Access denied for user 'root'@'localhost'

[Norgy]

import java.sql.*;
 
public class DBConnect {
 
    private Connection con;
    private Statement st;
    private ResultSet rs;
 
    public DBConnect(){
        try{
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/DataBaseName","user_name","password");
            st = con.createStatement();
 
        }catch(Exception ex){
            System.out.println("Error: "+ex);
        }
 
    }
 
    public void getData(){
        try{
            String query = "select * from  test";
            rs = st.executeQuery(query);
            System.out.println("Records from Database");
            while(rs.next()){
                String name = rs.getString("name");
                String age = rs.getString("age");
                System.out.println("name: "+name+"  "+"age: "+age);
            }
        }catch(Exception ex){
            System.out.println(ex);
        }
    } 
 
}
 

i have watched a video demonstrating how to connect java netBeans to MySQL server
this code is written in the video, but when i run it, it gives me the error:
Error: java.sql.SQLException: Access denied for user 'user_name'@'localhost' (using password: YES)
java.lang.NullPointerException
what is the problem here ?

[zmbd]

It means that you used the wrong user_name/password combination to attempt a connection to the database.

Contact your DBA to determine the correct username and password.

[Norgy]

but i log in to the server with the same user_name and password

[zmbd]

You're trying to tell me that ","user_name","password"); is your user name and password? I just figured that these were being used as place holders in the code instead of the real information (^_^)

Doesn't matter, because the error is quite clear, the account name and password you have actually used in the code is not correct for the type of connection you are attempting establish, there is no point in arguing this fact.

Contact your DBA to determine the correct username and password.

[zmbd]

Sorry, something just occured to me, it's been a very long time since IT setup my test MYSQL database:

Verify that your MYSQL has a passphrase go to the directory where you installed mysql, and in the bin directory try to bring up mysql prompt using:

./mysql –u root mysql 

If the login goes through without any problem, it means no passphrase is set.
You can use mysqadmin script to set/reset passphrase.

./mysqladmin –u root passphrase "new passphrase"

[Norgy]

no ^_^ i mean that i sign in to the server with the same user name and password written in the code (which are not written here, i wrote only alternative names for them)
anyway, i made a new account with new password and edited the code with the new ones but nothing changed :(
and sometimes it gives me this error
Error: com.mysql.jdbc.exceptions.jdbc4.CommunicationsExce ption: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. java.lang.NullPointerException

[Norgy]

sorry, i have just noticed your last comment
actually, i don't understand what you mean by bringing up mysql prompt.

[iAirplane]

@Norgy
I have the same problem at the moment, I'm sure my password and username is correct but I get the same error, while with a different database on the same server I can connect with the same user.

Since this is a year old, have you solved the problem, and can you help me?