使用jdbc将结果作为变量查询在另一个数据库中

import java.sql.*;

public class JDBCTest {
    public static void main(String[] args) {
        Connection conn1 = null;
        Connection conn2 = null;
        Statement stmt1 = null;
        Statement stmt2 = null;
        ResultSet rs1 = null;
        ResultSet rs2 = null;

        try {
            // 第一个数据库连接
            conn1 = DriverManager.getConnection("jdbc:mysql://localhost:3306/db1", "username", "password");
            stmt1 = conn1.createStatement();
            String query1 = "SELECT column1 FROM table1 WHERE condition";
            rs1 = stmt1.executeQuery(query1);

            // 获取结果并保存到变量中
            String variable = null;
            if (rs1.next()) {
                variable = rs1.getString("column1");
            }

            // 第二个数据库连接
            conn2 = DriverManager.getConnection("jdbc:mysql://localhost:3306/db2", "username", "password");
            stmt2 = conn2.createStatement();
            String query2 = "SELECT * FROM table2 WHERE column2 = '" + variable + "'";
            rs2 = stmt2.executeQuery(query2);

            // 处理第二个数据库返回的结果
            while (rs2.next()) {
                // 打印结果或进行其他操作
                System.out.println(rs2.getString("column3"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接和资源
            try {
                if (rs1 != null) rs1.close();
                if (stmt1 != null) stmt1.close();
                if (conn1 != null) conn1.close();
                if (rs2 != null) rs2.close();
                if (stmt2 != null) stmt2.close();
                if (conn2 != null) conn2.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}