Question

What is the most efficient way to convert data from nested lists to an object array (which can be used i.e. as data for JTable)?

List<List> table = new ArrayList<List>();  for (DATAROW rowData : entries) {     List<String> row = new ArrayList<String>();      for (String col : rowData.getDataColumn())         row.add(col);      table.add(row); }  // I'm doing the conversion manually now, but // I hope that there are better ways to achieve the same Object[][] finalData = new String[table.size()][max]; for (int i = 0; i < table.size(); i++) {     List<String> row = table.get(i);      for (int j = 0; j < row.size(); j++)         finalData[i][j] = row.get(j); } 

Many thanks!

Answer 1

//defined somewhere List<List<String>> lists = ....  String[][] array = new String[lists.size()][]; String[] blankArray = new String[0]; for(int i=0; i < lists.size(); i++) {     array[i] = lists.get(i).toArray(blankArray); } 

I don’t know anything about JTable, but converting a list of lists to array can be done with a few lines.