java mysql ubuntu problem

[maxxx12345]

Hello!

Thanks for letting participate.

I've got the following problem:

Installed: Ubuntu 10.04, Java 7 and a MySQL Server

I now want to connect to the Server with Java but get the following error from the following code.

I've tried to fix it by browsing google but it didn't help.

I already say thank you for helping me.

Max

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/test
java.lang.NullPointerException
java.lang.NullPointerException

import java.sql.*;
import javax.sql.*;
import java.io.*;
import java.util.*;

/**This Class queries the specified databases with the specified parameters and returns all
relevant information*/
public class DBQuery{

    private String dburl;
    private String user;
    private String password;
    private String query;
    private ArrayList<ArrayList<Object>> publicdata = new ArrayList<ArrayList<Object>>();
    private int actualcolumn = 1;
    private int actualrow = 1;
    private Connection cn;

    /**Database Query for MYSQL Databases*/
    DBQuery(String host, String database, String user, String password, String query){

        this.cn = null;
        String dburl = "jdbc:mysql://"+host+"/"+database;
        this.dburl = dburl;
        this.user = user;
        this.password = password;
        this.query = query;

        getData();

    }

    /**Return the data of a database table in an ArrayList*/
    void getData(){

        ArrayList<ArrayList<Object>> data = new ArrayList<ArrayList<Object>>();
        data.clear();
        this.publicdata.clear();
        ResultSet rs = dataFromDB();

        try{
            rs.last(); 
            int rows = rs.getRow(); 
            rs.beforeFirst();
            ResultSetMetaData rsmd = rs.getMetaData();

            ArrayList<Object> names = new ArrayList<Object>();

            for(int i = 0; i < rsmd.getColumnCount(); i++){

                names.add(rsmd.getColumnName(i+1));

            }

            data.add(names);

            for(int i = 1; i <= rsmd.getColumnCount(); i++){
                ArrayList<Object> a = new ArrayList<Object>();
                rs.beforeFirst();
                for(int e = 1; e <= rows; e++){

                    rs.next();
                    a.add(rs.getString(i));
                    if(e==rows){

                        data.add(a);

                    }
                }

            }

        }
        catch(Exception e){
            System.out.println(e);
        }

        this.publicdata = data;

        try{
            cn.close();
        }
        catch(Exception e){
            System.out.println(e);
        }

    }

    /**Returns the Value on the specified position of the result of this Query*/
    public Object getValue(int column, int row){

        this.actualcolumn = column;
        this.actualrow = row;

        return publicdata.get(column-1+1).get(row-1);

    }

    /**Returns the total Number of Columns of the result of this Query*/
    public int getTotalNumberOfColumns(){

        return publicdata.get(0).size();

    }

    /**Returns the total Number of Rows of the result of this Query*/
    public int getTotalNumberOfRows(){

        return publicdata.get(1).size();

    }

    /**Acts like a cursor, which shows the postion of the column, the has been asked for the latest*/
    public int getActualColumn(){

        return actualcolumn;

    }

    /**Acts like a cursor, which shows the postion of the row, the has been asked for the latest*/
    public int getActualRow(){

        return actualrow;

    }
    /**Sets the cursor of the Row*/
    public void setRow(int x){

        if(x > 1){
            this.actualrow=x;
        }

    }
    /**Sets the cursor of the Column*/
    public void setColumn(int x){
        if(x>1){
            this.actualcolumn=x;

        }
    }

    /**Return the name of the specific column 'x'*/
    public String getNameofColumn(int x){

        return (String) publicdata.get(0).get(x-1);

    }

    void printOut(){

        ArrayList<ArrayList<Object>> datb = publicdata;

        ArrayList<Object> columnnames = new ArrayList<Object>();

        columnnames.add(datb.get(0));
        datb.remove(0);

        System.out.print(columnnames.get(0));
        System.out.println();
        for(int i = 0; i < datb.size(); i++){
            for(int e = 0; e < datb.get(i).size(); e++){

                System.out.print(datb.get(i).get(e)+ " | ");

            }
            System.out.println();
        }

    }

    /**Executes the Database Query*/
    ResultSet dataFromDB(){

        Statement  st = null;
        ResultSet  rs = null;
        try{
            cn = DriverManager.getConnection(dburl, user, password);
            st = cn.createStatement();
            rs = st.executeQuery(query);
        }
        catch(Exception e){
            System.out.println(e);
        }

        return rs;

    }
}

[StormyWaters]

Do you have the mysql-connector jar in your classpath? Usually before establishing the database connection, I would expect to see the following:

Class.forName("com.mysql.jdbc.Driver");

[DarrylBurke]

Moved from New to Java

db

[Tolls]

Do you have the mysql-connector jar in your classpath? Usually before establishing the database connection, I would expect to see the following:

Class.forName("com.mysql.jdbc.Driver");

That's not been necessary for a while now.
The Driver gets registered automatically.

[maxxx12345]

I've added this line in the dataFromDB Method now, but it still doesnt work

[Tolls]

That line is not the solution.

The first part of StormyWaters reply is.
You don't have the driver jar file in your classpath.