import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import java.util.List;public class TestResultSet {  public static List query(){    Connection conn = new ConnectionUtil().openConnection();    try {      Statement stmt = conn.createStatement();      String sql = "select id,name,email from customertbl";      ResultSet rs = stmt.executeQuery(sql);      //將結果集封裝到List中      List list = new ArrayList();      while(rs.next()){        // 可以根據列名稱也可以根據列索引        int id = rs.getInt(1);        String name = rs.getString("name");        String email = rs.getString("email");        System.out.println(id+":"+name+":"+email);        Customer c = new Customer();        c.setId(id);        c.setName(name);        c.setEmail(email);        //將對象存放到list容器中        list.add(c);      }      return list;    } catch (SQLException e) {      // TODO Auto-generated catch block      e.printStackTrace();    }finally{      try {        conn.close();      } catch (SQLException e) {        conn = null;        e.printStackTrace();      }    }    return null;  }}