java调取数据库

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

/**
 * Created by liwenj on 2017/8/7.
 */
public class T1 {
    public static void main(String[] args) throws Exception {
        //取得jdbc的驱动包
        Class.forName("com.mysql.jdbc.Driver");
        //取得数据库
        String url="jdbc:mysql://localhost:3306/test";
        String user="root";
        String password="123";
        Connection connection=DriverManager.getConnection(url,user,password);
        Statement statement = connection.createStatement();
        //增加表格
        String sql="INSERT INTO user1(NO,NAME,age,sex) VALUES('001','小明',22,'男')";
        int i=statement.executeUpdate(sql);
        System.out.println(i);
        //更改表格
        String upsql="UPDATE user1 SET sex='女',age=21  WHERE NO='003'";
        statement.executeUpdate(upsql);
        //删除表格
        String delsql="DELETE FROM user1 WHERE NO='001'";
        statement.executeUpdate(delsql);
        ResultSet resultSet = statement.executeQuery("SELECT * FROM user1 WHERE NO='002'AND NAME='李四'");
        while (resultSet.next()){
            String no = resultSet.getString("no");
            int age = resultSet.getInt("age");
            String sex = resultSet.getString("sex");
            System.out.println(no+"---"+age+"---"+sex);
        }
        resultSet.close();
        statement.close();
        connection.close();
    }
}
异常报错版本

import java.sql.*;

/**
 * Created by liwenj on 2017/8/7.
 */
public class T1 {
    public static void main(String[] args) {
        Connection connection=null;
        Statement statement=null;
        ResultSet resultSet=null;
        try{
            //取得jdbc的驱动包
            Class.forName("com.mysql.jdbc.Driver");
            //取得数据库
            String url="jdbc:mysql://localhost:3306/test";
            String user="root";
            String password="123";
            connection=DriverManager.getConnection(url,user,password);
            statement = connection.createStatement();
            //增加表格
            String sql="INSERT INTO user1(NO,NAME,age,sex) VALUES('001','小明',22,'男')";
            int i=statement.executeUpdate(sql);
            System.out.println(i);
            //更改表格
            String upsql="UPDATE user1 SET sex='女',age=21  WHERE NO='003'";
            statement.executeUpdate(upsql);
            //删除表格
            String delsql="DELETE FROM user1 WHERE NO='001'";
            statement.executeUpdate(delsql);
            resultSet = statement.executeQuery("SELECT * FROM user1 WHERE NO='002'AND NAME='李四'");
            while (resultSet.next()){
                String no = resultSet.getString("no");
                int age = resultSet.getInt("age");
                String sex = resultSet.getString("sex");
                System.out.println(no+"---"+age+"---"+sex);
            }
        }catch (Exception e){
            System.out.println("出错");
            e.fillInStackTrace();
        }finally {
            if (resultSet!=null){
                try {
                    resultSet.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if(statement!=null){
                try {
                    statement.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if(connection!=null){
                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

        }
    }
}