Multiple selection in JTable

Question

Hi ,
The problem is to select multiple rows and columns in the JTable like that of a excel application and have the focus on the first column of the last row. for example if select cells from ( 1,1 ) to ( 4,4), after selection the focus should be in cell (4,1). i have written a prgram( which is below) which uses listSelection to find out the cells which are selected. i found out the cells which are selected also. but i do not know how to get the focus on that cell. i have attached the code below also.. i want to know whether there is any method which set the focus to the particular cell. Can the problem above can be solved in any other way..or a simpler way..
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
class myTable {
public static void main(String a[] ) {
          JFrame myframe = new JFrame();
          JTable jtable = new JTable(10,10);
          jtable.setCellSelectionEnabled(true);
     // add the listener to the table
ListSelectionModel listSelectionModel;
     OSSTableSelectionHandler obj = new OSSTableSelectionHandler(jtable,10,10);
     listSelectionModel = jtable.getSelectionModel();
listSelectionModel.addListSelectionListener(obj);
     myframe.getContentPane().add(jtable);
     myframe.show();
} // end of public static void main
} // end of class of myTable
class OSSTableSelectionHandler implements ListSelectionListener {
               JTable table;
     int row;
               int col;
OSSTableSelectionHandler(JTable tab, int r, int c ) {
     table = tab;
row = r;
          col = c;
public void valueChanged(ListSelectionEvent e) {
ListSelectionModel lsm = (ListSelectionModel)e.getSource();
               int i = 0,j = 0;
int firstIndex = e.getFirstIndex();
int lastIndex = e.getLastIndex();
boolean isAdjusting = e.getValueIsAdjusting();
if (lsm.isSelectionEmpty()) {
System.out.println(" Selection empty ");
} else {
// Find out which indexes are selected.
                    int maxrow = 0 ;
int minIndex = lsm.getMinSelectionIndex();
int maxIndex = lsm.getMaxSelectionIndex();
for ( i = minIndex; i <= maxIndex; i++) {
if (lsm.isSelectedIndex(i)) {
                              if ( maxrow < i )
                                   maxrow = i;
                              for (j = 0;j < col ;j++ )
                                   if ( table.isCellSelected(i,j) )
                                        System.out.println("The selected index is " + i + " " + j);
                         } // end of if                    
} // end of for
               // after this maxrow contains the last row that has beeb selected
               // this for loop is to find out the first column in the maxrow that is selected
               for (j = 0;j < col ;j ++ )
                    if ( table.isCellSelected(maxrow,j) )
                              break;
               // set the focus to the column ( maxrow, j )
} // end of else
} // end of fucn value changed
} // end of class OSSTableSelectionHandler

Answer 1

Whic cell is focused depends on where you begin your selection. The cell that you press your mouse first will be the focused one. Here is how I implement the mutiple selection functionality in a JTable as what MS Excel provides. This class is independent of my any other package. your table has to have column headers and a upper left JLabel corner(int the scroll pane containing the table) in order to make this class which I named TableSelectionAdapter function properly. You can revise and imporve it as you need, however.
package petrochina.riped.gui.table.tableadapter;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
import java.awt.datatransfer.*;
import java.util.*;
* Enables multiple selection funtionality on <code>JTable</code>s.
* @author Guanglin Du,SEC of Riped, PetroChina,
* [email protected]
* @version 1.0 2002/09/16
public class TableSelectionAdapter extends MouseAdapter {
private String newline = "\n";
private boolean DEBUG = false;
// private boolean DEBUG = true;
private JTable myTable = null;
private boolean shiftKeyDown = false;
private boolean ctrlKeyDown = false;
private int firstSelectedColIndex = -1;
* Constructs with a <code>myTable</code> to simplify its reusability.
* Guanglin Du, 2002/09/19
* @param myTable     a <code>JTable</code>
public TableSelectionAdapter(JTable myTable) {      
this.myTable = myTable;
initTableSelection();
* The initTableSelection method: initializes the row/column/cell
* selection functionality of the table.
* Guanglin Du, 2002/09/19
public void initTableSelection() {      
getMyTable().setSelectionMode(
          ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
     //Cell selection
     myTable.addMouseListener(new MouseAdapter() {
     public void mousePressed(MouseEvent e) {
          myTable.setColumnSelectionAllowed(true);
          myTable.setRowSelectionAllowed(true);
     setMyKeyListener(); //shift/control key listener
     //column selection functionality
     JTableHeader myTableHeader = getMyTable().getTableHeader();
     myTableHeader.addMouseListener(new TableHeaderListener());
     //enalbles select-all functionality
     setSelectAllFunction();
* This setSelectAllFunction isto set the select-all functionality
* when the upper left corner label of the JTable is clicked.
* Note: JTable's parent JScrollPane has to be found.
* Guanglin Du, 2002/09/19
public void setSelectAllFunction() {      
Container firstParent = getMyTable().getParent();
if (firstParent instanceof JViewport) {
     Container secondParent = firstParent.getParent();
     if (secondParent instanceof JScrollPane) {
     JScrollPane myScrollPane = (JScrollPane)secondParent;
     JLabel myLabel =
          (JLabel)myScrollPane.getCorner(JScrollPane.UPPER_LEFT_CORNER );
     myLabel.addMouseListener(this);
* Detects shift/control key state.
* DGL, 2002/09/18
public void setMyKeyListener() {
     getMyTable().addKeyListener(new KeyAdapter(){               
     //keyPressed
     public void keyPressed(KeyEvent e){
          //shift key state
          if(e.isShiftDown())     shiftKeyDown = true;                    
          //control key state
          if(e.isControlDown()) ctrlKeyDown = true;
//keyReleased
     public void keyReleased(KeyEvent e){
          //shift key state
          if( !e.isShiftDown() ) shiftKeyDown = false;                    
          //control key state
          if( !e.isControlDown() ) ctrlKeyDown = false;
* Adds the table header listener to enable single/multiple column selection.
* DGL, 2002/09/17
public void setTableHeaderListener() {
     JTableHeader myTableHeader = myTable.getTableHeader();
     myTableHeader.addMouseListener(new TableHeaderListener());
* Returns the <code>myTable</code> property value.
* @return myTable the table that this class handles
public JTable getMyTable() {
return myTable;
* Sets <code>myTable</code> property value of this class.
* @param myTable the table that this class handles
public void setJTable(JTable myTable) {
     this.myTable = myTable;
* Returns the shiftKeyDown property value.
* @return boolean, Guanglin Du, 2002/09/18
public boolean getShiftKeyDown(){
     return shiftKeyDown;
* Return the ctrlKeyDown property value.
* @return boolean, Guanglin Du, 2002/09/18
public boolean getCtrlKeyDown(){
     return ctrlKeyDown;
* This inner class handles the column selection, the same
* behavior as MS Excel.
* Guanglin Du, 2002/09/18
class TableHeaderListener extends MouseAdapter {
public void mousePressed(MouseEvent e) {    
     stopLatestCellEditing(); //To save the data being edited
     if(DEBUG) System.out.print("mousePressed on ");
     JTableHeader myColumnHeader = (JTableHeader)e.getSource();
     Point myPoint = e.getPoint();
     int selectedColIndex = myColumnHeader.columnAtPoint(myPoint);
     if(DEBUG) System.out.print("the header of column "
          + selectedColIndex+newline);
     JTable table = myColumnHeader.getTable();
     //The following column selection methods work only if these
     //properties are set this way
     table.setColumnSelectionAllowed(true);
     table.setRowSelectionAllowed(false);
     int myRowCount = table.getRowCount();
     //makes this table focused, so that setMyKeyListener method can
     //listen for shift/control KeyEvent
     table.requestFocus();
//     System.out.println("myRowCount = " + myRowCount);
     if( getShiftKeyDown() ){
     table.clearSelection();
     table.setRowSelectionInterval(0,myRowCount-1);
     table.setColumnSelectionInterval(selectedColIndex,selectedColIndex);
     if(firstSelectedColIndex > -1) {
          table.addColumnSelectionInterval(firstSelectedColIndex, selectedColIndex);
          firstSelectedColIndex = -1;//restore to -1
     } else if( getCtrlKeyDown() ) {
     table.addRowSelectionInterval(0,myRowCount-1);
     table.addColumnSelectionInterval(selectedColIndex,selectedColIndex);
     } else {
     table.clearSelection();
     table.setRowSelectionInterval(0,myRowCount-1);
     table.setColumnSelectionInterval(selectedColIndex,selectedColIndex);
     if(DEBUG) System.out.println("shiftKeyDown = " + shiftKeyDown
          +";"+" ctrlKeyDown = " + ctrlKeyDown);     
     //saves the first selected column index
     firstSelectedColIndex = selectedColIndex;
* MouseAdapter implemenation.
* mousePressed: sets the select-all functionality
* when upper left corner label of the table is clicked
* Guanglin Du, 2002/09/18
public void mousePressed(MouseEvent e) {    
     if(DEBUG) System.out.println("Select all");
     stopLatestCellEditing();//To save the data in editing
     getMyTable().selectAll();
* Triggers the latest <code>ActionEvent</code> in a table cell to save
* the latest data. Or, the newly input data will not be stored into the table
* model and cannot be retrieved.
public void stopLatestCellEditing() {
int editingRow = getMyTable().getEditingRow();
int editingCol = getMyTable().getEditingColumn();
if (editingRow != -1 && editingCol != -1){
     TableCellEditor cellEditor =
     getMyTable().getCellEditor(editingRow, editingCol);
     cellEditor.stopCellEditing();
Here is how you can use it in your coding(where myTable is a JTable instance you create):
     /* Adds TableSelectionAdapter to enable all kinds of selection action. */
     TableSelectionAdapter tableSelect = new TableSelectionAdapter(myTable);