O código a seguir:

Class.forName("com.mysql.jdbc.Driver");
Connection m_connection = DriverManager.getConnection("jdbc:mysql://localhost","root","root");

Lança esta exceção nogetConnection():

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:919)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1694)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1244)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2397)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2430)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at db.Database.<init>(Database.java:91)
    at db.Main.main(Main.java:10)

Como isso é causado e como posso resolvê-lo?

EDITAR:

    public static void main(String[] args) throws ClassNotFoundException, ServletException, SQLException 
    {

        try
        {
            Connection conn = (Connection) DriverManager.getConnection("jdbc:mysql://localhost/?user=root&password=rootpassword"); 
            Statement   s = (Statement) conn.createStatement();
            int result = s.executeUpdate("CREATE DATABASE databasename");
        }


        catch ( Exception e)
        {
            e.printStackTrace();
        }
}

Produz:

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4074)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4006)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:919)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1694)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1244)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2397)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2430)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at db.Main.main(Main.java:19)