jdbc获取mysql自动生成的主键

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

import cn.itcast.utils.JdbcUtils;

public class Demo4 {

    /**
     * 获取自动生成的主键
     create table test1
     (
         id int primary key auto_increment,
         name varchar(20)
     );
     */
    public static void main(String[] args) {
        
        Connection conn = null;
        PreparedStatement st = null;
        ResultSet rs = null;
        
        try{
            conn = JdbcUtils.getConnection();
            String sql = "insert into test1(name) values(?)";
            st = conn.prepareStatement(sql);
            st.setString(1, "aaa");
            st.executeUpdate();
            
            rs = st.getGeneratedKeys();
            if(rs.next()){
                System.out.println(rs.getInt(1));
            }
        }catch (Exception e) {
            e.printStackTrace();
        }finally{
            JdbcUtils.release(conn, st, rs);
        }

    }

}