Open a TCP connection to Cloud SQL for SQL Server by using Java.

## Explore further


For detailed documentation that includes this code sample, see the following:

- [Connect from App Engine flexible environment](https://docs.cloud.google.com/sql/docs/sqlserver/connect-app-engine-flexible.md.txt)
- [Connect from App Engine standard environment](https://docs.cloud.google.com/sql/docs/sqlserver/connect-app-engine-standard.md.txt)
- [Connect from Cloud Build](https://docs.cloud.google.com/sql/docs/sqlserver/connect-build.md.txt)
- [Connect from Cloud Run](https://docs.cloud.google.com/sql/docs/sqlserver/connect-run.md.txt)
- [Connect from Cloud Run functions](https://docs.cloud.google.com/sql/docs/sqlserver/connect-functions.md.txt)
- [Connect using the Cloud SQL Auth Proxy](https://docs.cloud.google.com/sql/docs/sqlserver/connect-auth-proxy.md.txt)

## Code sample

### Java


To authenticate to Cloud SQL for SQL Server, set up Application Default Credentials.
For more information, see

[Set up authentication for a local development environment](https://docs.cloud.google.com/docs/authentication/set-up-adc-local-dev-environment.md.txt).

```java

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;
import javax.sql.DataSource;

public class TcpConnectionPoolFactory extends ConnectionPoolFactory {

  // Note: Saving credentials in environment variables is convenient, but not
  // secure - consider a more secure solution such as
  // Cloud Secret Manager (https://cloud.google.com/secret-manager) to help
  // keep secrets safe.
  private static final String DB_USER = System.getenv("DB_USER");
  private static final String DB_PASS = System.getenv("DB_PASS");
  private static final String DB_NAME = System.getenv("DB_NAME");

  private static final String INSTANCE_HOST = System.getenv("INSTANCE_HOST");
  private static final String DB_PORT = System.getenv("DB_PORT");


  public static DataSource createConnectionPool() {
    // The configuration object specifies behaviors for the connection pool.
    HikariConfig config = new HikariConfig();

    // Configure which instance and what database user to connect with.
    config.setJdbcUrl(
        String.format("jdbc:sqlserver://%s:%s;databaseName=%s", INSTANCE_HOST, DB_PORT, DB_NAME));
    config.setUsername(DB_USER); // e.g. "root", "sqlserver"
    config.setPassword(DB_PASS); // e.g. "my-password"


    // ... Specify additional connection properties here.
    // ...

    // Initialize the connection pool using the configuration object.
    return new HikariDataSource(config);
  }
}
```

## What's next


To search and filter code samples for other Google Cloud products, see the
[Google Cloud sample browser](https://docs.cloud.google.com/docs/samples.md.txt?product=cloudsqlforsqlserver).