Java CustomTableModel无法正确排序

Question

I add items to a model that is linked to a table. When I select an item in this table, things happen depending on what item it is. For now I just have a System.out telling me the items name.

If I have two items called 'A' and 'B', when I select either their respective name is written to the console as expected, however, if I sort them by name, so that 'B' is placed in the row over 'A', the sorting never happened internally but only visually. So if I now select 'A', the console prints out 'B', and vice versa.

The sorter is declared in the mainclass, itemList is a JTable itemList.setAutoCreateRowSorter(true);

Apparently I must have failed to include some default method that's needed for this sorterfunctionality. "default methods" is declared towards the end in the code-snippet, from and after the method 'getColumnName'.

class ItemModel extends AbstractTableModel
{
    ArrayList<MCItem> items = new ArrayList<MCItem>();
    private int currentMaxRows = 0;
    private String[] columnNames = {"Item", "Total Units", "In Sorter"};
    private Class[] types = {String.class, Integer.class, Integer.class};
    private Object[][] data = new Object[currentMaxRows][getColumnCount()];

    public ArrayList<MCItem> getItems()
    {
        return items;
    }
    public void readdItems(Main m, ArrayList<MCItem> tempItems)
    {
        for(MCItem mci : tempItems)
        {
            mci.setMain(m);
            addRow(mci);
        }
    }
    public void emptyMe()
    {
        currentMaxRows = 0;
        items.clear();
        data = new Object[currentMaxRows][getColumnCount()];
        fireTableDataChanged();
    }
    public boolean isDuplicate(String s)
    {
        for(MCItem ci : items)
            if(ci.getName().equalsIgnoreCase(s))
                return true;
        return false;
    }
    public void updateItem(String id)
    {
        try
        {
            int foundRow = -1;
            for(int i = 0;i < currentMaxRows;i++)
                if(getValueAt(i, 0).toString().equalsIgnoreCase(id))
                {
                    foundRow = i;
                    break;
                }
            for(MCItem ii : items)
                if(ii.getName().equalsIgnoreCase(id))
                {
                    setItem(foundRow, ii);
                    fireTableDataChanged();
                    return;
                }
        }
        catch(NullPointerException e){}
    }
    public void addRow(MCItem item)
    {
        //check if we need to expand the dataArray
        if(currentMaxRows == items.size())
        {
            if(currentMaxRows == 0)
                data = new Object[++currentMaxRows][getColumnCount()];
            else
            {
                Object[][] tempArr = data;
                data = new Object[++currentMaxRows][getColumnCount()];

                for(int x = 0; x < tempArr.length; x++)
                    for(int y = 0; y < getColumnCount(); y++)
                        data[x][y] = tempArr[x][y];
            }
        }
        setItem(items.size(), item);
        items.add(item);
        fireTableDataChanged();
    }
    public void changeItem(int row, String name)
    {
        String originalName = (String) data[row][0];
        data[row][0] = name;
        for(MCItem ii : items)
            if(ii.getName().toString().equalsIgnoreCase(originalName))
            {
                ii.setName(name);
                return;
            }
        fireTableDataChanged();
    }
    public void removeItem(String id)
    {
        for(MCItem ii : items)
            if(ii.getName().toString().equalsIgnoreCase(id))
            {
                items.remove(ii);
                redoList();
                return;
            }
        fireTableDataChanged();
    }
    private void redoList()
    {
        ArrayList<MCItem> tempArr = (ArrayList<MCItem>) items.clone();
        emptyMe();
        for(MCItem ii : tempArr)
            addRow(ii);
    }
    private void setItem(int row, MCItem item)
    {
        int counter = 0;
        data[row][counter++] = item.getName();
        data[row][counter++] = item.getCount();
        data[row][counter++] = item.getSorterCount();
        fireTableDataChanged();
    }
    MCItem getMCItem(String name)
    {
        for(MCItem i : items)
            if(i.getName().equals(name))
                return i;
        return null;
    }
    public String getColumnName(int col)
    {
        return columnNames[col].toString();
    }
    public int getRowCount() 
    {
        return data.length;
    }
    public int getColumnCount() 
    {
        return columnNames.length;
    }
    public Object getValueAt(int row, int col) 
    {
        return data[row][col];
    }
    public Class getColumnClass(int columnIndex) 
    {
        return this.types[columnIndex];
    }
    public boolean isCellEditable(int row, int col)
    {
        return false;
    }
    public void setValueAt(Object value, int row, int col)
    {
        data[row][col] = value;
        fireTableCellUpdated(row, col);
    }
}

* Answer * The issue was never the tablemodel, but the JTable itself. When I want to present information based on the item selected, I called

currentMCItem = model.getMCItem(model.getValueAt(itemList.getSelectedRow(), 0).toString()); which returned the index in the JTable correctly, however when sorting all the indexes gets messed up and it's only the view that changes, so I had to redo that line to

currentMCItem = model.getMCItem(model.getValueAt(itemList.convertRowIndexToModel(itemList.getSelectedRow()), 0).toString());

So, the key is to call JTable.convertRowIndexToModel(SELECTED INDEX IN TABLE) in order to get the correct index, and use that as if it was the selectedRow.

Answer 1

You have a set of convert methods in JTable that you need to use. For example, convertColumnIndexToModel takes a view index and gives you back a corresponding column index in the model. Convert them and then get the values.