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Connecting to local Mysql server from other pc

I have an local server which installed apache and mysql servers. both of them works very well. I can display the apache default page on browser fine. And I can manage the mysql database via terminal. All okey for now. But if I try to write code to use my DB. It gives me communication link error.
Here is the simple JAVA code:
public static void main(String[] args) {
String url = "jdbc:mysql://192.168.1.49:3306/test";
String username = "root";
String password = "1234";
System.out.println("Connecting database...");
Connection connection = null;
try {
connection = DriverManager.getConnection(url, username, password);
System.out.println("Database connected!");
} catch (SQLException e) {
throw new IllegalStateException("Cannot connect the database!", e);
}
}
AND HERE IS THE ERROR:
Connecting database...
Exception in thread "main" java.lang.IllegalStateException: Cannot
connect the database! at
servermysql.ServerMysql.main(ServerMysql.java:34) Caused by:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:
Communications link failure
THE SERVER İS UBUNTU 14.04 SERVER
THANK YOU FRİENDS

You have to set MYSQL bind-address to 0.0.0.0 because it usually only listens on 127.0.0.1 by default executing following command:
sed -i -e”s/^bind-address\s*=\s*127.0.0.1/bind-address = 0.0.0.0/” /etc/mysql/my.cnf
Or manually change the bind-address to 0.0.0.0 in /etc/mysql/my.cnf and restart MYSQL.

Connection refused: connect, can't connect database mysql

I can't connect remote database. When I connect my own database on localhost, it connects. What's wrong?
Exception in thread "main" java.lang.IllegalStateException: Cannot connect the database!
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
Caused by: java.net.ConnectException: Connection refused: connect
Java Code:
String url = "jdbc:mysql://ipadress:3306/database?autoReconnect=true&useSSL=false";
String username = "username";
String password = "password";
String query = "SELECT * FROM database";
System.out.println("Connecting database...");
try {
// The newInstance() call is a work around for some
// broken Java implementations
Class.forName("com.mysql.jdbc.Driver").newInstance();
} catch (Exception ex) {
// handle the error
}
try (Connection connection = DriverManager.getConnection(url, username, password)) {
System.out.println("Database connected!");
//Uruchamiamy zapytanie do bazy danych
Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery(query);
while (rs.next()) {
}
connection.close();
} catch (SQLException e) {
throw new IllegalStateException("Cannot connect the database!", e);
}
}
I can login to database on PHPMyAdmin, I have no root account, it's my friend's database. I checked if port 3306 is open here: http://www.yougetsignal.com/tools/open-ports/ and it's closed. Where can I open it? In router settings in "port forwarding"? What private IP and type(TCP or UDP) should I set to open this port?

(Apologies if this answer is incomplete, but there is too much that does not fit in comments)
1) Don't ignore exceptions. This is bad : with // handle the error and nothing else in your catch block, in case of error there, your code will not report the error, and will move on with the execution (it should exit/break/return, depending on where that piece of code is).
2) I think checking "SHOW GLOBAL VARIABLES LIKE 'PORT';" is not enough. Ask your friend if the database daemon actually listens to port 3306 on a network interface that you can reach. MySQL can be configured with networking disabled (skip-networking), or enabled but only for local machine (bind-address=127.0.0.1 or localhost -- it should be bind-address=0.0.0.0 or bind-address=hostname or public IP address...).
To check for that yourself, if you are on linux, try with nc or telnet (install nc if you don't have it): nc remotehost 3306. If you get "connection refused", the error is definitely not in your java code, but in the server setup.

SQLException while connecting to Azure SQL Data Warehouse using JDBC

I am trying to connect to Azure SQL Data Warehouse through JDBC. I am getting the following exception.
*
com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host tcsqldatawh.database.windows.net, port 1433 has failed. Error: "null. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.".
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:191)
at com.microsoft.sqlserver.jdbc.SQLServerException.ConvertConnectExceptionToSQLServerException(SQLServerException.java:242)
at com.microsoft.sqlserver.jdbc.SocketFinder.findSocket(IOBuffer.java:2280)
at com.microsoft.sqlserver.jdbc.TDSChannel.open(IOBuffer.java:493)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1387)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:1068)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectInternal(SQLServerConnection.java:904)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:451)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:1014)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:270)
at testsqldw.SQLDatabaseConnection.main(SQLDatabaseConnection.java:30)
*
I have seen similar questions asked about connecting to the SQLServer DB here.
I configured the database to allow access to my IP using the process here.
Please check the code below:
package testsqldw;
import java.sql.*;
public class SQLDatabaseConnection {
// Connect to your database.
// Replace server name, username, and password with your credentials
public static void main(String[] args) {
String connectionString =
"jdbc:sqlserver://databaseserver.database.windows.net:1433;"
+"database=databaseserver;"
+"user=username#databaseserver;"
+ "password=password;"
+ "encrypt=true;"
+ "trustServerCertificate=false;"
+ "hostNameInCertificate=*.database.windows.net;"
+ "loginTimeout=30;";
System.out.println("Total connection string is---\n"+connectionString);
// Declare the JDBC objects.
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
try {
connection = DriverManager.getConnection(connectionString);
// Create and execute a SELECT SQL statement.
String createSql = "create table employee(employee_id varchar(20));";
statement = connection.createStatement();
boolean status=statement.execute(createSql);
System.out.println(status);
// Print results from select statement
}
catch (Exception e) {
e.printStackTrace();
}
finally {
// Close the connections after the data has been handled.
if (statement != null) try { statement.close(); } catch(Exception e) {}
if (connection != null) try { connection.close(); } catch(Exception e) {}
}
}
}
Total connection string is
jdbc:sqlserver://databaseserver.database.windows.net:1433;database=databaseserver;user=username#databaseserver;password=password;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30;
Please help me in resolving the issue.

Per my experience, the issue may be caused by the following reasons:
The SQL Server which you have created may not work fine.
You may use incorrect JDBC connection string.
For the first reason, you could use some client tools to connect to the SQL server. If you could connect to the server, that indicates the SQL server is ok.
If not ,you could create a new SQL Server. After then, you could create a new SQL Data Warehouse according to this URL https://azure.microsoft.com/en-us/documentation/articles/sql-data-warehouse-get-started-provision/.
The URL also includes the firewall config method.
I use the SQL Server InTouch to connect to the SQL Server. The followings are some description images.
You could get the parameters by the Azure Portal. The port number is 1433.
The following picture indicates that your server is ok.
For the second reason, you could copy the connection string from the azure portal and modify the password only.
Hope it helps. Any concerns, please feel free to let me know.

how to embed oracle XE database in executable jar?

I have developed java application using java swings and oracle XE database in "myecplise". I have also created executable jar file and it runs fine in my pc but it is showing jdbc.odbc ClassNotFound exception and NullPointer Exception in other pc
my connection code is
import java.sql.*;
public class Connect {
static Connection con=null;
public static Connection ConnectDB(){
try{
// Class.forName("oracle.jdbc.driver.OracleDriver");
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection con = DriverManager.getConnection("jdbc:oracle:thin:system/system#localhost");
return con;
}catch(Exception e){
JOptionPane.showMessageDialog(null, e.getMessage());
e.printStackTrace();
return null;
}
}
}

The DriverManager.getConnection("jdbc:oracle:thin:system/system#localhost") states that the driver manager will connect to the database located at your localhost. On the other PC it tries to locate the database on that other machine, since the database is not present there the exception will occur.
You have to change the connection to something like:
DriverManager.getConnection("jdbc:oracle:thin:#arg0:arg1:arg2", arg3, arg4);
Where
arg0: the IP of the machine that hosts the database.
arg1: The port that the database is listening to.
arg2: the SID of the database.
arg3: the schema username.
arg4: the schema password.

Unable to Connect with my Database 000webhost.com

try {
String connectionURL = "jdbc:mysql://sql4.000webhost.com/a7291194_xxx";
Connection connection = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL, "a7291194_xxx", "xxx");
if(!connection.isClosed())
System.out.println("Successfully connected to " + "MySQL server using TCP/IP...");
connection.close();
}catch(Exception ex){
System.out.println("Unable to connect to database"+ex);
}
With the following connector code I am trying to connect with the database on 000webhost.com but it gives me an error:
CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago.
The driver has not received any packets from the server.
I am trying my best for the first time as I am totally new to webhosting so please help me thanks in advance!

its same either on your local or on server
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql://DomainName OR IP:3306/databasename", "username", "password");

At 000webhost.com remote MySQL connections are disabled for security and server performance reasons.
If you upgrade your account, MySQL connections will be enabled.