用JFrame实现查询表中的内容并用JTable输出

好的，我可以为您提供一个简单的示例代码，用JFrame实现查询表中的内容并用JTable输出。以下是代码：

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;

public class QueryTable extends JFrame {

private JLabel label;
private JTextField textField;
private JButton button;
private JTable table;
private DefaultTableModel tableModel;

public QueryTable() {
    setTitle("查询表中的内容");
    setSize(500, 400);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());

    label = new JLabel("请输入要查询的表名：");
    textField = new JTextField(20);
    button = new JButton("查询");
    tableModel = new DefaultTableModel();
    table = new JTable(tableModel);
    JScrollPane scrollPane = new JScrollPane(table);

    JPanel topPanel = new JPanel();
    topPanel.add(label);
    topPanel.add(textField);
    topPanel.add(button);

    button.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            String tableName = textField.getText();
            if (tableName != null && !tableName.equals("")) {
                try {
                    // 连接数据库
                    Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");
                    Statement stmt = conn.createStatement();

                    // 查询表中的所有内容
                    String sql = "SELECT * FROM " + tableName;
                    ResultSet rs = stmt.executeQuery(sql);

                    // 获取表的列数
                    ResultSetMetaData metaData = rs.getMetaData();
                    int columnCount = metaData.getColumnCount();

                    // 将查询结果放入表格中
                    tableModel.setColumnCount(0);
                    tableModel.setRowCount(0);
                    for (int i = 1; i <= columnCount; i++) {
                        tableModel.addColumn(metaData.getColumnLabel(i));
                    }
                    while (rs.next()) {
                        Object[] rowData = new Object[columnCount];
                        for (int i = 1; i <= columnCount; i++) {
                            rowData[i - 1] = rs.getObject(i);
                        }
                        tableModel.addRow(rowData);
                    }

                    // 关闭连接
                    rs.close();
                    stmt.close();
                    conn.close();
                } catch (SQLException ex) {
                    ex.printStackTrace();
                }
            }
        }
    });

    add(topPanel, BorderLayout.NORTH);
    add(scrollPane, BorderLayout.CENTER);

    setVisible(true);
}

public static void main(String[] args) {
    new QueryTable();
}

}

这个程序会打开一个JFrame窗口，上面有一个文本框和一个查询按钮，用户输入要查询的表名后，点击查询按钮，程序会连接数据库并查询指定表中的所有内容，将查询结果放入表格中并输出。