working with multiple records using sql

[CorumMc]

Hello all,
I have created my first value objects; passed a search variable to my data access class, ran the query, populated the value object and returned it. Pretty straightforward.

Now I need to learn how to do the same with multiple records. I thought to populate an arraylist with a value object for each record. But when I try to retrieve one of the elements:
"ValueObject = ArrayList.get(i)"
I get an error saying it can't convert an Object to my ValuObject
Is there another method I need to use to retrieve the object I save to an arraylist so that I can then access that object's methods?

In the test method below I am trying to populate the arraylist and then return 1 of the valueobject elements.


private RequestVO selQry(String query,RequestVO cust)
{//populates the Value Object with the Query string
ArrayList ranklist = new ArrayList();
try
{
java.sql.Statement stmt = Con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);

ResultSet rsName = stmt.executeQuery(query);
while(rsName.next())
{
cust.setReqID(rsName.getInt("RequestID"));
cust.setReqTitle(rsName.getString("RequestTitle"));
ranklist.add(i, cust);
i++;
}
}
catch(Exception e)
{ System.out.println(e.getMessage());
}
cust = ranklist.get(2);
return cust;
}

[sjalle]

You must typecast the Object pointer returned from the ArrayList in order to make the java compiler understand what you are doing.

in the line:

cust = ranklist.get(2);

you use the typechast syntax to do this:

cust = (RequestVO) ranklist.get(2);

[CorumMc]

Originally posted by sjalle
You must typecast the Object pointer returned from the ArrayList in order to make the java compiler understand what you are doing.

in the line:

cust = ranklist.get(2);

you use the typechast syntax to do this:

cust = (RequestVO) ranklist.get(2);

Thanks very much!
I'm entering it wrong somehow though, because I keep displaying only the last record added. (which admittedly is an improvement over what I'd had before )

I've tried a couple of different things with no change. Here's what I've entered:

cust = (RequestVO) ranklist.get(2);
System.out.println(cust.getReqID());

RequestVO cust2 = new RequestVO();
cust2 = (RequestVO) ranklist.get(1);
System.out.println("cust2 = "+cust2.getReqID());

RequestVO cust3 = (RequestVO)ranklist.get(2);
System.out.println("cust3 = "+cust3.getReqTitle());
return cust;

[sjalle]

To make a long story short, I've coded these two snippets:

First, I've altered your request method to what I think you want it to do....

private ArrayList selQry(String query) {
    //populates the Value Objects with the Query string
    ArrayList ranklist = new ArrayList();
    try {
      java.sql.Statement stmt = con.createStatement(ResultSet.
          TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
      ResultSet rsName = stmt.executeQuery(query);
      while (rsName.next()) {
        // ** You must instantiate a new object for each record:
        RequestVO cust=new RequestVO();
        cust.setReqID(rsName.getInt("RequestID"));
        cust.setReqTitle(rsName.getString("RequestTitle"));
        ranklist.add(cust);
      }
    }
    catch (Exception e) {
      System.out.println(e.getMessage());
    }
    return ranklist; //** return the whole lot
  }

And this is how I think you want to use it:

  ArrayList aList=selQry("select * from atable where RequestID > 10");
  for (int i=0;i<aList.size();i++) {
      RequestVO rvo=(RequestVO)aList.get(i);
      System.out.println("reqTitle: "+rvo.getReqTitle());
      System.out.println("regID: "+rvo.getReqID());
  }

[CorumMc]

You Rock.

Thanks very much,
Chris