faculty f,dept_it_db.designations d where f.dept_id="+dept_id+" and f.des_id=d.des_id");
			while(res.next())
			{
				afb[i].setName(res.getString(1));
				afb[i].setDes(res.getString(2));
				i++;
			}
		}catch(Exception e){e.printStackTrace();}
		return afb;
	}
}

Can you please tell me where is the mistake? Thank you in advance.

[Bear Bibeault]

You need to check your basic Java logic.

[chaitanya karthikk]

Bear Bibeault wrote:You need to check your basic Java logic.

Everything is fine, it is working with String Array, not with Bean Array. I just replaced the Bean class with String. It worked fine. Coming to Beans it is not working.

[Hebert Coelho]

Hello.

What's the error message?

[chaitanya karthikk]

It is giving a null pointer exception Mr. Herbert.

[Hebert Coelho]

Wich line?

[chaitanya karthikk]

Hebert Coelho wrote:Wich line?

The error lies in the while loop. I also checked whether there are any records in the faculty table. There are 3 records. So the Bean is initialized to array of size 3.

[Hebert Coelho]

I know this is not the answer you want to hear but, trust me, is the best answer for you...

Bear Bibeault wrote:You need to check your basic Java logic.

When you find it, you won't never fell for it again. [=

[chaitanya karthikk]

I did not understand what you said

[Nilesh Miskin]

@Chaitanya
The way you are creating an array of beans is wrong. Please see this example for a hint.

[Christophe Verré]

Also, the Arrays tutorial.