为什么我用idea连接mysql会一直报异常，我已经驱动包导进去了

Question

package cn;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import com.mysql.jdbc.Driver;

public class jdbc {
    public static void main(String[] args) throws  Exception {

                Class.forName("com.mysql.jdbc.Driver");
        System.out.println("数据库驱动加载成功");
        Connection conn = DriverManager.getConnection("jdbc:mysql//localhost:3306/girls", "root", "123456");
        System.out.println("创建连接成功");
        String sql="update admin set username= 9999 where id=1";
        Statement stmt = conn.createStatement();
        int count = stmt.executeUpdate(sql);
        System.out.println( count  );
        stmt.close();
        conn.close();
    }

}

Answer 1

url写错了。mysql后面少写了冒号:

package cn;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import com.mysql.jdbc.Driver;
public class jdbc {
    public static void main(String[] args) throws  Exception {
                Class.forName("com.mysql.jdbc.Driver");
        System.out.println("数据库驱动加载成功");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/girls", "root", "123456");
        System.out.println("创建连接成功");
        String sql="update admin set username= 9999 where id=1";
        Statement stmt = conn.createStatement();
        int count = stmt.executeUpdate(sql);
        System.out.println( count  );
        stmt.close();
        conn.close();
    }
}