在一个查询中从多个连接获取java ResultSet

import java.sql.*;

public class MultipleResultSetExample {
    public static void main(String[] args) {
        try {
            // 创建第一个数据库连接
            Connection conn1 = DriverManager.getConnection("jdbc:mysql://localhost:3306/db1", "username1", "password1");
            Statement stmt1 = conn1.createStatement();
            ResultSet rs1 = stmt1.executeQuery("SELECT * FROM table1");

            // 创建第二个数据库连接
            Connection conn2 = DriverManager.getConnection("jdbc:mysql://localhost:3306/db2", "username2", "password2");
            Statement stmt2 = conn2.createStatement();
            ResultSet rs2 = stmt2.executeQuery("SELECT * FROM table2");

            // 创建一个新的ResultSet对象，用于保存合并结果
            ResultSet mergedResultSet = new MergeResultSet(rs1, rs2);

            // 遍历合并结果并进行处理
            while (mergedResultSet.next()) {
                // 处理每一行数据
                // ...
            }

            // 关闭连接和结果集
            rs1.close();
            stmt1.close();
            conn1.close();
            rs2.close();
            stmt2.close();
            conn2.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

// 自定义一个合并ResultSet的类
class MergeResultSet implements ResultSet {
    private ResultSet rs1;
    private ResultSet rs2;

    public MergeResultSet(ResultSet rs1, ResultSet rs2) {
        this.rs1 = rs1;
        this.rs2 = rs2;
    }

    // 实现ResultSet接口的各种方法，将调用对应的rs1或rs2对象的方法
    // ...
}