Java Database Connectivity (JDBC)

Hi, guys

I am newbie in here, I just seek help for my jdbc connection, my error like this

Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2103)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
at DaoMySQL.<init>(DaoMySQL.java:36)
at DaoMySQL.main(DaoMySQL.java:130)
Caused by: java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:518)
at java.net.Socket.connect(Socket.java:468)
at java.net.Socket.<init>(Socket.java:365)
at java.net.Socket.<init>(Socket.java:208)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:280)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2026)
... 13 more


my testing code like this, sorry I forget where the link.

public class DaoMySQL {

private Connection connect = null;

private Statement statement = null;

private ResultSet resultSet = null;



public DaoMySQL() throws Exception {

try {



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

connect = DriverManager

.getConnection("jdbc:mysql://localhost/feedback?"

+ "user=administrator&password=sd2003nt");

PreparedStatement statement = connect

.prepareStatement("SELECT myuser, webpage, datum, summery, COMMENTS from FEEDBACK.COMMENTS");



resultSet = statement.executeQuery();

while (resultSet.next()) {

String user = resultSet.getString("myuser");

String website = resultSet.getString("webpage");

String summery = resultSet.getString("summery");

Date date = resultSet.getDate("datum");

String comment = resultSet.getString("comments");

System.out.println("User: " + user);

System.out.println("Website: " + website);

System.out.println("Summery: " + summery);

System.out.println("Date: " + date);

System.out.println("Comment: " + comment);

}

} catch (Exception e) {

throw e;

} finally {

close();

}



}





private void close() {

try {

if (resultSet != null) {

resultSet.close();

}



if (statement != null) {

statement.close();

}



if (connect != null) {

connect.close();

}

} catch (Exception e) {



}

}



public static void main(String[] args) throws Exception {

DaoMySQL dao = new DaoMySQL();

}



}


I use mandriva 2008..0, java sun1.6.0 ( Install from rpm-so I think, I dont have to set the classpath), I put mysql-java connector5.1 in /jdk/jre/lib/ext ( so, do not need set classpath-I think), my database mysql 5.0

I also install odbc driver and my database can be remote, could be 2 connector is conflict?

My problem, I can't read where I am wrong either in source code or in my setting mysql-java connector. Am I put the connector java too high than database or what?

Please guys, show me where I am wrong , thanks your support.