jdbc 连接mysql数据库_MySQL

jdbc驱动到官网下载，放在jdk的相关目录下面，或者jar文件加入到工程下面

package test_mysql;import java.sql.*;import java.util.Set;public class testjdbc {   public static Connection getConnection() throws ClassNotFoundException, SQLException{       String URL="jdbc:mysql://localhost:3306/employees";     //加载驱动程序        Class.forName("com.mysql.jdbc.Driver");     String user="root";     String passwd="";       //默认密码为空        //还有选择数据库，哪个数据      //DriverManager.        //Connection con=DriverManager.getConnection(URL, user, passwd);        //Connection con=DriverManager.getConnection(url, user, password);      String test_url="";     //String my_url="jdbc:mysql://localhost:3306;DatabaseName=employees;User=root;Password=";       //test_url+=URL+3306+";"+"DatabaseName=employees;"+"User=root;"+"Password="+"";     Connection con=DriverManager.getConnection(URL,user,passwd);        return con; }   public static void main(String[] args){     String sql="select * fromdepartments";      Statement statement=null;       Connection con=null;        ResultSet set=null;     try {           con = getConnection();          //con.set           if(con==null)               System.out.println("con null");         statement=con.createStatement();            set=statement.executeQuery(sql);            //int n=set.getFetchSize();         //System.out.println(n);            while(set.next()){              System.out.println(set.getString(1)+""+set.getString(2));           }       } catch (ClassNotFoundException e) {            // TODO Auto-generated catch block          e.printStackTrace();        } catch (SQLException e) {          // TODO Auto-generated catch block          e.printStackTrace();        }finally{   if(con!=null)       try {           set.close();            statement.close();          con.close();                    } catch (SQLException e) {          // TODO Auto-generated catch block          e.printStackTrace();        }       }           }}