ResultSet:结果集。存放数据库中的数据，可以将它想象成一张数据表，通过Statement对象中的executeQuery()方法获得

import com.mysql.jdbc.Statement;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.ResultSet;
import java.util.Properties;

/**
 * Created by I am master on 2016/9/29.
 */
public class finallyjdbc {
    public static void main(String[] args) throws Exception{
            Connection connection=null;
            Statement  statement=null;


                Driver driver = new com.mysql.jdbc.Driver();
                String url = "jdbc:mysql://localhost:3306/student";
                Properties properties = new Properties();
                properties.put("user", "root");
                properties.put("password", "root");
                connection = driver.connect(url, properties);
                statement = (Statement) connection.createStatement();
                /*执行查询一条语句的操作*/
                String query1 = "select * from studentInfo where id=1";
                ResultSet resultSet1=statement.executeQuery(query1);
                if(resultSet1.next()){
                    int id=resultSet1.getInt(1);
                    String name=resultSet1.getString("name");
                    int age=resultSet1.getInt(3);
                    String major=resultSet1.getString("class");
                    System.out.print(id);
                    System.out.print(name);
                    System.out.print(age);
                    System.out.println(major);

                }
                /*执行查询多条语句的操作*/
                String query2 = "select * from studentInfo";
                ResultSet resultSet2=statement.executeQuery(query2);
                while (resultSet2.next()){
                    String id=resultSet2.getString("id");
                    String name=resultSet2.getString("name");
                    String age=resultSet2.getString("age");
                    String major=resultSet2.getString("class");
                    System.out.print(id);
                    System.out.print(name);
                    System.out.print(age);
                    System.out.println(major);

                }

        if(resultSet2!=null)
                resultSet2.close();
        if(resultSet1!=null)
                resultSet1.close();
        if(statement!=null)
                statement.close();
        if(connection!=null)
                connection.close();





                }

            }

JDBC中的ResultSet