Hashtable映射数据库字段

 package com.test;
 
 import java.sql.*;
 import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.List;
 public class Test{
     // 驱动
     String driver = "com.mysql.jdbc.Driver";
     // 数据库连接
     String url = "jdbc:mysql://localhost:3306/ceshi?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&transformedBitIsBoolean=true";
     // 用户名
     String user = "root";
     // 数据库密码
     String password = "hotlon";
     // 加载驱动
 
     List<Hashtable<String, Object>> rows ;
 
     public List<Hashtable<String, Object>> queSql(){
 
         try {
             Class.forName(driver);
         } catch (ClassNotFoundException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         // 获取链接
         Connection connection = null;
         try {
             connection = DriverManager.getConnection(url, user, password);
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         // 创建查询声明
         PreparedStatement preparedStatement = null;
         try {
             preparedStatement = connection.prepareStatement("select * from renyuan");
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         // 获取结果
         ResultSet resultSet = null;
         try {
             resultSet = preparedStatement.executeQuery();
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         // 获取各个列的信息
         ResultSetMetaData metaData = null;
         try {
             metaData = resultSet.getMetaData();
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         // 一条数据保存在一个Hashtable 将所有Hashtable存放到list
         rows = new ArrayList<Hashtable<String, Object>>();
         try {
             while (resultSet.next()) {
                 Hashtable<String, Object> row = new Hashtable<String, Object>();
                 for (int i = 1; i <= metaData.getColumnCount(); i++) {
                     // 打印列名
                     //System.out.println(metaData.getColumnName(i));
                     //System.out.println(row.get(metaData.getColumnName(i)));
                     row.put(metaData.getColumnName(i), resultSet.getObject(i)==null?"":resultSet.getObject(i));
                     //System.out.println(row.get(metaData.getColumnName(i)));
                     }
                 rows.add(row);
                 }
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         try {
             resultSet.close();
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         try {
             preparedStatement.close();
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         try {
             connection.close();
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
 
         //System.out.println(rows.get(1).get("uid"));
         return rows;
 
     }
 
     public static void main(String[] args) throws Exception {
 
         Test test = new Test();
         System.out.println(test.queSql().get(1).get("uid"));
 
         }
     }