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Failure while connecting to MS SQL server

Trying to connect o MS SQL server that runs on the same Win 10 machine with my project in Eclipse:
String url = "jdbc:sqlserver://GOLD\\SQLEXPRESS;databaseName=PrintLog;";
Connection conn = DriverManager.getConnection(url ,"user","passwd");
But got exception:
com.microsoft.sqlserver.jdbc.SQLServerException: The connection to the host GOLD, named instance sqlexpress failed. Error: "java.net.SocketTimeoutException: Receive timed out". Verify the server and instance names and check that no firewall is blocking UDP traffic to port 1434. For SQL Server 2005 or later, verify that the SQL Server Browser Service is running on the host.
Computer name is GOLD. I can connect to DB from C# without problem. Authentication is enabled both windows and SQL server. I'm expecting to get Windows authentication while connect
SQL server properties:
How to find the problem?
UPD
I got better result by adding port number to connect string:
String url = "jdbc:sqlserver://GOLD\\SQLEXPRESS:1433;databaseName=PrintLog;";
Does it means that default port number is different?

connect amazon mysql with JDBC through remote server

I had a problem here, is it possible that JDBC connecting to the amazon MySQL server remotely? I searching on the Internet for solution but ended up receiving the error
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.
I am using jsch.jar to connect the remote server, then call up JDBC connector trying to connect MySQL DB, I had successfully connected to the remote server yet I cannot connect MySQL DB on amazon, here is my code
testPutty t = new testPutty();
t.connect("admin", "", "xx:xx:xx:xx", "openSSHPrivateKey", 22);
t.connect();
System.out.println("connected");
Class.forName("com.mysql.jdbc.Driver");
DriverManager.getConnection("jdbc:mysql://staging.ppyhcsxnlkji.ap-southwest-1.rds.amazonaws.com:3306/staging","superuser","password");
System.out.println("hello world");
t.close();

First set up the tunnel with SSH. You haven't shown what testPutty is so I'll assume it's a thin Java wrapper around a command line invocation of Putty. The command line option for setting up a tunnel is
-L[localport]:[host]:[remoteport]
For your example this would be
-L3306:staging.ppyhcsxnlkji.ap-southwest-1.rds.amazonaws.com:3306
This sets up a tunnel that forwards connections to local port 3306 to port 3306 on the given host (staging...amazonaws.com) on port 3306, routed through the host that is the target of the SSH command (in your sample xx:xx:xx:xx).
Then, your connection string needs to use localhost instead of the actual remote:
jdbc:mysql://localhost:3306/staging
If 3306 on your local host is not available because you are also running a local copy of MySQL, just choose a different unused port.

JDBC MySQL automatically converts localhost to 127.0.0.1

I am trying to connect to MySQL from JDBC via localhost. But the connection fails. In the exception, I see that JDBC is trying to connect to 127.0.0.1
String connectionString = "";
try {
loadProperties();
Class.forName("com.mysql.jdbc.Driver");
// Setup the connection with the DB
connectionString = "jdbc:mysql://" + properties.getProperty("host") + "/" + properties.getProperty
("database") + "?user=" + properties.getProperty("user") + "&password=" + properties
.getProperty
("password");
connect = DriverManager
.getConnection(connectionString);
logger.debug("Connected to " + properties.getProperty("host"));
} catch (Exception e) {
logger.error("Database Connection failed with connection string - " + connectionString,e);
}
From the log:
Database Connection failed with connection string - jdbc:mysql://localhost/testdb?user=testuser&password=testpass
java.sql.SQLException: Access denied for user 'testuser'#'127.0.0.1' (using password: YES)
Why is it replacing localhost with 127.0.0.1? I have configured login only for localhost.

I stumbled across this question when encountering the same issue.
To answer the question "Why is it replacing localhost with 127.0.0.1?":
From the MySQL docs, using localhost in your connection URL implies that you want to connect to a socket. Using 127.0.0.1 implies that you want to connect through TCP/IP.
On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. ... To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of 127.0.0.1
According to this answer, it appears that by default JDBC only supports TCP/IP connections, at least for some Java versions. Original source: http://lists.mysql.com/java/8749:
Java itself doesn't support unix domain sockets
So, I'd guess that since JDBC only connects through TCP/IP, it converts localhost to 127.0.0.1 internally.
To solve the problem in my case:
I granted permission in MySQL for user#127.0.0.1
I changed localhost to 127.0.0.1 in my connection URL.

The IP address 127.0.0.1 is a special purpose address reserved for use on each computer. 127.0.0.1 is conventionally a computer's loopback address.
Network software and utilities can use 127.0.0.1 to access a local computer's TCP/IP network resources. Messages sent to loopback IP addresses like 127.0.0.1 do not reach outside to the local area network (LAN) but instead are automatically re-routed by the computer's own network adapter back to the receiving end of the TCP/IP stack. In simple words, localhost can also be referred as 127.0.0.1. There is a problem with MySql access privileges. This link would help you resolve it

Database connection string for a remote database server named 'localhost'

I have a remote mysql database server setup on a machine myuniversity.edu and server is named 'localhost'. On it I have the database named 'MyDatabase'.
I want to connect it through Java.
The connection urls that I have tried are:
jdbc:mysql://myuniversity.edu/localhost
jdbc:mysql://myuniversity.edu/localhost/MyDatabase
jdbc:mysql://myuniversity.edu:3306/MyDatabase
but I get the `Connection refused: connect` exception.
Could someone please tell what the connection url should be in this case?

Not really sure if your machine name is myuniversity.edu, you can instead try the IP Address with the connection string, Localhost is the name for loopback network interface and accessible on that machine only. Also make sure if your default port for mysql (may be 3306) is open. With IP address your connection string would look like:
jdbc:mysql://192.168.0.123/MyDatabase
With IP and port it would be:
jdbc:mysql://192.168.0.123:3306/MyDatabase
(You need to replace your IP in the above string)

I'ts impossible to connect remotely without (IP) address
try this approach
if you want to connect it via internet :
OPEN CMD on your computer
in CMD write ping myuniversity.edu (for example ping google.com)
then you will get an ip address of the website and you can copy the ip
then try this approach :
Connection con;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://THE IP ADDRESS :3306/DatabaseName");
System.out.println("CONNECTED");
}catch(Exception ex)
{
System.out.println(ex.getMessage());
}

Ok so here's what I did to fix the issue:
In my.cnf file, I changed the bind-address from '127.0.0.1' to the
'host ipaddress'. This allows connecting to the remote mysql server
but would not allow access for any remote host trying to connect to
it.
To fix that, I added an entry in user table with host '%'. This allows remote hosts to connect to the database.
Now I can connect to the database with jdbc:mysql://serverIpAddress:3306/MyDatabase

Connecting to external database using java

I have a java program that connects to a MS SQL database. The program works perfectly when running through eclipse however I get an error when I run it through AIX:
java.sql.SQLException: Network error IOException: A remote host refused an attempted connect operation.
I am using jtds to connect:
String connectionString = "jdbc:jtds:sqlserver://"+dropez_ip_address+"/"+dropez_db_name;
ResultSet rs = null;
Statement stmt = null;
try{
Class.forName("net.sourceforge.jtds.jdbc.Driver");
Connection conn = DriverManager.getConnection(connectionString, dropez_db_username, dropez_db_password);
stmt = conn.createStatement();
}catch(Exception e){}

From jTDS documentation:
Why do I get java.sql.SQLException: "Network error IOException: Connection refused: connect" when trying to get a connection?
The "Connection refused" exception is thrown by jTDS when it is unable to connect to the server. There may be a number of reasons why this could happen:
The server name is misspelled or the port number is incorrect.
SQL Server is not configured to use TCP/IP. Either enable TCP/IP from SQL Server's Network Utility app or have jTDS connect via named pipes (see the URL format for information on how to do this).
There is a firewall blocking port 1433 on the server.
To check whether TCP/IP is enabled and the port is not blocked you can use "telnet 1433". Until telnet doesn't connect, jTDS won't either. If you can't figure out why, ask your network administrator for help.
My bet is your firewall does not allow the AIX host to connect.