ArrayList overwriting error

[Captain Carrot]

Hello,
I work with JSF and I in one of my Java beans this code:

Public class MasterBean {
 
	private List <ItemBean> coll, rwlst;

	Public MasterBean() throws SQLException {
        
	    ResultSet rslt =null;
	    try{
	    
	    String u ="jdbc: oracle: thin: @ 192.168.100.35:1521: ORCL";
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
Connection conn = DriverManager.getConnection(u,"user","not");


Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
rslt = stmt.executeQuery("SELECT FROM sym PVMCA WHERE id_cc = 11042920002");
	    
	    }
	    catch (...)}     
	    
	    rwlst = new ArrayList <ItemBean>();
	    while (rslt.next())
	    {
	      coll = new ArrayList <ItemBean>();
String tmpSym = rslt.getString("sym");

coll.add(new ItemBean(tmpSym));
	    }
	}
	
	Public List getList <ItemBean>() {
		return coll;
	}
 
	Public void setlist(List <ItemBean> coll) {
		this.coll = coll;
	}
	
}

When I compile the code I get an error, I think that this is a Arraylist overwriting problem. Please check my code and if I am wrong somewhere then please guide me with the correct.

[SoftWore]

Hello,
Yes you will get the following error because in your while loop each time you created a new ArrayList

while (rs.next())
	    {
	      coll = new ArrayList <ItemBean>();
String tmp = rs.getString("sym");

coll.add(new ItemBean(tmp));
	    }

Please correct your mistake then check if your code compiles successfully.

[Linux-Us]

Hello,
Yes, I agree with the above post and you can modify your code something like this
Here is the modified code

 coll = new ArrayList <ItemBean>();
while (rs.next())
	    {
	     
	      String tmp = rs.getString("sym");

coll.add(new ItemBean(tmp));
	    }

Another thing, your bean that accesses your Database is concerning me, I guess you have designed the beans correctly.

[InterNetWorKed]

Hello,
I think it's normal. You create the "coll" it ever turn of your loop. We must remove this line in the while loop.
Here is the part of code for it

Coll = new ArrayList <ItemBean>();

This will give you a more effective result. If you need any more help regarding this topic then you can post here and we will try to solve your queries.

[Captain Carrot]

Hello,
Thank you for your answers, but I have one more question for your guys, why access to the database is not good? I have not put the good version of the database, is this causing me a problem? I use a stored procedure to access my database, but the connection terminates, prepare it there another way? Any help regarding this will be appreciated. Thanks in advance.

[cyber-noob]

Hello,
The access to your database given is correct but the level of conceptual separate, differentiates the layers, that is view, trends and data. This is not the case if you have your bean that accesses to the database. I think you should do some study on the design patterns, since you're working on the JSF MVC 2. I recommend you to read some articles or tutorials on the design pattern that will help you.
Check out if the Introspection in Java Beans help you
Why we use Introspection in Java Beans?