Question

我是第一次在stackexchange上提问，所以不知道如何处理它

这是我的jdialog代码，我使用jtable并从sql获取数据但每次我按下另一个jframe中的我的FIND按钮加载这个jdialog第一次显示没有重复，因为我按下按钮加载jdialog它复制相同的数据多次它显示了数据库中的名称列表

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableModel;

import java.awt.GridBagLayout;

import javax.swing.JTextField;

import java.awt.GridBagConstraints;
import java.awt.Insets;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.JTable;

import java.util.Vector;

import javax.swing.JLabel;

import java.awt.Color;


public class FindStudent extends JDialog {

    private final JPanel contentPanel = new JPanel();
    private JTextField textField;
    private JTextField textField_1;
    private JTable table;
    Connection conn = null;
    Statement stmt = null;
    static Vector<Vector<String>> data = new Vector<Vector<String>>();
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        try {
            FindStudent dialog = new FindStudent();
            dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
            dialog.setVisible(true);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Create the dialog.
     */
    public FindStudent() {
        Vector<String> columnNames = new Vector<String>();
       columnNames.add("RegNo");
       columnNames.add("StudentName");
       columnNames.add("FatherName");
       columnNames.add("Class");

        String query = "Select RegNo, StudentName, FatherName, Class from SchoolDB.dbo.StudentProfile";
        try{
            conn = DriverManager.getConnection("jdbc:sqlserver:" + "//" +
                    "localhost;1433" + "Database=SchooDB"+";integratedSecurity=true;");
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

            stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(query);
            while (rs.next()) {

                Vector<String> vstring = new Vector<String>();


                vstring.add(rs.getString("RegNo"));
                vstring.add(rs.getString("StudentName"));
                vstring.add(rs.getString("FatherName"));
                vstring.add(rs.getString("Class"));
                data.add(vstring);
        }
        }
        catch (Exception e){
            e.printStackTrace();
        }
        /*catch (SQLException e) {
            e.printStackTrace();
            }*/
        finally{
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
        }

        setBounds(100, 100, 430, 350);
        this.setAlwaysOnTop(true);
        this.setModal(true);
        getContentPane().setLayout(new BorderLayout());
        contentPanel.setBackground(Color.WHITE);
        contentPanel.setBorder(new EmptyBorder(5, 5, 5, 5));
        getContentPane().add(contentPanel, BorderLayout.CENTER);
        GridBagLayout gbl_contentPanel = new GridBagLayout();
        gbl_contentPanel.columnWidths = new int[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
        gbl_contentPanel.rowHeights = new int[]{0, 0, 35, 0};
        gbl_contentPanel.columnWeights = new double[]{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE};
        gbl_contentPanel.rowWeights = new double[]{0.0, 0.0, 0.0, Double.MIN_VALUE};
        contentPanel.setLayout(gbl_contentPanel);
        {
            textField = new JTextField();
            GridBagConstraints gbc_textField = new GridBagConstraints();
            gbc_textField.anchor = GridBagConstraints.NORTH;
            gbc_textField.fill = GridBagConstraints.HORIZONTAL;
            gbc_textField.gridwidth = 25;
            gbc_textField.insets = new Insets(0, 0, 10, 5);
            gbc_textField.gridx = 1;
            gbc_textField.gridy = 0;
            contentPanel.add(textField, gbc_textField);
            textField.setColumns(10);
        }
        {
            textField_1 = new JTextField();
            GridBagConstraints gbc_textField_1 = new GridBagConstraints();
            gbc_textField_1.gridwidth = 25;
            gbc_textField_1.insets = new Insets(0, 0, 10, 5);
            gbc_textField_1.anchor = GridBagConstraints.NORTH;
            gbc_textField_1.fill = GridBagConstraints.HORIZONTAL;
            gbc_textField_1.gridx = 1;
            gbc_textField_1.gridy = 1;
            contentPanel.add(textField_1, gbc_textField_1);
            textField_1.setColumns(10);
        }
        {
            table = new JTable();
            GridBagConstraints gbc_table = new GridBagConstraints();
            gbc_table.insets = new Insets(0, 0, 0, 5);
            gbc_table.anchor = GridBagConstraints.NORTH;
            gbc_table.gridwidth = 3;
            gbc_table.gridx = 1;
            gbc_table.gridy = 2;

             DefaultTableModel model = new DefaultTableModel(data, columnNames);
                final JTable table = new JTable(model);/*{
                    @Override
                    public Dimension getPreferredScrollableViewportSize()
                    {
                        return new Dimension(100, 100);
                    }
                };*/
                table.setPreferredScrollableViewportSize(new Dimension(425, 200));
                table.setFillsViewportHeight(true);
                table.getColumnModel().getColumn(0).setPreferredWidth(90);
                table.getColumnModel().getColumn(1).setPreferredWidth(120);
                table.getColumnModel().getColumn(2).setPreferredWidth(120);
                table.getColumnModel().getColumn(3).setPreferredWidth(40);
                JScrollPane jsp = new JScrollPane(table);
                GridBagConstraints jsp_scroll = new GridBagConstraints();
                jsp_scroll.insets = new Insets(0, 0, 0, 5);
                jsp_scroll.fill = GridBagConstraints.BOTH;
                jsp_scroll.gridwidth = 25;
                jsp_scroll.gridx = 1;
                jsp_scroll.gridy = 3;

                contentPanel.add(jsp, jsp_scroll);
        }
        {
            JPanel buttonPane = new JPanel();
            buttonPane.setBackground(Color.WHITE);
            buttonPane.setLayout(new FlowLayout(FlowLayout.RIGHT));
            getContentPane().add(buttonPane, BorderLayout.SOUTH);
            {
                JButton okButton = new JButton("OK");
                okButton.setBackground(Color.WHITE);
                okButton.setActionCommand("OK");
                buttonPane.add(okButton);
                getRootPane().setDefaultButton(okButton);
            }
            {
                JButton cancelButton = new JButton("Cancel");
                cancelButton.setBackground(Color.WHITE);
                cancelButton.setActionCommand("Cancel");
                buttonPane.add(cancelButton);
            }
        }
    }

}

Answer 1

static Vector<Vector<String>> data = new Vector<Vector<String>>();

数据是类级变量。

在您的情况下，您不需要类级别变量来存储数据。

相反，你可以在FindStudent（）构造函数中有一个局部变量。

Answer 2

请你发表以下声明：

{{assignCtrl.carrierForm.$error | json }}

作为构造函数中的第一个语句：

Vector<Vector<String>> data = new Vector<Vector<String>>();并查看结果？

完成上述更改后，您的课程如下所示：

public FindStudent()

Answer 3

在开始迭代结果集之前，要么data是非静态的，要么data.clear()。

重复jtable条目

3 个答案: