在while（rset.next）内调用方法时用尽的结果集

Question

I'm getting an Exhausted resultset form the following code.

I've tried a few different things now and can't find a solution,
if I don't call the songs method it works, but the songs method works when it's called, can't get my head around it, hoping I'm missing something simple.

public void refreshList() {

    rset = po.getProduct();

    if (plist.size() > 0) {
        for (int i = plist.size() - 1; i >= 0; i--) {
            plist.remove(i);
        }
    }
    try {
        while (rset.next()) {

            songs(rset.getString(1));
            CD c = new CD(alist);

            Product p = new Product(rset.getString(1), 
                    rset.getString(2),
                    rset.getString(3), 
                    rset.getDouble(4), 
                    rset.getDouble(5), 
                    rset.getInt(6),
                    rset.getString(7),
                    rset.getString(8),
                    rset.getString(9), 
                    rset.getDouble(10), c);
            plist.add(p);

        }
    } catch (Exception ex) {
        System.out.println(ex);
    }
}


  public void songs(String ID)
{
    rset = po.getSongs();
    alist = new ArrayList<Song>();
    try {
        while (rset.next()){
            Song s = new Song(rset.getString(1),
                    rset.getString(2), 
                    rset.getString(3));
            slist.add(s);
        }   
    } 
    catch (Exception ea) {
        System.out.println(ea);
    }

    for(int i = 0; i < slist.size(); i++)
    {
        if(slist.get(i).getSong_id().equals(ID))
        {
            alist.add(slist.get(i));
        }
    }
}

Answer 1

Inside refreshList you have while (rset.next()) loop, on each iteration of it you have songs(rset.getString(1)); , which itself has while(rset.next() . This leads to result set exhaustion, because when you return from songs() you try to take some more data from the current position of result set, while in songs() you got out of while (rset.next()) loop, ie retrieved all its rows. Consider refactoring your code to avoid nested loops based on result set.