Implements a custom CellEditor for a JTable with 2 columns (String, Integer) and n Rows

Question

I have a JTable with N rows and 2 columns I need to implement a custom CellEditor class to access the data input of each cell with

table.getCellEditor(int row, int column).getCellEditorValue()

I have used this CellEditor class

class MyEditor extends DefaultCellEditor {
        /**
         * 
         */
        private static final long serialVersionUID = 1L;
        private JTextField textField;
        private boolean valueSet;
          public MyEditor() {
            super(new JTextField());
          }

          @Override
            public boolean isCellEditable(EventObject eo) {
                System.err.println("isCellEditable");
                if (eo instanceof KeyEvent) {
                    KeyEvent ke = (KeyEvent) eo;
                    System.err.println("key event: " + ke.getKeyChar());
                    textField.setText(String.valueOf(ke.getKeyChar()));
                    valueSet = true;
                } else {
                    valueSet = false;
                }
                return true;
            }
    }

but is not enough to access the data in the right cell position... (and seems that all the table is seen as a whole cell)

all the example that I have found are relative to using cell editor to block the editing cell if the input is not correct but anything clear enough to help me to solve the problem.

PS If you want try to see in detail how the whole interface (not)works the whole code is this:

public class CompileDataJob extends JFrame {
      private boolean DEBUG = false;
    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    CompileDataJob frame = new CompileDataJob();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public CompileDataJob() {
        setTitle("Inserisci i parametri dei lavori");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 551, 293);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);

        JPanel panel_1 = new JPanel();
        final JTable table = new JTable(new MyTableModel());

        JButton btnNewButton = new JButton("    OK   ");
        btnNewButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                try{
                    DataJobManager.azzeraListaLavori();
                    int numJob=DataJobManager.loadNumeroLavori();
                    LinkedList<Job> listaLavori=new LinkedList<Job>();
                    String id;
                    int time;
                    for (int rowIndex=0; rowIndex<numJob; rowIndex++){
                            id=(String)(table.getCellEditor(rowIndex,0).getCellEditorValue());
                            time=Integer.parseInt(((String)((table.getCellEditor(rowIndex, 1)).getCellEditorValue())));
                            Job l=new Job(id,time);
                            listaLavori.add(l);
                    }
                        DataJobManager.saveListaLavori(listaLavori);
                        CompileDataJob.this.dispose();
                        JOptionPane.showMessageDialog(CompileDataJob.this,"Data Saved");
                }catch(Exception ecc){
                    JOptionPane.showMessageDialog(CompileDataJob.this,"Error during the saving.");
                }
            }
        });
        panel_1.add(btnNewButton);

        JButton btnNewButton_1 = new JButton("Cancel");
        btnNewButton_1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                CompileDataJob.this.dispose();
            }
        });

        JPanel panel = new JPanel();



        table.setDefaultEditor(Object.class,new MyEditor());

        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);
        table.getSelectionModel().addListSelectionListener(
                new ListSelectionListener() {
                    public void valueChanged(ListSelectionEvent event) {
                        int viewRow = table.getSelectedRow();
                        JLabel statusText=new JLabel();
                        if (viewRow < 0) {
                            //Selection got filtered away.
                            statusText.setText("");
                        } else {
                            int modelRow = 
                                table.convertRowIndexToModel(viewRow);
                            statusText.setText(
                                String.format("Selected Row in view: %d. " +
                                    "Selected Row in model: %d.", 
                                    viewRow, modelRow));
                        }
                    }
                }
        );


                //Create the scroll pane and add the table to it.
                JScrollPane scrollPane = new JScrollPane(table);

                        //Set up column sizes.
                        initColumnSizes(table);

        panel_1.add(btnNewButton_1);
        GroupLayout gl_contentPane = new GroupLayout(contentPane);
        gl_contentPane.setHorizontalGroup(
            gl_contentPane.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_contentPane.createSequentialGroup()
                    .addGroup(gl_contentPane.createParallelGroup(Alignment.TRAILING, false)
                        .addComponent(panel_1, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addComponent(panel, GroupLayout.DEFAULT_SIZE, 525, Short.MAX_VALUE))
                    .addContainerGap())
        );
        gl_contentPane.setVerticalGroup(
            gl_contentPane.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_contentPane.createSequentialGroup()
                    .addComponent(panel, GroupLayout.PREFERRED_SIZE, 213, GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(ComponentPlacement.RELATED, 61, Short.MAX_VALUE)
                    .addComponent(panel_1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
        );
        GroupLayout gl_panel = new GroupLayout(panel);
        gl_panel.setHorizontalGroup(
            gl_panel.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_panel.createSequentialGroup()
                    .addGap(11)
                    .addComponent(scrollPane, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(12, Short.MAX_VALUE))
        );
        gl_panel.setVerticalGroup(
            gl_panel.createParallelGroup(Alignment.LEADING)
                .addGroup(gl_panel.createSequentialGroup()
                    .addGap(5)
                    .addComponent(scrollPane, GroupLayout.DEFAULT_SIZE, 197, Short.MAX_VALUE)
                    .addContainerGap())
        );
        panel.setLayout(gl_panel);
        contentPane.setLayout(gl_contentPane);



    }

    private void initColumnSizes(JTable table) {
        MyTableModel model = (MyTableModel)table.getModel();
        TableColumn column = null;
        Component comp = null;
        int headerWidth = 0;
        int cellWidth = 0;
        Object[] longValues = model.longValues;
        TableCellRenderer headerRenderer =
            table.getTableHeader().getDefaultRenderer();

        for (int i = 0; i < 2; i++) {
            column = table.getColumnModel().getColumn(i);

            comp = headerRenderer.getTableCellRendererComponent(
                                 null, column.getHeaderValue(),
                                 false, false, 0, 0);
            headerWidth = comp.getPreferredSize().width;

            comp = table.getDefaultRenderer(model.getColumnClass(i)).
                             getTableCellRendererComponent(
                                 table, longValues[i],
                                 false, false, 0, i);
            cellWidth = comp.getPreferredSize().width;

            if (DEBUG) {
                System.out.println("Initializing width of column "
                                   + i + ". "
                                   + "headerWidth = " + headerWidth
                                   + "; cellWidth = " + cellWidth);
            }

            column.setPreferredWidth(Math.max(headerWidth, cellWidth));
        }
    }

    class MyEditor extends DefaultCellEditor {
        /**
         * 
         */
        private static final long serialVersionUID = 1L;
        private JTextField textField;
        private boolean valueSet;
          public MyEditor() {
            super(new JTextField());
          }

          @Override
            public boolean isCellEditable(EventObject eo) {
                System.err.println("isCellEditable");
                if (eo instanceof KeyEvent) {
                    KeyEvent ke = (KeyEvent) eo;
                    System.err.println("key event: " + ke.getKeyChar());
                    textField.setText(String.valueOf(ke.getKeyChar()));
                    //textField.select(1,1);
                    //textField.setCaretPosition(1);
                    //textField.moveCaretPosition(1);
                    valueSet = true;
                } else {
                    valueSet = false;
                }
                return true;
            }
    }





    class MyTableModel extends AbstractTableModel {
        /**
         * 
         */
        private static final long serialVersionUID = 1L;
        private String[] columnNames = {"Nome Job", "Durata"};
        int numJob=DataJobManager.loadNumeroLavori();
        private Object[][] data = getDatiDefaultTabella();

        public class Job {
            public int time; // Should n't this be a long?
            public String jobName;
        }

        public Object[][] getDatiDefaultTabella(){
            Object[][] tabella=new Object[numJob][2];
            for(int i=0; i<numJob; i++){
                for(int j=0; j<2; j++){
                    tabella[i][j]="inserisci dati";
                }
            }

            return tabella;
        }

        public Object[][] getTabella(){
            return data;
        }


        public int getColumnCount() {
            return columnNames.length;
        }

        public int getRowCount() {
            return numJob;
        }

        public String getColumnName(int col) {
            return columnNames[col];
        }

        public Object getValueAt(int row, int col) {
            return data[row][col];
        }

        /*
         * JTable uses this method to determine the default renderer/
         * editor for each cell.  If we didn't implement this method,
         * then the last column would contain text ("true"/"false"),
         * rather than a check box.
         */
        public Class getRowClass(int r) {
            return getValueAt(r, 0).getClass();
        }

        public Class getColumnClass(int c) {
            return getValueAt(0, c).getClass();
        }


        /*
         * Don't need to implement this method unless your table's
         * editable.
         */
        public boolean isCellEditable(int row, int col) {
            //Note that the data/cell address is constant,
            //no matter where the cell appears onscreen.
            return true;
        }



        /*
         * Don't need to implement this method unless your table's
         * data can change.
         */
        public void setValueAt(Object value, int row, int col) {
            if (DEBUG) {
                System.out.println("Setting value at " + row + "," + col
                                   + " to " + value
                                   + " (an instance of "
                                   + value.getClass() + ")");
            }

            data[row][col] = value;
            fireTableCellUpdated(row, col);

            if (DEBUG) {
                System.out.println("New value of data:");
                printDebugData();
            }
        }

        private void printDebugData() {
            int numRows = getRowCount();
            int numCols = getColumnCount();

            for (int i=0; i < numRows; i++) {
                System.out.print("    row " + i + ":");
                for (int j=0; j < numCols; j++) {
                    System.out.print("  "  + data[i][j]);
                }
                System.out.println();
            }
            System.out.println("--------------------------");
        }
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */

        public void run() {
            try {
                CompileDataJob frame = new CompileDataJob();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
}

Answer 1

Ok, I guess I got it. I optimized your code a little and deleted stuff I didn't need. You may add it again.

Here is CompileDataJob

public class CompileDataJob extends JFrame {
    final boolean DEBUG = false;
  private final JPanel contentPane;

  /**
   * Launch the application.
   */
  public static void main(String[] args) {
      EventQueue.invokeLater(new Runnable() {
          public void run() {
              try {
                  CompileDataJob frame = new CompileDataJob();
                  frame.setVisible(true);
              } catch (Exception e) {
                  e.printStackTrace();
              }
          }
      });
  }

  /**
   * Create the frame.
   */
  public CompileDataJob() {
      setTitle("Inserisci i parametri dei lavori");
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setBounds(100, 100, 551, 293);
      contentPane = new JPanel();
      contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
      setContentPane(contentPane);

      JPanel panel_1 = new JPanel();
      final JTable table = new JTable(new MyTableModel());

      JButton add = new JButton(" ADD ");
      add.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e) {
            ((MyTableModel)table.getModel()).addRow(new Job(0, ""));
        }
      });

      JButton btnNewButton = new JButton("    OK   ");
      btnNewButton.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent e) {
              try{
                      DataJobManager.saveListaLavori(((MyTableModel)table.getModel()).getJobs());
                      CompileDataJob.this.dispose();
                      JOptionPane.showMessageDialog(CompileDataJob.this,"Data Saved");
              }catch(Exception ecc){
                  JOptionPane.showMessageDialog(CompileDataJob.this,"Error during the saving.");
              }
          }
      });
      panel_1.add(btnNewButton);
      panel_1.add(add);
      JButton btnNewButton_1 = new JButton("Cancel");
      btnNewButton_1.addActionListener(new ActionListener() {
          public void actionPerformed(ActionEvent arg0) {
              CompileDataJob.this.dispose();
          }
      });

      JPanel panel = new JPanel();



//      table.setDefaultEditor(Object.class,new MyEditor());

      table.setPreferredScrollableViewportSize(new Dimension(500, 70));
      table.setFillsViewportHeight(true);

              //Create the scroll pane and add the table to it.
              JScrollPane scrollPane = new JScrollPane(table);


      panel_1.add(btnNewButton_1);
      GroupLayout gl_contentPane = new GroupLayout(contentPane);
      gl_contentPane.setHorizontalGroup(
          gl_contentPane.createParallelGroup(Alignment.LEADING)
              .addGroup(gl_contentPane.createSequentialGroup()
                  .addGroup(gl_contentPane.createParallelGroup(Alignment.TRAILING, false)
                      .addComponent(panel_1, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                      .addComponent(panel, GroupLayout.DEFAULT_SIZE, 525, Short.MAX_VALUE))
                  .addContainerGap())
      );
      gl_contentPane.setVerticalGroup(
          gl_contentPane.createParallelGroup(Alignment.LEADING)
              .addGroup(gl_contentPane.createSequentialGroup()
                  .addComponent(panel, GroupLayout.PREFERRED_SIZE, 213, GroupLayout.PREFERRED_SIZE)
                  .addPreferredGap(ComponentPlacement.RELATED, 61, Short.MAX_VALUE)
                  .addComponent(panel_1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
      );
      GroupLayout gl_panel = new GroupLayout(panel);
      gl_panel.setHorizontalGroup(
          gl_panel.createParallelGroup(Alignment.LEADING)
              .addGroup(gl_panel.createSequentialGroup()
                  .addGap(11)
                  .addComponent(scrollPane, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                  .addContainerGap(12, Short.MAX_VALUE))
      );
      gl_panel.setVerticalGroup(
          gl_panel.createParallelGroup(Alignment.LEADING)
              .addGroup(gl_panel.createSequentialGroup()
                  .addGap(5)
                  .addComponent(scrollPane, GroupLayout.DEFAULT_SIZE, 197, Short.MAX_VALUE)
                  .addContainerGap())
      );
      panel.setLayout(gl_panel);
      contentPane.setLayout(gl_contentPane);



  }
}

Here is Job

public class Job {
    public int time = 500; // Should n't this be a long?
    public String jobName;
    public boolean processed = false;

    public Job(int time, String jobName) {
        this.time = time;
        this.jobName = jobName;
    }

    public boolean isProcessed() {
        return processed;
    }
}

And here is Your TableModel, it is optimizable, but will work...

class MyTableModel extends AbstractTableModel {
    private static final long serialVersionUID = 1L;
    private final List<Job> objects = new ArrayList<Job>();
    private final String[] columnNames = { "Nome Job", "Durata", "processed" };

    private final Class<?>[] metaModell = new Class[]{String.class, Integer.class, Boolean.class};

    public int getColumnCount() {
        return columnNames.length;
    }

    public int getRowCount() {
        return objects.size();
    }

    @Override
    public String getColumnName(int col) {
        return columnNames[col];
    }

    public Object getValueAt(int row, int col) {
        if (row >= objects.size()) 
            return null;
        Job job = getRow(row);
        switch (col) {
            case 0:
                return job.jobName;
            case 1:
                return job.time;
            case 2:
                return job.isProcessed();
        }
        return null;
    }

    private Job getRow(int row) {
        return objects.get(row);
    }

    @Override
    public Class<?> getColumnClass(int c) {
        if (c < metaModell.length)
            return metaModell[c];
        return Object.class;
    }

    @Override
    public boolean isCellEditable(int row, int col) {
        return col >= 0 && col < columnNames.length;
    }

    @Override
    public void setValueAt(Object value, int row, int col) {
        Job job = getRow(row);
        switch (col) {
            case 0:
                job.jobName = (String) value;
                break;
            case 1:
                job.time = (Integer) value;
                break;
//          case 2:
//              job.processed = (Boolean) value;
//              break;
        }
        fireTableDataChanged();
    }

    public List<Job> getJobs() {
        return objects;
    }

    public void addRow(Job job) {
        this.objects.add(job);
        fireTableDataChanged();
    }
}

As you will see I deleted all MyEditor stuff and the complicated getValues from editor stuff. I instead added a method addJob() and getJobs to the table model.

Answer 2

Okay your class do define a CellEditor, but it doesn't do anything the DefaultEditor wouldn't do.

In addition, you do not glue it together. Your JTable does not know which CellEditor it should use. You have to tell your table to use your implementation of the editor. There are multiple ways to do so (e.g. to set a default renderer for a class, which is returned by your tablemodel). You can also assign a CellEditor directly to the column ( column.setCellEditor(new MyCellEditor()); --> http://docs.oracle.com/javase/tutorial/uiswing/components/table.html)