i just keep getting Connection Failed, i dont know why, im running a server on UniServerZ and trying to get the SQL file from localhost.
Im using uniserverZ (Unicontroller.exe) and i made the .sqlite file using SQLite manager addon for firefox. Anyone can help me out here? Thanks!
Edit: Ok, now im just trying to load the sqlite file from my C drive, i have commented out the command that would load it from my localhost because it doesnt work either. Any help?
package ui;
import java.sql.*;
import javax.swing.*;
public class MySQLConnect {
Connection conn=null;
public static Connection ConnectDb(){
try{
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:C:\\UniServerZ\\home\\Database\\db");
// Connection conn = DriverManager.getConnection("jdbc:mysql:\\localhost:3306\\Database\\db\\student.sql","root","root");
JOptionPane.showMessageDialog(null, "Connection Successful!");
return conn;
} catch(Exception e){
JOptionPane.showMessageDialog(null, "Connection Failed");
return null;
}
}
}
This connection is strange
jdbc:mysql://localhost:3306//Database//student.sql
try
"jdbc:mysql://localhost:3306/Database",userName,password
where Database is the real data base name.
Note also single / vs //
You work with Sqlite database but used the jar of Mysql..
So correct this line.
String driver = "com.mysql.jdbc.Driver";
to
String driver = "org.sqlite.JDBC";
Change url and add the sqlite jdbc driver to succesfull connection with Sqlite DB.
And remove one / from below line after . jdbc:sqlite: need only / .
Connection conn = DriverManager.getConnection("jdbc:sqlite://localhost/Database/db/database.sqlite");
Thanks..
Related
hello i am trying to connect my application to online database using the following code
import javax.swing.*;
import java.sql.*;
public class javacon {
Connection con = null;
private static final String url ="jdbc:mysql:\\sql204.byethost9.com:3306\\";
private static final String dbName = "b9_16134488_db";
private static final String userName = "b9_16134488";
private static final String password = "123.321";
public static Connection connectDB(){
try{
Class.forName("com.mysql.jdbc.Driver");
Connection con =DriverManager.getConnection("jdbc:mysql://sql204.byethost9.com:3306/b9_16134488_db/",userName,password);
JOptionPane.showMessageDialog(null, "connection is succseful");
return con;
}catch(Exception e){
JOptionPane.showMessageDialog(null, e);
return null;
}
}
}
but i am getting error says the driver has not received any packet
from the server
i found one answer this one says i have to go to my cpanel in my host and add my ip address there but i need every user to be connect to the database to login and logout
Mysql database has file my.cnf where bind-address might be specified. If that is not there, then mysql bind itself to all interfaces, otherwise only to specified one. More about this Bind-address
Also I guess user must have permissions to connect to database. 'user'#'ipaddress'. And more you can read here Connection access
Your code seems fine, your problem probably is related with your MySQL database not allowing connections from your host. The easiest way to find if this is the problem is trying to connect to the database from the same machine with the same credentials with MySQL Workbench.
There are three main things that can block your MySQL from receiving external connections:
1) Configuration
Edit my.cnf removing the following line:
bind-address = 127.0.0.1
2) User Host
In MySQL all users have defined from which host the connection can home from. 'user'#'%' would allow you to connect from any host.
3) Firewall
Make sure that the port 3306 is open.
Here's my code:
import java.sql.*;
public class DBConnector {
private static Connection conn;
public static void connectToDB()
{
//load the driver
try
{
Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
System.out.println ("Driver successfully loaded");
}
catch (ClassNotFoundException c)
{
System.out.println ("Unable to load database driver");
}
//connect to the database
try
{
String filename = "TopYouTubeVideos.mdb";
String database = "jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=";
database += filename.trim () + ";DriverID=22;READONLY=true}";
conn = DriverManager.getConnection (database, "", "");
System.out.println ("Connection database successfully established");
}
catch (Exception e)
{
System.out.println ("Unable to connect to the database");
}
}
The output is:
Driver successfully loaded
Unable to connect to the database
This has worked on a different computer than mine, connecting to the database through exactly the same code... does anyone have any idea why?
Thanks in advance :)
EDIT: I'm running Access 2007, Windows 7 64bit
By checking for the error, I get: java.sql.SQLException: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
From a little bit of research it seems this is a problem with my 'data source name'. I put my database file in the project folder, and the name is correct. Why is it not finding it?
EDIT: No, the database was the same on both computers. In the same folder as well.
EDIT: I think I may need to create a system dsm. Following the instructions on the internet dosent work though, because I dont have the same files as them..
EDIT: I've tried to install that but it hasn't made a difference. My version of access is 64 bit alongside my version of netbeans..
Try installing a database engine + JVM that are both running in the same archeticture (i.e. 32bit), otherwise, you would receive a mismatch exception. I assume your JVM is 64bit but your database engine is not, so try installing a 64bit engine from the following link:
http://www.microsoft.com/en-us/download/details.aspx?id=13255
This question already has answers here:
The infamous java.sql.SQLException: No suitable driver found
(21 answers)
Closed 7 years ago.
When trying to connect to mysql I always get this error:
java.sql.SQLException: No suitable driver found for localhost test
I already included the mysql-connector.jar in the /WEB-INF/lib in my app. What else do I need to configure to make it work? Do I need to add something in web.xml? I'm not using the appengine.
Here is my code in the server:
package com.mysql.server;
import java.sql.Connection;
import java.sql.DriverManager;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.mysql.client.ConnDb;
public class ConnDbImpl extends RemoteServiceServlet implements ConnDb {
public Connection con;
#Override
public String tryConn() {
try{
String host = "localhost";
String db = "test";
String driver = "com.mysql.jdbc.Driver";
String user = "root";
String pass = "pwd";
Class.forName(driver).newInstance();
con = DriverManager.getConnection(host+db, user, pass);
return "Connected to Database";
} catch(Exception ex) {
return ex.toString();
}
}
}
You will get this exception when the JDBC URL is not accepted by any of the loaded JDBC drivers as per the Driver#acceptsURL() method. You actually forgot the JDBC driver specific URI prefix. For the MySQL JDBC driver this is jdbc:mysql://. The full connection URL should look like this:
con = DriverManager.getConnection("jdbc:mysql://localhost/test", user, pass);
See also:
Connector/J documentation - Obtaining a connection
I found another cause for this error message. In my case the user simply had no privilege to the database e.g. to the selected table. Dear driver developers, why do you use such misleading error messages? A lot of people have real trouble with this.
For me, it was forgetting to include the MySQLJDBC Driver in the project libraries. DOH!
This was giving that error:
Connection connection= DriverManager.getConnection("jdbc:mysql://localhost:3306/lib_db","root","root");
but when I changed that to:
Connection connection =DriverManager.getConnection("jdbc:mysql://localhost/db_name?"+"user=root&password=root");
error was gone
I am working on a dynamic webapp on eclipse and is trying to access a remote MySQL database. I made sure that all the information is correct. However I can't seem to connect to it. Here's my getConnection method:
public static Connection getConnection() throws SQLException {
Connection conn = null;
try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
String url = "jdbc:mysql://50.56.81.42:3306/GUEST_BOOK";
String user = "username";
String password = "password";
conn = DriverManager.getConnection(url, user, password);
System.out.println("CONNECTED");
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(InstantiationException e){
e.printStackTrace();
}catch(IllegalAccessException e){
e.printStackTrace();
}
return conn;
}
I am trying to see what the error is but because this is a web app, I can't see that system.out.println anywhere, so it's kind of hard for me to debug with this. Any suggestions on how to debug?
Is your MySQL server accessible from out of the server? I am asking because it is possible to disable external connection for MySQL server, more info is here.
Your credentials are OK (at least its format).
Otherwise, you create Class.forName("com.mysql.jdbc.Driver").newInstance(); but you don't assign it to conn variable.
In web applications, System.out prints to the server's logs file. If you are using tomcat, see logs directory inside tomcat's base directory.
If you are still struggling to see the System out in logs, try to test the class from standalone java class, you will clearly see what the problem is.
So I have a MySQL database set up on a Debian server and it works fine from a phpMyAdmin client. I'm currently working on a project to write a Java server that would be able to use the MySQL database that is already on this server through a JDBC connection. I've looked at many tutorials and documentations but all of them seem to just explain how to do client-side code, but I have yet to figure out how to even successfully open a JDBC connection to the server. As far as I am concerned, I believe that program has the drivers properly set up because it's not crashing anymore (I simply direct the Java Build Path of my program to the Connector/J provided by MySQL). As far as my program goes, this is what it looks like...
import java.sql.*;
public class JDBCTest {
public static void main(String[] args) {
System.out.println("Started!");
try {
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
System.out.println("Driver registered. Connecting...");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/", "root", "password");
System.out.println("Connected!");
conn.close();
} catch (SQLException e) {
System.out.println("Error!");
e.printStackTrace();
}
}
}
This is what's printed...
Started!
Driver registered. Connecting...
It's as if the DriverManager.getConnection(String) just freezes there. I'm sure this is a problem with the server because when I intentionally misspell localhost, or an IP address, the program crashes within 20 seconds. This just hangs there forever.
Sorry about this wall of text, but my final question is if anyone has any information what I should do or install on the server to get this to work? Thank you so much!
Try following:
public class MySqlDemo {
public static void main(String [] args) {
java.sql.Connection conn = null;
System.out.println("SQL Test");
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = java.sql.DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test?user=root&password=");
}
catch (Exception e) {
System.out.println(e);
System.exit(0);
}
System.out.println("Connection established");
}
You have to provide the name of the Schema to which you are connecting. Usually, the port is also added.
This is a sample connection string:
jdbc:mysql://repos.insttech.washington.edu:3306/johndoe?user=johndoe&password=jddb
3306 is the port and the first instance of johndoe is the name of the Schema. The second instance of johndoe is the username.
It could be that the Connector/J library is trying to use a named pipe to connect to the MySQL server rather than using TCP/IP and for some reason the named pipe isn't available. Try specifying a port number.
You may also want to try turning on some logging in Connector/J's configuration as described here.
Try putting port number and schema there
Try logging into database using some SQL client, may be SQL console
Try other drivers, may be some newer or perhaps older