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Communications link failure
Posted by: david bennett
Date: January 16, 2008 01:14AM

Hey,

This is my first time using the jdbc:mysql driver but ive used both Java and mySQL for years.

The mysql server works fine from a CLI or PHP.

Im having an issue connecting to mysql via this driver via both a Java class i made and SQuirreL SQL.

The message i get back from both is:
-----------------------------------------------
-----------------------------------------------

Communications link failure

Last packet sent to the server was 0 ms ago.

-----------------------------------------------
-----------------------------------------------

The full Exception/Stacktrace from java is:
-----------------------------------------------
---------- START JAVA EXCEPTION -------
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SQLException: Communications link failure

Last packet sent to the server was 0 ms ago.
SQLState: 08S01
VendorError: 0

***** START STACK ******

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:2104)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:729)
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:283)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at org.red5.server.webapp.TodayTonight.mysql.Connect(mysql.java:23)
at org.red5.server.webapp.TodayTonight.mysql.main(mysql.java:85)
Caused by: java.net.ConnectException: Connection refused: connect
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:519)
at java.net.Socket.connect(Socket.java:469)
at java.net.Socket.<init>(Socket.java:366)
at java.net.Socket.<init>(Socket.java:209)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:276)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2027)

... 13 more

***** END STACK ******

-----------------------------------------------
----------- END JAVA EXCEPTION --------
-----------------------------------------------

My java src is:

-----------------------------------------------
-------------- START JAVA SRC -----------
-----------------------------------------------
package org.red5.server.webapp.TodayTonight;

import java.sql.*;

class mysql {

public static Connection conn = null;
public static void Connect(String User, String Pass, String Host, String DB)
{
try
{
//Class.forName("org.gjt.mm.mysql.Driver").newInstance();
Class.forName ("com.mysql.jdbc.Driver");
}
catch(Exception e)
{
System.out.println("Error: " + e);
}
//String url = "jdbc:mysql://"+Host+":3306/"+DB+"?user="+User+"&password="+Pass;
String url = "jdbc:mysql://localhost:3006/"+DB;
try
{
conn = DriverManager.getConnection (url, User, Pass);
//conn = DriverManager.getConnection (url);
System.out.println ("Database connection established");
}
catch (SQLException ex)
{
System.out.println("Connection was not established");
System.out.println("SQLException: " + ex.getMessage());
System.out.println("SQLState: " + ex.getSQLState());
System.out.println("VendorError: " + ex.getErrorCode());
System.out.println("\n\n***** START STACK ******\n");
ex.printStackTrace();
System.out.println("\n***** END STACK ******");
}
}
public static void Disconnect()
{
if (conn != null)
{
try
{
conn.close ();
System.out.println ("Database connection terminated");
}
catch (Exception e) {}
}
}

public static void main (String[] args)
{
Connect("root","<password>","localhost","mysql");
}
}
-----------------------------------------------
--------------- END JAVA SRC ------------
-----------------------------------------------

Any light on this issue would be great

PS: my testing server is on the same PC running XP Pro SP2 and using MYSQL 5.0 and JAVA jdk 1.6

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Posted
Communications link failure
January 16, 2008 01:14AM
January 17, 2008 10:10AM
February 02, 2008 08:03AM
January 19, 2009 11:24PM


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