用Java实现多线程环境下的数据库访问

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DatabaseAccess {
    private static final String DB_URL = "jdbc:mysql://localhost:3306/mydatabase";
    private static final String DB_USER = "username";
    private static final String DB_PASSWORD = "password";

    public static void main(String[] args) {
        // 创建多个线程来同时访问数据库
        for (int i = 0; i < 10; i++) {
            Thread thread = new Thread(new DatabaseThread());
            thread.start();
        }
    }

    static class DatabaseThread implements Runnable {
        @Override
        public void run() {
            Connection connection = null;
            PreparedStatement statement = null;
            ResultSet resultSet = null;

            try {
                // 建立数据库连接
                connection = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);

                // 创建查询语句
                String sql = "SELECT * FROM users";
                statement = connection.prepareStatement(sql);

                // 执行查询
                resultSet = statement.executeQuery();

                // 处理查询结果
                while (resultSet.next()) {
                    String username = resultSet.getString("username");
                    System.out.println("Username: " + username);
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                // 关闭数据库连接
                try {
                    if (resultSet != null) {
                        resultSet.close();
                    }
                    if (statement != null) {
                        statement.close();
                    }
                    if (connection != null) {
                        connection.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}