Create vector for DefaultTableModel

Question

public static DefaultTableModel localQuery(String searchTerm){

    List<String[]> result = new ArrayList<String[]>();
    String[] rowResult = new String[7];
    Vector<String[]> rows = new Vector<String[]>();
    Vector<String> columnNames = new Vector<String>();
    Statement stmt = null;      
    try {
      stmt = conn.createStatement();
      ResultSet rs = stmt.executeQuery(searchTerm);
      while(rs.next()){
          rowResult = new String[13];

          String currentId= rs.getString("CurrentId");
          String manufacturer = rs.getString("Constructor");
          String type = rs.getString("ACType");
          String series = rs.getString("Series");
          String index = rs.getString("KeyNo");
          String operator = rs.getString("Operator");
          String baseCountry = rs.getString("Home_Country");
          String baseAirport = rs.getString("Home_Airfield");
          String cn = rs.getString("Con");
          String lineNo = rs.getString("LineNum");
          String hex = rs.getString("Hexcode");
          String selcal=rs.getString("Selcal");
          String acName = rs.getString("ACName");

          rowResult[0] = (currentId);
          rowResult[1] = (manufacturer);
          rowResult[2] = (type);
          rowResult[3] = (series);
          rowResult[4] = (operator);
          rowResult[5] = (baseCountry);
          rowResult[6] = (baseAirport);
          rowResult[7] = (cn);
          rowResult[8] = (lineNo);
          rowResult[9] = (hex);
          rowResult[10] = (selcal);
          rowResult[11] = (acName);
          rowResult[12]= (index);
          result.add(rowResult);

      }

    columnNames.add("Reg.");
    columnNames.add("Manufacturer");
    columnNames.add("Type");
    columnNames.add("Series");
    columnNames.add("Operator");
    columnNames.add("Home Country");
    columnNames.add("Home Airfield");
    columnNames.add("C/N");
    columnNames.add("Line #");
    columnNames.add("Hex");
    columnNames.add("Selcal");
    columnNames.add("Aircraft Name");
    columnNames.add("");





      rs.close();
      stmt.close();


    //Convert from List<String[]> to a suitable vector for  resultTable... Help!!!


  DefaultTableModel resultTable = new DefaultTableModel(rows, columnNames);
  return resultTable;

    }

Hi! I'm trying this method to return a DefaultTableModel to use on a JTable. I'm struggling to format the data pulled from the database into a model friendly format. Take it easy on me, this is my third ever day of programming of any sort!

Thanks in advance :)

Answer 1

1. You can get the column header dynamically using ResultSetMetaData ← API link

   ResultSetMetaData rsMeta = resultSet.getMetaData();
   int numberOfCols = rsMeta.getColumnCount();
   Vector<String> columnNames = new Vector<>();   // your columns names
   for (int i = 1; i <= numberOfCols; i++ ){
       columnsNames.add(rsMeta.getColumnName(i));
   }
   

2. You don't need the extra Vector or the List for the data. Just first declare your DefaultTableModel with the constructor arguments ( Vector/Object[] colNames, int rows). Then just use the method addRow from the DefaultTableModel

   DefaultTableModel model = new DefaultTableModel(columnNames, 0);
   
   while (resultSet.next()) {
       String data1 = resultSet.getString(1);
       String data2 = resultSet.getString(2);
       ...
       Object[] rowData = new Object[] { data1, data2, ... };
       model.addRow(rowData);
   }
   
   return model;
   

3. Or, instead of 2., to make sure you're getting the correct number of columns, you could use the Vector inside the while loop and loop through the column data.

   DefaultTableModel model = new DefaultTableModel(columnNames, 0);
   
   while (resultSet.next()) {
       Vector<String> row = new Vector<>();
       for (int i = 1; i <= numberOfCols; i++) {
           row.add(resultSet.getString(i));
       }
       model.addRow(row);
   }
   
   return model;
   

See more methods and constructors see DefaultTableModel API