从java中的jtable单元获取最新值 [英] get latest value from jtable cell in java
问题描述
有人可以在下面举例说明问题: 我有一个像下面的jtable
Can someone give an example of question below: I have a jtable like below
plus | minus | total
10 | 0 | 10
0 | 2 | 8
0 | 3 | 5
如何获取最新的total(5)的值,以便可以在公式中再次使用它 总数=总数+负号?另外,由于加号和减号会不断添加,因此total的值将保持更新.
How can I get the value of latest total(5) so I can use it again in formula total=total+plus-minus? Also the value of total will keep updated because of plus and minus will be added continuously.
推荐答案
有人可以在下面举例说明问题吗?
Can someone give an example of question below:
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);
}
});
}
}
.
通知
正确的方法只是使用 AbstractTableModel (最容易在DefaultTableModel
中覆盖此事件),在那里覆盖getValueAt()
,
proper of ways is only usage of AbstractTableModel (easiest as override this event in DefaultTableModel
), there to override getValueAt()
,
内部getValueAt()
仅计算所需列的适当公式
inside getValueAt()
only calculate proper formula for desired column
我将禁用JTable.getTableHeader().setReorderingAllowed(false);
,否则必须
I'd be disable JTable.getTableHeader().setReorderingAllowed(false);
, otherwise have to setModelIndex or before calculations
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