在 JFrame 中显示 JTable
我想做什么:
我想列出数据库的一些记录.此列表应显示在 JFrame 弹出窗口中.
I want to list some records of a database. This list should be displayed in a JFrame popup.
说明:
我有 3 个课程:
- Main.java(运行程序)
- PeopleTableModel.java(保存数据,扩展 AbstractTableModel)
- PeopleTable.java(保存逻辑,扩展 JTable)
为什么在将 JFrame 设置为可见时出现 ArrayIndexOutOfBoundsException?
Why I am getting an ArrayIndexOutOfBoundsException when setting my JFrame to visible?
更新:
似乎只有在我使用自己的 PeopleTable 类时才会出现此错误.当我将表分配给普通的 JTable 时,它可以工作.
It seems like this error only shows up, when I use my own PeopleTable class. When I assign the table to just a normal JTable, it works.
这是我得到的堆栈跟踪:
Here is my stack trace I am getting:
java.lang.ArrayIndexOutOfBoundsException: 0 >= 0
at java.util.Vector.elementAt(Vector.java:470)
at javax.swing.table.DefaultTableColumnModel.getColumn(DefaultTableColumnModel.java:294)
at javax.swing.JTable.getCellRect(JTable.java:2969)
at javax.swing.plaf.basic.BasicTableUI.createTableSize(BasicTableUI.java:1694)
at javax.swing.plaf.basic.BasicTableUI.getPreferredSize(BasicTableUI.java:1733)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1660)
at javax.swing.ScrollPaneLayout.preferredLayoutSize(ScrollPaneLayout.java:495)
at java.awt.Container.preferredSize(Container.java:1788)
at java.awt.Container.getPreferredSize(Container.java:1773)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:719)
at java.awt.Container.preferredSize(Container.java:1788)
at java.awt.Container.getPreferredSize(Container.java:1773)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at javax.swing.JRootPane$RootLayout.preferredLayoutSize(JRootPane.java:917)
at java.awt.Container.preferredSize(Container.java:1788)
at java.awt.Container.getPreferredSize(Container.java:1773)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1662)
at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:719)
at java.awt.Container.preferredSize(Container.java:1788)
at java.awt.Container.getPreferredSize(Container.java:1773)
at java.awt.Window.pack(Window.java:809)
at ch.bs.jsd.personen.Main.main(Main.java:67)
这是我的全部代码:
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.sql.ResultSet;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;
public class Main {
public static void main(String[] args) {
ArrayList<String[]> result = new ArrayList<String[]>();
SQLConnection sql = new SQLConnection();
String OBNr = "";
String firstName = "";
String lastName = "";
String qry = "SELECT loginid,ctitle as Grad,"
+ "name+' '+firstname as SachB,"
+ "cposition as Tour,Ressort,"
+ "left(location,2) as FNr "
+ "FROM dbo.abf_muPostenAdressen "
+ "WHERE loginid LIKE '%" + OBNr + "%'"
+ "AND name LIKE '%" + lastName + "%'"
+ "AND firstname LIKE '%" + firstName + "%'";
try {
ResultSet rs = sql.getConnection().prepareStatement(qry).executeQuery();
while (rs.next()) {
result.add(new String[]{
Integer.toString(rs.getRow()),
rs.getString("loginid"),
rs.getString("Grad"),
rs.getString("SachB"),
rs.getString("Tour"),
rs.getString("Ressort"),
rs.getString("FNr")
});
}
if (result.size() != 0) {
String[] selectedData = null;
if (result.size() > 1) {
String[] title = {"#", "loginid", "Grad", "SachB", "Tour",
"Ressort", "FNr"};
TableModel model = new PeopleTableModel(title, parse_2d_array(result));
JTable table = new PeopleTable(model);
JFrame frame = new JFrame();
frame.getContentPane().add(new JScrollPane(table));
frame.setVisible(true);
while (table.getSelectedRow() != -1) {
}
selectedData = result.get(table.getSelectedRow());
frame.dispose();
} else {
selectedData = result.get(0);
}
System.out.println(join(selectedData, ", "));
}
} catch (Exception e) {
e.printStackTrace();
}
sql.closeConnection();
}
private static String join(String[] s, String delimiter) {
if (s.length == 0) {
return null;
}
StringBuilder out = new StringBuilder();
out.append(s[0]);
for (int i = 1; i < s.length; ++i) {
out.append(delimiter).append(s[i]);
}
return out.toString();
}
private static String[][] parse_2d_array(ArrayList<String[]> al) {
String[][] data = new String[al.size()][6];
for (int i = 0; i < al.size(); i++) {
data[i] = al.get(i);
}
return data;
}
}
class PeopleTableModel extends AbstractTableModel {
private static final long serialVersionUID = -1080095595481949205L;
private String[] title;
private Object[][] data;
public PeopleTableModel(String[] title, Object[][] data) {
this.title = title;
this.data = data;
}
@Override
public int getColumnCount() {
return title.length;
}
@Override
public int getRowCount() {
return data.length;
}
@Override
public Object getValueAt(int row, int col) {
return data[row][col];
}
@Override
public String getColumnName(int column) {
return title[column];
}
}
class PeopleTable extends JTable {
private static final long serialVersionUID = -1080095595481949205L;
private JTable table;
private int selectedRow = -1;
private StringBuilder pressedKeys = new StringBuilder();
private long now = 0;
private long last = 0;
public PeopleTable(TableModel model) {
table = new JTable(model);
table.addMouseListener(new java.awt.event.MouseAdapter() {
@Override
public void mouseClicked(java.awt.event.MouseEvent e) {
if (e.getClickCount() == 2) {
setSelectedRow(table.rowAtPoint(e.getPoint()));
}
}
});
table.addKeyListener(new KeyAdapter() {
@Override
public void keyTyped(KeyEvent evt) {
}
@Override
public void keyReleased(KeyEvent evt) {
}
@Override
public void keyPressed(KeyEvent evt) {
int key = evt.getKeyCode();
// add only numbers
if ((key > 47 && key < 58) || (key > 95 && key < 106)) {
last = now == 0 ? 0 : now;
now = evt.getWhen();
if (now - last > 700) {
pressedKeys = new StringBuilder();
}
pressedKeys.append(evt.getKeyChar());
int row = Integer.parseInt(pressedKeys.toString()) - 1;
table.setRowSelectionInterval(row, row);
table.scrollRectToVisible(table.getCellRect(row, 0, true));
} else if (key == KeyEvent.VK_ENTER) {
if (pressedKeys.length() == 0) {
pressedKeys.append(1);
}
setSelectedRow(Integer.parseInt(pressedKeys.toString()) - 1);
}
}
});
}
public JTable getTable() {
return table;
}
private void setSelectedRow(int i) {
selectedRow = i;
}
@Override
public int getSelectedRow() {
return selectedRow;
}
@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return false;
}
@Override
public int getColumnCount() {
return table.getColumnCount();
}
@Override
public int getRowCount() {
return table.getRowCount();
}
@Override
public Object getValueAt(int row, int col) {
return table.getValueAt(row, col);
}
}
附加问题:有没有更好的方法来实现我的目标,或者这可以说是最佳实践?
Additional question: Is there a better way to achieve my goal or could this be stated as best practise?
推荐答案
查看 JTable 教程,那里都有描述一个>
我看不出有使用
AbstractTableModel
的理由,不知道为什么要麻烦JTable
包含实数行列(最多500
/1000
&20
/50
),以DefaultTableModel代码> 而不是
I can't see there reason to use
AbstractTableModel
, no idea why bothering forJTable
contains a real number of rows & columns (up to500
/1000
&20
/50
), start withDefaultTableModel
instead或用这个AbstractTableModel
可以开始
import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.*; import javax.swing.UIManager.LookAndFeelInfo; import javax.swing.border.LineBorder; import javax.swing.event.ListSelectionEvent; import javax.swing.event.ListSelectionListener; import javax.swing.table.*; public class RemoveAddRows extends JFrame { private static final long serialVersionUID = 1L; private Object[] columnNames = {"Type", "Company", "Shares", "Price"}; private Object[][] data = { {"Buy", "IBM", new Integer(1000), new Double(80.50)}, {"Sell", "MicroSoft", new Integer(2000), new Double(6.25)}, {"Sell", "Apple", new Integer(3000), new Double(7.35)}, {"Buy", "Nortel", new Integer(4000), new Double(20.00)} }; private JTable table; private DefaultTableModel model; private javax.swing.Timer timer = null; public RemoveAddRows() { model = new DefaultTableModel(data, columnNames) { private static final long serialVersionUID = 1L; @Override public Class getColumnClass(int column) { return getValueAt(0, column).getClass(); } }; table = new JTable(model) { private static final long serialVersionUID = 1L; @Override public Component prepareRenderer(TableCellRenderer renderer, int row, int column) { Component c = super.prepareRenderer(renderer, row, column); if (isRowSelected(row) && isColumnSelected(column)) { ((JComponent) c).setBorder(new LineBorder(Color.red)); } return c; } }; ListSelectionModel rowSelMod = table.getSelectionModel(); rowSelMod.addListSelectionListener(new ListSelectionListener() { public void valueChanged(ListSelectionEvent e) { int row = table.getSelectedRow(); int col = table.getSelectedColumn(); String str = "Selected Row(s): "; int[] rows = table.getSelectedRows(); for (int i = 0; i < rows.length; i++) { str += rows[i] + " "; } str += "Selected Column(s): "; int[] cols = table.getSelectedColumns(); for (int i = 0; i < cols.length; i++) { str += cols[i] + " "; } str += "Selected Cell: " + table.getSelectedRow() + ", " + table.getSelectedColumn(); System.out.println(str); Object value = table.getValueAt(row, col); System.out.println(String.valueOf(value)); } }); table.setPreferredScrollableViewportSize(table.getPreferredSize()); JScrollPane scrollPane = new JScrollPane(table); add(scrollPane); JButton button1 = new JButton("Remove all rows"); button1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { if (model.getRowCount() > 0) { for (int i = model.getRowCount() - 1; i > -1; i--) { model.removeRow(i); } } System.out.println("model.getRowCount() --->" + model.getRowCount()); } }); JButton button2 = new JButton("Add new rows"); button2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { start(); } }); JPanel southPanel = new JPanel(); southPanel.add(button1); southPanel.add(button2); add(southPanel, BorderLayout.SOUTH); } private void start() { timer = new javax.swing.Timer(2500, updateCol()); timer.start(); } public Action updateCol() { return new AbstractAction("text load action") { private static final long serialVersionUID = 1L; @Override public void actionPerformed(ActionEvent e) { DefaultTableModel model = (DefaultTableModel) table.getModel(); Object[] data0 = {"Buy", "IBM", new Integer(1000), new Double(80.50)}; model.addRow(data0); Object[] data1 = {"Sell", "MicroSoft", new Integer(2000), new Double(6.25)}; model.addRow(data1); Object[] data2 = {"Sell", "Apple", new Integer(3000), new Double(7.35)}; model.addRow(data2); Object[] data3 = {"Buy", "Nortel", new Integer(4000), new Double(20.00)}; model.addRow(data3); System.out.println("model.getRowCount() --->" + model.getRowCount()); timer.stop(); int rowIndex = table.getRowCount() - 1; table.changeSelection(rowIndex, 0, false, false); } }; } public static void main(String[] args) { try { for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) { System.out.println(info.getName()); if ("Nimbus".equals(info.getName())) { UIManager.setLookAndFeel(info.getClassName()); break; } } } catch (UnsupportedLookAndFeelException e) { // handle exception } catch (ClassNotFoundException e) { // handle exception } catch (InstantiationException e) { // handle exception } catch (IllegalAccessException e) { // handle exception } javax.swing.SwingUtilities.invokeLater(new Runnable() { @Override public void run() { RemoveAddRows frame = new RemoveAddRows(); frame.setDefaultCloseOperation(EXIT_ON_CLOSE); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } }
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