Jtable

Question

我有一个包含来自数据库的数据的 JTable。我可以使用

提取当前在 table 中的数据

table.getValueAt(table.getSelectedRow(),3)

我想不通的是如何在运行 App 中编辑后获取同一单元格的新数据。我已经尝试运行更新 SQL 命令来推送新数据，但它没有更新。我想我错过了一步。我也尝试过 TableModelListener 但我运气不好让它按我需要的那样工作。这是我目前协助检索和更新数据的内容：

private void UpdateDbFromJTable(){
    table.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
        @Override
        public void valueChanged(ListSelectionEvent event) {
            if (table.getSelectedRow() > -1) {
                // print first column value from selected row
             String App = table.getValueAt(table.getSelectedRow(),0).toString();
             String Version = table.getValueAt(table.getSelectedRow(),1).toString();
             String Issue = table.getValueAt(table.getSelectedRow(),2).toString();
             String Resolved =table.getValueAt(table.getSelectedRow(),3).toString();


            try {
                String sql = "UPDATE Bugs SET Resolved =" + Resolved + "WHERE App = \" " + App + "' AND Version =\"" + Version + "\" AND Issue = \"" + Issue + "\"";
                conn = DriverManager.getConnection(DB_URL);
                stmt = conn.prepareStatement(sql);
                rs = stmt.executeUpdate();


            } catch (Exception e) {
                JOptionPane.showMessageDialog(null, e);

            }
             }

        }

    });


}

Update 语句此时不正确，因为它只是将 "Resolved" 更新为数据库中已设置的内容。

这就是我已更正更新后发生的情况。在对不同的 table 条目进行更改后，每次单击“保存”时，我都会得到重复的 'println'(s)：私人无效 UpdateDbFromJTable(){

    table.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
        @Override
        public void valueChanged(ListSelectionEvent event) {
            String App = null;
            String Version = null;
            String Issue = null;
            String Resolved = null;
             if (! event.getValueIsAdjusting())
                {
            if (table.getSelectedRow() > -1) {
                // print first column value from selected row
                App = table.getValueAt(table.getSelectedRow(),0).toString();
                Version = table.getValueAt(table.getSelectedRow(),1).toString();
                Issue = table.getValueAt(table.getSelectedRow(),2).toString();
                Resolved =table.getValueAt(table.getSelectedRow(),3).toString();

                System.out.println(App + "  " + Version + "  " + Issue +  "  " + Resolved);
                }

                }
             if(table.isEditing()){
                    table.getCellEditor().stopCellEditing();

            try {


                conn = DriverManager.getConnection(DB_URL);
                String sql = "UPDATE Bugs SET Resolved = ? WHERE App = ? AND Version = ? AND Issue = ?";
                PreparedStatement stmt = conn.prepareStatement(sql);
                stmt.setString(1, Resolved);
                stmt.setString(2, App);
                stmt.setString(3, Version);
                stmt.setString(4, Issue);
                stmt.executeUpdate();





            } catch (Exception e) {
                JOptionPane.showMessageDialog(null, e);

            }
             }

        }

    });


}

我的保存按钮：

btnSave.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){
            UpdateDbFromJTable();
            JTable();

        }
    });

还有我的 JTable()：

Connection conn = null;
ResultSet rs = null;
PreparedStatement stmt = null;
private JTable table;
private void JTable() {
    String sql = "SELECT * FROM Bugs";
    try {
        conn = DriverManager.getConnection(DB_URL);
        stmt = conn.prepareStatement(sql);
        rs = stmt.executeQuery();
        table.setModel(DbUtils.resultSetToTableModel(rs));



    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, e);

    }


}

Answer 1

您可以尝试添加 TableModelListener 这种方式，一旦 table 发生变化就会执行。类似于：

tableModel.addTableModelListener(new TableModelListener(){
    @Override
    public void tableChanged(TableModelEvent tableModelEvent) {
        if(table.isEditing())
        String value = table.getValueAt(table.getSelectedRow(),3);    
        //do stuff  with value          
    }
});

Answer 2

我猜您的编辑器仍处于活动状态，因此数据尚未保存到模型中。

因此您需要在 ActionListener 中停止编辑：

if (table.isEditing())
     table.getCellEditor().stopCellEditing();

查看 Table Stop Editing 了解更多信息和另一种方法

此外，为您的 SQL 使用 PreparedStatment 它更易于维护且不易出错：

String sql = "UPDATE Page SET Title = ? WHERE Name = ?";

PreparedStatement stmt = connection.prepareStatement(sql);

stmt.setString( 1, "update" );
stmt.setString( 2, "Name3" );
stmt.executeUpdate();
stmt.close();

Answer 3

感谢@camickr 指出它正在创建多个侦听器，我终于弄清楚了为什么它会重复。我在按钮本身周围移动了监听器。

 table.getSelectionModel().addListSelectionListener(new ListSelectionListener() {
            @Override
            public void valueChanged(ListSelectionEvent event) {

                if (!event.getValueIsAdjusting()) {
                    if (table.getSelectedRow() > -1) {
                        // print first column value from selected row
                        app = table.getValueAt(table.getSelectedRow(), 0).toString();
                        version = table.getValueAt(table.getSelectedRow(), 1).toString();
                        issue = table.getValueAt(table.getSelectedRow(), 2).toString();
                        resolved = table.getValueAt(table.getSelectedRow(), 3).toString();
                        System.out.println(app + "  " + version + "  " + issue + "  " + resolved);

                    }
                }
                btnSave.addActionListener(new ActionListener() {
                    public void actionPerformed(ActionEvent e) {

                        updateDbFromJTable();
                        //jTable();
                    }
                });
            }
        });

Jtable - 编辑后获取 table 单元格数据

Jtable - Get table cell data after edit

java

swing