MyEclipse连接 mysql 出错? 400 报错

MyEclipse连接 mysql 出错? 400 报错

import java.sql.Connection;
import java.sql.Statement;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import javax.swing.JFrame;
import com.sun.org.apache.xerces.internal.impl.dv.DVFactoryException;

class Lianjie{
    public static final String DBurl = "jdbc:mysql//localhost:3306/mldn";
    public static final String Dri = "org.gjt.mm.mysql.Driver";
    public static final String User = "root";
    public static final String Password = "root";
    public Lianjie() throws  SQLException{

  
 
   try {
    Class.forName(Dri);
   } catch (ClassNotFoundException e) {
    System.out.println("出现错误"+e);
   } 

       Connection conn=null;
       Statement state=null;
       conn= DriverManager.getConnection(DBurl, User, Password);
       state=conn.createStatement();
      
       String sql="insert into user(id,name)values(3,3)";
       state.executeUpdate(sql);
       conn.close();
    }
}
public class Connectdemo1 {
   public static void main(String[] args) throws ClassNotFoundException, SQLException {
                 new Lianjie();
    
 }
 }

运行以上代码编译器得到以下提示：

Exception in thread "main" java.sql.SQLException: No suitable driver
 at java.sql.DriverManager.getConnection(Unknown Source)
 at java.sql.DriverManager.getConnection(Unknown Source)
 at Shizhanjindian_17.Lianjie.<init>(Connectdemo1.java:27)
 at Shizhanjindian_17.Connectdemo1.main(Connectdemo1.java:37)

第一个提示没有合适的驱动。

去掉以下代码

       Connection conn=null;
       Statement state=null;
       conn= DriverManager.getConnection(DBurl, User, Password);
       state=conn.createStatement();
      
       String sql="insert into user(id,name)values(3,3)";
       state.executeUpdate(sql);
       conn.close();

经测试 编译器得到结果没有任何错误  驱动加载通过。

提示 驱动 报错 求解。。。

并且

at Shizhanjindian_17.Lianjie.<init>(Connectdemo1.java:27)---->

conn= DriverManager.getConnection(DBurl, User, Password);

at Shizhanjindian_17.Connectdemo1.main(Connectdemo1.java:37)----->

            new Lianjie();

看不懂存在的问题。麻烦各位大哥帮忙解释一下。十分感谢