我发布了Java TableModelListener和Live FeedListener的答案?,但我收到– kleopatra的评论
nonono - you never change the notifier in receiving a change event. As to probable effects, think: nasty loops. As to code sanity, think: indecent intimacy. It's the task of the model itself to internally update related values if necessary.
可以告诉我什么是更改通知者,接收更改事件,可能发生的情况,她真正的意思,因为当我尝试所有我知道我只从非常快的循环中收到RepaintManager异常的事情时,
我再也没有例外
我将其乘以50 x 1000矩阵,
使用prepareRenderer(更改正/负值的颜色)
刷新率175毫秒
代码演示了如何更改通知程序和另外两种(可能是正确的)方式
import java.awt.*; import java.awt.event.ActionEvent; import java.util.Random; import java.util.concurrent.*; import javax.swing.*; import javax.swing.event.*; import javax.swing.table.DefaultTableModel; public class ChangeNotifiersOnEvent extends JFrame implements Runnable { private static final long serialVersionUID = 1L; private boolean runProcess = true; private Random random = new Random(); private javax.swing.Timer timerRun; private Executor executor = Executors.newCachedThreadPool(); private String[] columnNames = {"Source", "Hit", "Last", "Ur_Diff"}; private JTable table; private Object[][] data = {{"Swing Timer", 2.99, 5, 1.01}, {"Swing Worker", 7.10, 5, 1.010}, {"TableModelListener", 25.05, 5, 1.01}}; private DefaultTableModel model = new DefaultTableModel(data, columnNames); public ChangeNotifiersOnEvent() { table = new JTable(model) { private static final long serialVersionUID = 1L; @Override public Class getColumnClass(int column) { return getValueAt(0, column).getClass(); } }; model.addTableModelListener(new TableModelListener() { @Override public void tableChanged(TableModelEvent tme) { if (tme.getType() == TableModelEvent.UPDATE) { if (tme.getColumn() == 1 && tme.getLastRow() == 2) { double dbl = ((Double) table.getModel().getValueAt(2, 1)) - ((Integer) table.getModel().getValueAt(2, 2)); table.getModel().setValueAt(dbl, 2, 3); } else if (tme.getColumn() == 1 && tme.getLastRow() == 0) { prepareUpdateTableCell(); } else if (tme.getColumn() == 1 && tme.getLastRow() == 1) { executor.execute(new MyTask(MyTask.UPDATE_TABLE_COLUMN)); } } } }); table.setRowHeight(30); table.setFont(new Font("Serif", Font.BOLD, 20)); table.getColumnModel().getColumn(0).setPreferredWidth(180); table.setPreferredScrollableViewportSize(table.getPreferredSize()); JScrollPane scrollPane = new JScrollPane(table); add(scrollPane, BorderLayout.CENTER); new Thread(this).start(); } private void prepareUpdateTableCell() { timerRun = new javax.swing.Timer(10, UpdateTableCell()); timerRun.setRepeats(false); timerRun.start(); } private Action UpdateTableCell() { return new AbstractAction("Update Table Cell") { private static final long serialVersionUID = 1L; @Override public void actionPerformed(ActionEvent e) { double dbl = ((Double) table.getModel().getValueAt(0, 1)) - ((Integer) table.getModel().getValueAt(0, 2)); table.getModel().setValueAt(dbl, 0, 3); } }; } @Override public void run() { while (runProcess) { try { Thread.sleep(250); } catch (Exception e) { e.printStackTrace(); } changeTableValues(); } } private void changeTableValues() { Runnable doRun = new Runnable() { @Override public void run() { table.getModel().setValueAt(random.nextInt(128) + random.nextDouble(), 0, 1); table.getModel().setValueAt(random.nextInt(256) + random.nextDouble(), 1, 1); table.getModel().setValueAt(random.nextInt(512) + random.nextDouble(), 2, 1); table.getModel().setValueAt(random.nextInt(128), 0, 2); table.getModel().setValueAt(random.nextInt(128), 1, 2); table.getModel().setValueAt(random.nextInt(128), 2, 2); } }; SwingUtilities.invokeLater(doRun); } private class MyTask extends SwingWorker<Void, Integer> { private static final String UPDATE_TABLE_COLUMN = "update"; private String namePr; private double dbl; MyTask(String str) { this.namePr = str; } @Override protected Void doInBackground() throws Exception { dbl = ((Double) table.getModel().getValueAt(1, 1)) - ((Integer) table.getModel().getValueAt(1, 2)); return null; } @Override protected void done() { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { table.getModel().setValueAt(dbl, 1, 3); } }); } } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { ChangeNotifiersOnEvent frame = new ChangeNotifiersOnEvent(); frame.setDefaultCloseOperation(EXIT_ON_CLOSE); frame.setLocation(150, 150); frame.pack(); frame.setVisible(true); } }); } }
我认为她的意思是,如果您不真正考虑代码,那么可以引入无限循环。
大多数人在创建表时可能会使第1列,第2列可编辑,使第3列不可编辑,因为第3列仅是两列之间的区别。
因此,当他们编写TableModelListener时,他们将检查UPDATE事件,但忘记检查以查看更新了哪一列,因为他们认为该表不允许他们更新第3列。
他们忘记了,当TableModelListener更新第3列时,将生成另一个UPDATE事件,从而导致无限循环。当然,像您的示例一样,适当的编码将防止循环。
通常,它不应引起异常。
第二点是关于业务规则。业务规则应在一个地方定义,在这种情况下为模型。数据本身和数据更新应在一个地方进行。