Question

我在JForm中创建了一个Jtable，它显示了来自多个表的ResultSet。像魅力一样工作，但表扩展到我的所有JForm，我需要有两个按钮，表自动隐藏它们。 enter image description here 如何编辑它以便jtable不覆盖我的底部按钮？提前谢谢。

package start;
import java.awt.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
/**
 *
 * @author Notebook
 */
public class TableFromMySqlDatabase extends JFrame
{
    public TableFromMySqlDatabase()
    {
        ArrayList columnNames = new ArrayList();
        ArrayList data = new ArrayList();

        //  Connect to an MySQL Database, run query, get result set
        String url = "jdbc:mysql://localhost:3306/project";
        String userid = "root";
        String password = "";
        String sql = 
"SELECT\n" +
"r.idRentals,\n" +
"c.idCustomer,\n" +
"c.CustomerName,\n" +
"m.idMovie,\n" +
"m.TitleMovie,\n" +
"r.RentedDate\n" +
"\n" +
"FROM rentals AS r\n" +
"INNER JOIN customer AS c ON r.Customer_idCustomer = c.idCustomer\n" +
"INNER JOIN rental_movie AS rm ON rm.Rentals_idRentals = r.idRentals\n" +
"INNER JOIN movie AS m ON  rm.Movie_idMovie = m.idMovie\n" +
";";

        // Java SE 7 has try-with-resources
        // This will ensure that the sql objects are closed when the program 
        // is finished with them
        try (Connection connection = DriverManager.getConnection( url, userid, password );
            Statement stmt = connection.createStatement();
            ResultSet rs = stmt.executeQuery( sql ))
        {
            ResultSetMetaData md = rs.getMetaData();
            int columns = md.getColumnCount();

            //  Get column names
            for (int i = 1; i <= columns; i++)
            {
                columnNames.add( md.getColumnName(i) );
            }

            //  Get row data
            while (rs.next())
            {
                ArrayList row = new ArrayList(columns);

                for (int i = 1; i <= columns; i++)
                {
                    row.add( rs.getObject(i) );
                }

                data.add( row );
            }
        }
        catch (SQLException e)
        {
            System.out.println( e.getMessage() );
        }

        // Create Vectors and copy over elements from ArrayLists to them
        // Vector is deprecated but I am using them in this example to keep 
        // things simple - the best practice would be to create a custom defined
        // class which inherits from the AbstractTableModel class
        Vector columnNamesVector = new Vector();
        Vector dataVector = new Vector();

        for (int i = 0; i < data.size(); i++)
        {
            ArrayList subArray = (ArrayList)data.get(i);
            Vector subVector = new Vector();
            for (int j = 0; j < subArray.size(); j++)
            {
                subVector.add(subArray.get(j));
            }
            dataVector.add(subVector);
        }

        for (int i = 0; i < columnNames.size(); i++ )
            columnNamesVector.add(columnNames.get(i));

        //  Create table with database data    
        JTable table = new JTable(dataVector, columnNamesVector)
        {
            public Class getColumnClass(int column)
            {
                for (int row = 0; row < getRowCount(); row++)
                {
                    Object o = getValueAt(row, column);

                    if (o != null)
                    {
                        return o.getClass();
                    }
                }

                return Object.class;
            }
        };

//
        JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );

        JPanel buttonPanel = new JPanel();
        getContentPane().add( buttonPanel, BorderLayout.SOUTH);


    }

    public static void main(String[] args)
    {

        TableFromMySqlDatabase frame = new TableFromMySqlDatabase();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible(true);
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jScrollPane1 = new javax.swing.JScrollPane();
        jTable1 = new javax.swing.JTable();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jScrollPane1.setBorder(javax.swing.BorderFactory.createEtchedBorder());
        jScrollPane1.setAutoscrolls(true);

        jTable1.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0), 1, true));
        jTable1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {
                {null, null, null, null},
                {null, null, null, null},
                {null, null, null, null},
                {null, null, null, null}
            },
            new String [] {
                "Title 1", "Title 2", "Title 3", "Title 4"
            }
        ));
        jTable1.setAutoscrolls(false);
        jTable1.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
        jTable1.setDebugGraphicsOptions(javax.swing.DebugGraphics.LOG_OPTION);
        jTable1.setFillsViewportHeight(true);
        jScrollPane1.setViewportView(jTable1);

        jButton1.setText("Return");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton2.setText("Rent");
        jButton2.setAutoscrolls(true);
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addGap(50, 50, 50)
                .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 93, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(77, 77, 77)
                .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 92, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 441, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(34, 34, 34)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 128, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 135, Short.MAX_VALUE)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(4, 4, 4)
                        .addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
                .addContainerGap())
        );

        pack();
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
    }                                        

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
    }                                        



    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    // End of variables declaration                   
}

Answer 1

您发布的代码没有任何意义。它似乎是由IED生成的代码和您手动添加的代码的组合。

    JPanel buttonPanel = new JPanel();
    getContentPane().add( buttonPanel, BorderLayout.SOUTH);

从我可以看到你创建一个面板但不向面板添加任何按钮。也许您稍后添加按钮。如果是这样，那么你需要使用：

panel.add(...);
panel.revalidate();
panel.repaint();

确保调用布局管理器并以新的大小/位置绘制组件。

此外，使用SQL时，使用PreparedStantement会更容易，这将使SQL语句正确分隔。一个基本的例子：

String sql =“INSERT INTO Page（Name，Title）VALUES（？，？）”;

PreparedStatement stmt = connection.prepareStatement(sql);

stmt.setString( 1, "Name1" );
stmt.setString( 2, "Title1" );
System.out.println(stmt);
stmt.executeUpdate();

JTable正在掩盖按钮，布局编辑中需要帮助

1 个答案: