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Failed to get driver instance for jdbcUrl=jdbc:postgresql:///<dbname> error for CloudSQL

I am trying to connect to my GCP projects PostgreSQL CloudSQL instance from my local machine. The PostgreSQL doesn't have a public IP, only private.
Properties connProps = new Properties();
connProps.setProperty("user", "XXX-compute#developer.gserviceaccount.com");
connProps.setProperty("password", "password");
connProps.setProperty("sslmode", "disable");
connProps.setProperty("socketFactory", "com.google.cloud.sql.postgres.SocketFactory");
connProps.setProperty("cloudSqlInstance", "coral-XXX-XXXX:us-central1:mdm");
connProps.setProperty("enableIamAuth", "true");
HikariConfig config = new HikariConfig();
config.setJdbcUrl(jdbcURL);
config.setDataSourceProperties(connProps);
config.setConnectionTimeout(10000); // 10s
HikariDataSource connectionPool = new HikariDataSource(config);
I get the below error
Failed to get driver instance for jdbcUrl=jdbc:postgresql:///mdm
java.sql.SQLException: No suitable driver
I have verified that my username, instancename, IAM connectivity is all working fine. The IAM service account I am using is my compute engine's default service account.
Should I be able to connect to this PostgreSQL instance from my local machine?

First, make sure you're configuring your JDBC URL correctly.
The URL should look like this:
jdbc:postgresql:///<DATABASE_NAME>?cloudSqlInstance=<INSTANCE_CONNECTION_NAME>&socketFactory=com.google.cloud.sql.postgres.SocketFactory&user=<POSTGRESQL_USER_NAME>&password=<POSTGRESQL_USER_PASSWORD>
See the docs for details.
Second, if your Cloud SQL instance is Private IP only, your local machine won't have a network path to it, unless you've explicitly configured one (see this answer for options).
Generally, the simplest way to connect to a private IP instance is to run a VM in the same VPC as the instance, and connect from that VM.

While it is a good practice from the security point to have only the private IP enabled and remove the public IP from the Cloud SQL instance, there are some considerations to be kept in mind when thinking about the connectivity.
With the Cloud SQL instance having only the private IP enabled there is no direct way in which you can connect to it from the local machine, neither by using private IP nor by using Cloud SQL proxy.
Now, in your case, as you mentioned you have only private IP enabled in the Cloud SQL instance, it seems to be the reason you are getting the error.
To mitigate the error -
If possible, I would suggest you provision a public IP address
for the Cloud SQL instance and then try to connect it by correctly
specifying the jdbc URL as mentioned here, which looks something like this -
jdbc:postgresql:///<DATABASE_NAME>?cloudSqlInstance=<INSTANCE_CONNECTION_NAME>&socketFactory=com.google.cloud.sql.postgres.SocketFactory&user=<POSTGRESQL_USER_NAME>&password=<POSTGRESQL_USER_PASSWORD>
Else, if you don’t want to provision a public IP address, to
establish the connection from an external resource you can make use
of a Cloud VPN Tunnel or a VLAN attachment if you have a Dedicated
Interconnect or a Partner Interconnect as mentioned here.
If you don’t have a Dedicated Interconnect or a Partner Interconnect and you want to use the private IP only then, to connect to the Cloud SQL you can enable port forwarding via a Compute Engine VM instance. This is done in two steps -
Connect the Compute Engine to the Cloud SQL instance via the private IP.
Forward the local machine database connection request to the Compute Engine to reach the Cloud SQL instance through Cloud SQL Proxy tunnel. This youtube video describes how to do this.
To get a detailed description of the above you can go through this article.

How to connect opc kepware server through a Java program, without the username and the password?

I am trying to connect opc kepware server through a Java program, I want to know what jar files can be used to connect to KepwareserverEx.V5 and what is the code without the use of password and username.
I have referenced http://www.opcconnect.com/uakit.php, and https://github.com/digitalpetri/ua-server-sdk, but it doesn't have anything that doesn't connect without a username and a pawssword. I have a program in vb that connects to kepware using Interop.OPCAutomation.dll file and uses the code:
ConnectedOPCServer = New OPCAutomation.OPCServer
ConnectedOPCServer.Connect("Kepware.KEPServerEX.V5", "")
ConnectedGroup = ConnectedOPCServer.OPCGroups.Add("MPM Group")
ConnectedGroup.UpdateRate = 1000
ConnectedGroup.IsSubscribed = True
ConnectedGroup.IsActive = True
I want to write Java code in a similar way. Searched through the internet to see various examples, but none have the above connection without a username and password not being specified.

First of all, I assume that you have created an "anonymous" and "SecurityPolicy.None" endpoint on KepServerEX.
You refer to digitalpetri's old and server SDK. The new project is called "Milo". I can recommend you take a look at the Milo project's client SDK examples using this link. There is an application of anonymous identity and none security policy.
In terms of jar, you can either build your client-sdk (see example here) or directly download the client-sdk jar from Maven Central.
NB Milo is considered to be in incubation. That is to say, it is not mature yet. Be careful using it in production systems.

Yes that's right. The security policy is none on the KepwareServerEX. I made some permission changes on the server where Kepware exists, so that my localhost computer would be able to talk to the Kepware server host. Provided credentials for my localhost, and able to connect.

connecting java application with online hosted mysql database

I have build an application in java, application is one and will be used on 3 different systems,And therefore the database of that application must be online to keep all 3 applications with up to date database...
In starting I developed my application based on localhost (wampserver) and used database in "PhpMyAdmin", and hopefully application is fully developed and ready to run.. but the problem is online database connectivity!
I have uploaded my database on a Site in PhpMyAdmin and they provided below information:
and the for connecting my app to this DB is:
String url = "jdbc:mysql://fdb12.biz.nf:3306/";
String dbName = "1738412_wstore";
String driver = "com.mysql.jdbc.Driver";
String userName = "1738412_wstore";
String password = "Password";
Class.forName(driver).newInstance();
Connection conn = DriverManager.getConnection(url+dbName,userName,password);
now when I run my application it shows below error:
I dont know what the problem is there, please help me out through this..

I faced the same issue and the following helped me to solve.
http://support.hostgator.com/articles/cpanel/how-to-connect-to-the-mysql-database-remotely
Hopefully, your hosting provider should have same type of cpanel to configure MySQL database for remote connections.

Check for firewall.
Check if mysql is running.

2 things you can try:
Install MySql client locally on your machine and connect like: mysql -h fdb12.biz.nf -u 1738412_wstore -P<password>
This should work before you try anything else.
Make sure you're using the right imports in your code. See [here][1].
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

I think your DB server doesn't allow remote connections.
Try hosting in:
http://www.freesqldatabase.com/freemysqldatabase/
It's free and allow remote DB connections.
Good Luck!!!

Considering the Biz.nf FAQ:
How can I connect to my MySQL/PostgreSQL database? What settings
should I use for my script/software?
MySQL/PosgreSQL database connection can be established with script/software hosted only on your
web hosting account (meaning no remote access is allowed due to
security reasons). The following settings are needed:
So, since biz.nf does not allow remote access, it will be difficult for you to interact with their MYSQL server for your application.
The best solution and the most simple is probably to find a new provider which will allow the remote access. Heroku.com works very well.
If you really want to use the biz.nf services, it will be more difficult.
It's not a script or credential problem.
Maybe you can (probably not), try to login by SSH to configure your server to enable remote access to your MYSQL database server.
From the free plan, you will not have any access to the online SSH tool and you will need to configure your domain for a SSH connection.
In SSH, and it probably will not work considering the FAQ, you could try to simply modify your /etc/mysql/my.cnf file by commenting the bind-address line wich by default only allows local access (127.0.0.1). Then, try to restart your MYSQL service with: a simple service mysql restart to verify if the remote connection works.
If the remote connection still doesn't work after this, the only way I can find for the moment (unless you completely change your hosting provider) would be to create a kind of API hosted directly on the server and your Java program could interacts with your services (In JSON, by example).

Android + JDBC: No route to host (it works on the desktop, why not on android?)

I've searched through the site and haven't quite found a post that answers my problem.
I wrote a desktop application (Java/swing/JDBC) to connect to a local database via JDBC. This database is hosted on an IBM i-series (AS400) (though I'm quite certain this isn't an as400-only problem) and is only available on the internal network. I'm working on translating that application into an android app to be used onside in the warehouse via wireless connection.
I have my JDBC connection in it's own thread. The app asks the user for username/password before attempting a connection. The connection fails every time with the same message: java.sql.SQLException: The application requester cannot establish the connection. (No route to host)
Here is the offending code:
try
{
// Use the AS400 driver.
DriverManager.registerDriver(new com.ibm.as400.access.AS400JDBCDriver());
// Now connect
connection = DriverManager.getConnection(
"jdbc:as400://" + IP_ADDRESS + "/" + SCHEMA +
";naming=sql;errors=full",
USER_ID, PASSWORD);
System.out.println("Connection established using the AS400 driver(s)");
}
catch(Exception as400)
{
String message = "Error setting driver and connection using\n "
+ "the AS400 drivers. The error message is as follows:\n "
+ as400.getMessage();
System.out.println(message);
throw new Exception(message);
}
It registers the driver then hits No route to host, pauses for a second, then throws an error, completely stalling the device instead of letting my error handler safely close the app.
I have double (triple) checked to ensure the credentials are correctly passed and the IP and schema are both correctly set. This code is a direct copy of my desktop code. The only difference is I use a jar optimized for android instead of the desktop. The jar simply contains a translation layer between native AS400 code and Java, but works the same as any SQL jar.
This is our primary database server used throughout the entire company. It is always available and SQL is enabled on it. I am testing this using a physical android device (not an emulated one) and it is connected to our internal wireless network.
Any suggestions on how to fix this or even a direction to look in? Why is there such a difference between the desktop and my android despite both using JDBC? Do I need to do something special for address resolution or something similar? Google-fu is failing me badly. Thanks for your help!

It's not uncommon for wireless traffic to be restricted due to corporate security policies.
Verify that you can connect to DRDA (tcp port 446) on the IBM i from the device on the wireless network.
See TCP/IP Ports Required for iSeries Access for Windows for more information.
JTOpen/Toolbox has a proxy mode if security requirements prevent allowing direct access to the IBM i.
The lightweight version of the JTOpen/Toolbox jar's are also more suited to installation in a cpu and memory restricted environment such as an Android device.
The full JTOpen/Toolbox can be run as a proxy server as follows:
java -cp jt400.jar com.ibm.as400.access.ProxyServer -verbose -port 3470
Add the proxy server option to your connection string:
jdbc:as400:<url>;proxy server=<proxy server address:port>

Play! framework - Cannot connect to database

this is the error I get when I'm trying to connect to my local postgresql db:
Cannot connect to database [default]
this is the database configuration. I'm convinced that there is not typo (fat finger error):
db.default.url="postgres://localhost:5432/myproject/"
db.default.user="postgres"
db.default.pass="mypassword"
db.default.driver="org.postgresql.Driver"
db.default.initSQL="SELECT 1"
where is the problem? with pgAdmin I can connect easily
p.s.
I'm using ubuntu. I've noticed that in order to change to postgres user
I must use "su", otherwise it fails changing the current user.
is that has something to do with play! failure to connect my db?
thanks

There might be two things wrong or at least dubious in your setup.
First: The postgres:... URL syntax is not a plain JDBC URL. This format is not understood by the PostgreSQL JDBC driver. See this answer to a similar problem.
Second: You are trying to use the PostgreSQL superuser account for Play. The superuser account should be used only for administrative work, but not "normal" work. Especially not for work which includes public access to the DB via some webfrontend. Any SQL-Injection attack gives the attacker the golden key to your database - including the nuke to wreck your complete DB cluster at once or install any backdoor into you DB server.
So I recommand, that you create a new user which you configure in your Play! settings.
That said: The default password for the postgres user is not set on Ubuntu. This setup allows login to the DB user only from the same OS user. How you can fix this is explained in this answer.
If these two tips don't help: The error you quoted is very vague. There must be more detailed error logs somewhere. Please find them and attach them to your question with the "edit" button.

This is not an answer directly to your question, but I had the same error message and came here via Google. Using Scala Play 2.3, I had
db.default.driver=org.postgresql.Driver
db.default.url="jdbc:postgresql://127.0.0.1:5432/noob_development"
db.default.logStatements=true
which needed to be
db.default.driver="org.postgresql.Driver"
db.default.url="jdbc:postgresql://127.0.0.1:5432/noob_development"
db.default.logStatements=true
I accidentally left the quotes around the driver name out. Now it works perfectly.

here is my conf, it works:
db.default.url="jdbc:postgresql://127.0.0.1:5432/dbname"
db.default.driver="org.postgresql.Driver"
just add the jdbc: before postgresql in db.default.url.