Java Swing实现JTable检测单元格数据变更事件的方法示例

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IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */package awtDemo;/* * TableDemo.java requires no other files. */import javax.swing.AbstractAction;import javax.swing.Action;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTable;import javax.swing.table.AbstractTableModel;import java.awt.Dimension;import java.awt.GridLayout;import java.awt.event.ActionEvent;/**  * TableDemo is just like SimpleTableDemo, except that it * uses a custom TableModel. */@SuppressWarnings("serial")public class TableDemo extends JPanel {  private boolean DEBUG = false;  @SuppressWarnings("unused") public TableDemo() {    super(new GridLayout(1,0));    JTable table = new JTable(new MyTableModel());    table.setPreferredScrollableViewportSize(new Dimension(500, 70));    table.setFillsViewportHeight(true);    //Create the scroll pane and add the table to it.    JScrollPane scrollPane = new JScrollPane(table);    //Add the scroll pane to this panel.    add(scrollPane);    Action action = new AbstractAction()    {      public void actionPerformed(ActionEvent e)      {        TableCellListener tcl = (TableCellListener)e.getSource();        System.out.printf("cell changed%n");        System.out.println("Row  : " + tcl.getRow());        System.out.println("Column: " + tcl.getColumn());        System.out.println("Old  : " + tcl.getOldValue());        System.out.println("New  : " + tcl.getNewValue());      }    };    TableCellListener tcl = new TableCellListener(table, action);  }  class MyTableModel extends AbstractTableModel {    private String[] columnNames = {"First Name",                    "Last Name",                    "Sport",                    "# of Years",                    "Vegetarian"};    private Object[][] data = {    {"Kathy", "Smith",     "Snowboarding", new Integer(5), new Boolean(false)},    {"John", "Doe",     "Rowing", new Integer(3), new Boolean(true)},    {"Sue", "Black",     "Knitting", new Integer(2), new Boolean(false)},    {"Jane", "White",     "Speed reading", new Integer(20), new Boolean(true)},    {"Joe", "Brown",     "Pool", new Integer(10), new Boolean(false)}    };    public int getColumnCount() {      return columnNames.length;    }    public int getRowCount() {      return data.length;    }    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.     */    @SuppressWarnings({ "unchecked", "rawtypes" }) 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.      if (col < 2) {        return false;      } else {        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.   */  private static void createAndShowGUI() {    //Create and set up the window.    JFrame frame = new JFrame("TableDemo - www.VeVB.COm");    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    //Create and set up the content pane.    TableDemo newContentPane = new TableDemo();    newContentPane.setOpaque(true); //content panes must be opaque    frame.setContentPane(newContentPane);    //Display the window.    frame.pack();    frame.setVisible(true);  }  public static void main(String[] args) {    //Schedule a job for the event-dispatching thread:    //creating and showing this application's GUI.    javax.swing.SwingUtilities.invokeLater(new Runnable() {      public void run() {        createAndShowGUI();      }    });  }}

package awtDemo;import java.awt.event.*;import javax.swing.*;import java.beans.*;/* * This class listens for changes made to the data in the table via the * TableCellEditor. When editing is started, the value of the cell is saved * When editing is stopped the new value is saved. When the oold and new * values are different, then the provided Action is invoked. * * The source of the Action is a TableCellListener instance. */public class TableCellListener implements PropertyChangeListener, Runnable{  private JTable table;  private Action action;  private int row;  private int column;  private Object oldValue;  private Object newValue;  /**   * Create a TableCellListener.   *   * @param table  the table to be monitored for data changes   * @param action the Action to invoke when cell data is changed   */  public TableCellListener(JTable table, Action action)  {    this.table = table;    this.action = action;    this.table.addPropertyChangeListener( this );  }  /**   * Create a TableCellListener with a copy of all the data relevant to   * the change of data for a given cell.   *   * @param row the row of the changed cell   * @param column the column of the changed cell   * @param oldValue the old data of the changed cell   * @param newValue the new data of the changed cell   */  private TableCellListener(JTable table, int row, int column, Object oldValue, Object newValue)  {    this.table = table;    this.row = row;    this.column = column;    this.oldValue = oldValue;    this.newValue = newValue;  }  /**   * Get the column that was last edited   *   * @return the column that was edited   */  public int getColumn()  {    return column;  }  /**   * Get the new value in the cell   *   * @return the new value in the cell   */  public Object getNewValue()  {    return newValue;  }  /**   * Get the old value of the cell   *   * @return the old value of the cell   */  public Object getOldValue()  {    return oldValue;  }  /**   * Get the row that was last edited   *   * @return the row that was edited   */  public int getRow()  {    return row;  }  /**   * Get the table of the cell that was changed   *   * @return the table of the cell that was changed   */  public JTable getTable()  {    return table;  }//// Implement the PropertyChangeListener interface//  @Override  public void propertyChange(PropertyChangeEvent e)  {    // A cell has started/stopped editing    if ("tableCellEditor".equals(e.getPropertyName()))    {      if (table.isEditing()){        //System.out.printf("tableCellEditor is editing..%n");        processEditingStarted();      }      else{        //System.out.printf("tableCellEditor editing stopped..%n");        processEditingStopped();      }    }  }  /*   * Save information of the cell about to be edited   */  private void processEditingStarted()  {    // The invokeLater is necessary because the editing row and editing    // column of the table have not been set when the "tableCellEditor"    // PropertyChangeEvent is fired.    // This results in the "run" method being invoked    SwingUtilities.invokeLater( this );  }  /*   * See above.   */  @Override  public void run()  {    row = table.convertRowIndexToModel( table.getEditingRow() );    column = table.convertColumnIndexToModel( table.getEditingColumn() );    oldValue = table.getModel().getValueAt(row, column);    //这里应对oldValue为null的情况做处理，否则将导致原值与新值均为空时仍被视为值改变    if(oldValue == null)      oldValue = "";    newValue = null;  }  /*   *  Update the Cell history when necessary   */  private void processEditingStopped()  {    newValue = table.getModel().getValueAt(row, column);    //这里应对newValue为null的情况做处理，否则后面会抛出异常    if(newValue == null)      newValue = "";    // The data has changed, invoke the supplied Action    if (! newValue.equals(oldValue))    {      // Make a copy of the data in case another cell starts editing      // while processing this change      TableCellListener tcl = new TableCellListener(        getTable(), getRow(), getColumn(), getOldValue(), getNewValue());      ActionEvent event = new ActionEvent(        tcl,        ActionEvent.ACTION_PERFORMED,        "");      action.actionPerformed(event);    }  }}