Java:在后台更新包含大量行的JTable

我正在编写一个简单的Java Swing实用程序,它将从MQ JMS服务器读取消息并将它们显示在JTable中.

private void getMessages() {
        try {
            if (null != Queue) {
                Queue.close();  //Close previous queue connection if there is one.
            }
            Queue = new MQQueue(QueueManager, tableQueues.getValueAt(tableQueues.getSelectedRow(), 1).toString(), MQConstants.MQOO_INPUT_SHARED | MQConstants.MQOO_BROWSE | MQConstants.MQOO_OUTPUT, queueManager, null, null);
            int count = 0;
            modelMessages.setRowCount(0);
            MQGetMessageOptions getOptions = new MQGetMessageOptions();
            getOptions.options = MQConstants.MQGMO_BROWSE_FIRST;
            ArrayList rows = new ArrayList();
            while(true) {
                if (count > 0) {
                    getOptions.options = MQConstants.MQGMO_BROWSE_NEXT;
                }
                MQMessage message = new MQMessage();
                try {
                    Queue.get(message, getOptions);
                    byte[] b = new byte[message.getMessageLength()];
                    message.readFully(b);
                    rows.add(new Object[]{count + 1, new String(b)});
                    modelMessages.addRow(new Object[]{count + 1, new String(b)});
                    message.clearMessage();
                    count++;
                }
                catch (IOException e) {
                    break;
                }
                catch (MQException e) {
                    if (e.completionCode == 2 && e.reasonCode == MQConstants.MQRC_NO_MSG_AVAILABLE) {
                        break;
                    }
                }
            }
            modelMessages.fireTableDataChanged();
        } catch (MQException e) {
            txtMessage.setText("MQJE001: Completion Code '" + e.completionCode + "', Reason '" + e.reasonCode + "'.");
            modelMessages.setRowCount(0);
            modelMessages.fireTableDataChanged();
        }
    }

这非常适用于较小的队列,但对于大型的队列,它需要一段时间来填充这个表,并在此期间,Swing应用程序被冻结,所以我调查的方式来填充JTable的背景,同时保持不只是应用程序,但JTable中本身可以使用和滚动.

我对线程并不是很熟悉,我尝试了一些东西,例如在SwingUtilities.invokeLater中包装一些部分并实现doInBackground(),但似乎没有任何工作.有人可以指出我正确的方向如何继续这个？

编辑

根据以下回复,以下是解决方案:

public class GetMessagesWorker extends SwingWorker {

    //http://stackoverflow.com/questions/22072480/java-updating-jtable-with-lots-of-rows-in-the-background#

    private final DefaultTableModel model;

    public GetMessagesWorker(DefaultTableModel model){
        this.model = model;
    }

    @Override
    protected DefaultTableModel doInBackground() throws Exception {
        try {
            if (null != Queue) {
                Queue.close();  //Close previous queue connection if there is one.
            }
            Queue = new MQQueue(QueueManager, tableQueues.getValueAt(tableQueues.getSelectedRow(), 1).toString(), MQConstants.MQOO_INPUT_SHARED | MQConstants.MQOO_BROWSE | MQConstants.MQOO_OUTPUT, queueManager, null, null);
            int count = 0;
            modelMessages.setRowCount(0);
            MQGetMessageOptions getOptions = new MQGetMessageOptions();
            getOptions.options = MQConstants.MQGMO_BROWSE_FIRST;
            while(true) {
                if (count > 0) {
                    getOptions.options = MQConstants.MQGMO_BROWSE_NEXT;
                }
                MQMessage message = new MQMessage();
                try {
                    Queue.get(message, getOptions);
                    byte[] b = new byte[message.getMessageLength()];
                    message.readFully(b);
                    Object[] row = {count + 1, new String(b)};
                    publish(row);
                    message.clearMessage();
                    count++;
                    if (isCancelled()) {
                        modelMessages.setRowCount(0);
                        count = 0;
                        message.clearMessage();
                        return model;
                    }
                }
                catch (IOException e) {
                    break;
                }
                catch (MQException e) {
                    if (e.completionCode == 2 && e.reasonCode == MQConstants.MQRC_NO_MSG_AVAILABLE) {
                        break;
                    }
                }
            }
            //modelMessages.fireTableDataChanged();
        } catch (MQException e) {
            txtMessage.setText("MQJE001: Completion Code '" + e.completionCode + "', Reason '" + e.reasonCode + "'.");
            modelMessages.setRowCount(0);
            modelMessages.fireTableDataChanged();
        }
        return model;
    }

    @Override
    protected void process(List chunks){
        for(Object[] row : chunks){
            model.addRow(row);
        }
    }

}

这是听众:

    tableQueues = new JTable(modelQueues);
    tableQueues.getSelectionModel().addListSelectionListener(new ListSelectionListener() {
        public void valueChanged(ListSelectionEvent e) {
            if (!e.getValueIsAdjusting()) {
                txtMessage.setText("");
                if (tableQueues.getSelectedRow() > -1) {
                    gmw.cancel(false);
                    gmw = new GetMessagesWorker(modelMessages);
                    gmw.execute();
                }
            }
        }
    });

Aaron Digull.. 5

在Swing中进行线程化时,您需要了解必须在后台线程中完成工作,但任何UI更新都必须在Swing线程中完成.

这意味着您应该创建一个线程来获取消息.如果您有一个(或更多),则使用SwingUtilities与Swing线程同步并更新表.

在上面的代码段,这意味着你需要使用SwingUtilities每次您调用的方法时间modelMessages,txtMessage等等.

由于这非常昂贵,你通常会在列表中收集10个新行,然后使用一次调用将它们一次性添加SwingUtilities.invokeLater().