java连接mysql数据库

import java.sql.*;
public class TestMySQL {
public TestMySQL() {
}
public static void main(String[] args) {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql","root","root");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from student");
while(rs.next()){
 System.out.println(rs.getString(2));
}
stmt.close();
conn.close();
}
catch (SQLException ex) {
ex.printStackTrace();
}catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
}

} 

解释一下下面这句话

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql","root","root");

mysql--数据库名

两个root，前面一个是用户名，后面一个是密码