public void mousePressed(MouseEvent event) {
                    if (event.getButton() == MouseEvent.BUTTON3) {
                         Point point = event.getPoint();
                         int column = table.columnAtPoint(point);
                         int row = table.rowAtPoint(point);
                         if(table.isRowSelected(row)==true)
                         {
                             table.removeColumnSelectionInterval(column, column);
                             table.removeRowSelectionInterval(row, row); 
                         }
                         else
                         {
                         table.addColumnSelectionInterval(column, column);
                         table.addRowSelectionInterval(row, row);
                         
                         } //end else
                    }
               }

import javax.swing.JTable;
import javax.swing.ListSelectionModel;

class MJTable extends JTable {

	public MJTable() {
	    super();
	    
	  }
	// переопределяем для выделения левой кнопкой мыши графиков
	@Override
    public void changeSelection(int rowIndex, int columnIndex, boolean toggle, boolean extend) {
        int latestClickedRowIndex = rowIndex;
        ListSelectionModel selectionModel = getSelectionModel();
        boolean selected = selectionModel.isSelectedIndex(rowIndex);
        //throw new UnsupportedOperationException("Paila.");
        if (selected) {
            selectionModel.removeSelectionInterval(rowIndex, rowIndex);
            getValueAt(rowIndex, columnIndex);
        } else {
            selectionModel.addSelectionInterval(rowIndex, rowIndex);
        }
    }

	
}