mysql jdbc操作

import java.sql.*;
import java.util.Map;

public class Mysql {
    public static void main(String[] args) {
        Connection conn = getConn();
        PreparedStatement pstmt;
        try {
            pstmt = conn.prepareStatement("select * from lw_area where area_id like '35%' and area_level <=3");
            ResultSet rs = pstmt.executeQuery();
            //Map<String, Map<String, Object>>  
            while (rs.next()) {
                System.out.println(rs.getLong("area_id"));
                System.out.print(rs.getLong("area_pid"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    private static Connection getConn() {
        String driver = "com.mysql.cj.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/linewell_assets_mgt_es?serverTimezone=UTC";
        String username = "root";
        String password = "123456";
        Connection conn = null;
        try {
            Class.forName(driver); //classLoader,加载对应驱动
            conn = DriverManager.getConnection(url, username, password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

把结果转化成map形式：

ResultSet rs = stmt.executeQuery(sql);
ResultSetMetaData md = rs.getMetaData();
int columnCount = md.getColumnCount();
while (rs.next()) {
    Map<String, Object> rowData = new HashMap<String, Object>();
    for (int i = 1; i <= columnCount; i++) {
        rowData.put(md.getColumnName(i), rs.getObject(i));
    }
}