Java fails to connect mysql

Question

HELP!! What have i done wrong here?
Ive downloaded a mysql driver and the adress is c:\mm.mysql.jdbc-1.2c
iv'e set a classpath in autoexec.bat CLASSPATH=C:\mm.mysql.jdbc-1.2c\;%CLASSPATH%
And my connection source is
import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class CreateCoffees {
public static final String dbdriver = "org.gjt.mm.mysql.Driver";
private static Connection con;
public static void main(String args[]) { 
     try{
          String url = "jdbc:mysql:/shop";
con= DriverManager.getConnection(url + "?user=xxx&password=xxx"); ;
     } catch (SQLException ex) {
// handle any errors
System.out.println("SQLException: " + ex.getMessage());
System.out.println("SQLState: " + ex.getSQLState());
System.out.println("VendorError: " + ex.getErrorCode());
     String sqlinsert;
     sqlinsert = "create table Person " +
     "(Namn varchar(32), " +
     "Pnr int, " +
     "Lon int, " +
     "Vikt int)";
     Statement stmt;
     try {
     Class.forName("dbdriver");
     } catch(java.lang.ClassNotFoundException e) {
     System.err.print("ClassNotFoundException: ");
     System.err.println(e.getMessage());
     try {
     stmt = con.createStatement();
     stmt.executeUpdate(sqlinsert);
     stmt.close();
     con.close();
     } catch(SQLException ex) {
     System.err.println("SQLException: " + ex.getMessage());
}

Answer 1

HELP!! What have i done wrong here?What, specifically, is the error message you are receiving?
Ive downloaded a mysql driver and the adress is
c:\mm.mysql.jdbc-1.2c
iv'e set a classpath in autoexec.bat
CLASSPATH=C:\mm.mysql.jdbc-1.2c\;%CLASSPATH%I'm assuming you have the .class files for the JDBC driver under C:\mm.mysql.jdbc-1.2c. Obviously, if .class files for the driver are in a .jar file in that directory, you'll need to add the .jar file to the CLASSPATH.
And my connection source is
import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class CreateCoffees {
public static final String dbdriver =
= "org.gjt.mm.mysql.Driver";
private static Connection con;
public static void main(String args[]) { 
     try{
          String url = "jdbc:mysql:/shop";
con= DriverManager.getConnection(url +
l + "?user=xxx&password=xxx"); ;
     } catch (SQLException ex) {
// handle any errors
System.out.println("SQLException: " +
eption: " + ex.getMessage());
System.out.println("SQLState: " +
LState: " + ex.getSQLState());
System.out.println("VendorError: " +
rError: " + ex.getErrorCode());
     String sqlinsert;
     sqlinsert = "create table Person " +
     "(Namn varchar(32), " +
     "Pnr int, " +
     "Lon int, " +
     "Vikt int)";
     Statement stmt;***********************************************           
     try {
     Class.forName("dbdriver");
     } catch(java.lang.ClassNotFoundException e) {
     System.err.print("ClassNotFoundException: ");
     System.err.println(e.getMessage());
I believe (someone correct me if I'm wrong), that this block of code has to be done before you do the code that you have above this block. The Class.forName call makes the DriverManager aware of the class to use as a driver to the database. The DriverManager can't make the connection to the database, because it doesn't know the driver class.
Also, you have defined a variable dbdriver, BUT, when you are calling Class.forName, you're not using that variable. Why? Because you have "dbdriver", not dbdriver.
     try {
     stmt = con.createStatement();
     stmt.executeUpdate(sqlinsert);
     stmt.close();
     con.close();
     } catch(SQLException ex) {
System.err.println("SQLException: " +
" + ex.getMessage());
}I would assume your code should look something like this (this might not be 100% right, but it's probably fairly close):
import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class CreateCoffees
   public static final String dbdriver = "org.gjt.mm.mysql.Driver";
   public static void main(String args[])
      Connection con=null;
      Statement stmt=null;
      try
         Class.forName(CreateCoffees.dbdriver);
         String url = "jdbc:mysql:/shop";           
         con= DriverManager.getConnection(url + "?user=xxx&password=xxx");  ;
         String sqlinsert = "create table Person " +
            "(Namn varchar(32), " +
            "Pnr int, " +
            "Lon int, " +
            "Vikt int)";
         Statement stmt = con.createStatement();
         stmt.executeUpdate(sqlinsert);
      catch(java.lang.ClassNotFoundException e)
      {  System.err.print("ClassNotFoundException: ");
         System.err.println(e.getMessage());
      catch (SQLException ex)
         // handle any errors
         System.out.println("SQLException: " + ex.toString());
         System.out.println("SQLState: " + ex.getSQLState());
         System.out.println("VendorError: " + ex.getErrorCode());
      finally
         try
         {  stmt.close();
            conn.close();
         catch(SQLException ex)
            System.out.println("SQLException: " + ex.toString());
            System.out.println("SQLState: " + ex.getSQLState());
            System.out.println("VendorError: " + ex.getErrorCode());
      }  // finally          
   }  // main
}Hope that helps.
Kevin