Question

I have executed a query using JDBC and traversing the resultset I have stored all fields in List in java.

List<String> dataList=new ArrayList<String>();
        while(res.next())
        {
            dataList.add(res.getString(1));
            dataList.add(res.getString(2));
            dataList.add(res.getString(3));
            dataList.add(res.getString(4));
            dataList.add(res.getString(5));
            dataList.add(res.getString(6));
            dataList.add(res.getString(7));
        }
        Iterator<String> it= dataList.iterator();

As I have added directly into list so how can I get this 7 fields while traversing the iterator.
Means:

while(it.hasNext())
{
   String f1=it.next();

}

Like wise everytime I want 7 fields at a time
and next 7, next 7……. so on
Using this while loop how can I get those 7 fields (one row in table having 7 field) at a time.

I get little bit confuse here. Please help me.

Thanks

Answer 1

What you want to do is actually create another object that stores all seven of the values.

Then create a list of these entries so that you can access one row at a time, which is what I think you are asking.

First create a class for the row.

private static class Entry {
    String[] row;

    public Entry ( ResultSet r ) {
        row = new String [ 7 ];
        for (int i = 1; i <= 7; i++) {
            row[i] = r.getString(i);
        }
    }
}

Using that, you can then create a list of Entry objects.

List<Entry> entryList = new ArrayList <Entry> ();

while(res.next())
{
    entryList.add ( new Entry ( res ) );
}

Then, you can go ahead and loop through entryList and get any specific entry you would want.

Of course, if you have specific values, it might be wise to create instance variables of type String for Entry rather than an array of Strings.

By that I mean you could do this:

private static class Entry {
    String column1; // rather than name column1 use what the column semantically represents

    String column2;

    // ...

    public Entry ( ResultSet r ) {
        column1 = r.getString(1);
        // ...
    }

This way, you can also calls like r.getInt(i) for certain columns which have an different type other than String.

Good luck!