java链接数据库

package com.runoob.test;

import java.sql.*;
public class MysqlDemo {
    //JDBC驱动名与数据库url
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost:3306/runoob";
    
    //数据库与密码
    static final String USER = "root";
    static final String PASS = "123456";
    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        try {
            //注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            
            //打开链接
            System.out.println("链接数据库中。。。");
            conn = DriverManager.getConnection(DB_URL,USER,PASS);
            
            //执行查询
            System.out.println("实例化Statement对象。。。。");
            stmt = conn.createStatement();
            String sql;
            sql = "select id,name,url from websites";
            ResultSet rs = stmt.executeQuery(sql);
            
            //展开结果集数据库
            while(rs.next()) {
                //通过字段检索
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String url = rs.getString("url");
                
                //输出数据
                System.out.print("ID: "+id);
                System.out.print(", name: "+name);
                System.out.print(", url: "+url);
                System.out.println();
            }
            //完成后关闭
            rs.close();
            stmt.close();
            conn.close();
            
        }catch(SQLException es) {
            //处理JDBC错误
            es.printStackTrace();
        }catch(Exception e) {
            //处理Class.forName错误
            e.printStackTrace();
        }finally{
            //关闭资源
            
            try {
                if(stmt!=null) {
                    stmt.close();
                }
            }catch(SQLException es) {
                es.printStackTrace();
            }
        }
        System.out.println("GOOD BYE!");
        
    }
    
}