Establishing connection to MySQL server/database

Question

Hi! I've got a question about subj. Here is my code:
import java.sql.*;
import java.util.*;
class SQLDB {
    int db_port;
    String db_url, db_name, db_table, db_user, db_passwd;
    public void dbConnect() throws SQLException {
        Connection con = new Connection();
        Properties prop = new Properties();
        prop.put("charSet", "utf8");
        prop.put("user", db_user);
        prop.put("password", db_passwd);
        con = DriverManager.getConnection(db_url, prop);
}NetBeans says that Connection (Connection con = new Connection()) object is abstract and can't be instantiated. Can anyone suggest me what to do?

Answer 1

Agree :) But faced another problem. I made this part of code after reading various info on this matter:
package dbCinema;
import java.sql.*;
//import java.util.*;
class SQLDB {
    private int db_port;
    private String db_url, db_name, db_user, db_passwd;
    private Connection con = null;
    private Statement db_query = null;
    private ResultSet rs = null;
    SQLDB(String dburl, String dbname, String dbuser, String dbpasswd, int dbport) {
        db_url = dburl;
        db_name = dbname;
        db_user = dbuser;
        db_passwd = dbpasswd;
        db_port = dbport;
    public void dbConnect() {
        String url;
        //url = "jdbc:mysql://" + db_url + ":" + db_port + "/" + db_name;
        url = "jdbc:mysql://" + db_url + "/" + db_name;
        try {
            Class.forName("org.gjt.mm.mysql.Driver");
            con = DriverManager.getConnection(url, db_user, db_passwd);
            if (!con.isClosed())
                System.out.println(db_name + ": connection established.");
        } catch (SQLException e) {
            System.err.println("Exception: " + e.getMessage());
        } catch (ClassNotFoundException e) {
            System.err.println("Exception: " + e.getMessage());
    public void dbQuery(String query) throws SQLException {
        db_query = con.createStatement();
        rs = db_query.executeQuery(query);
        while (rs.next()){
            System.out.println(rs.getString(3));
    public static void main(String args[])  {
        SQLDB comm = new SQLDB("localhost", "cinema", "", "", 3306);
        try {
            comm.dbConnect();
            comm.dbQuery("SELECT * from t_movies WHERE id=1");
        } catch (SQLException e) {
            System.err.println("Exception: " + e.getMessage());
}And having this error as a result of running this class:
> "java" SQLDB
java.lang.NoClassDefFoundError: SQLDB (wrong name: dbCinema/SQLDB)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at java.net.URLClassLoader.defineClass(Unknown Source)
     at java.net.URLClassLoader.access$000(Unknown Source)
     at java.net.URLClassLoader$1.run(Unknown Source)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.net.URLClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Exception in thread "main"
Process Exit Code: 1
Time Taken: 00:01I've downloaded and installed into my java jre/lib/ext folder this driver (mysql-connector-java-5.1.6-bin.jar) to make connection possible. What's wrong?
Edited by: Utah on Aug 14, 2008 12:12 PM