Creating a Session for Snowpark Java (original) (raw)

To use Snowpark in your application, you need to create a session. For convenience in writing code, you can also import the names of packages and objects.

Importing Names from Packages for Snowpark¶

The Snowpark API provides a number of classes in different packages. For convenience, you can import these packages to avoid having to use qualified names for classes.

For example:

• The com.snowflake.snowpark_java package contains the main classes for the Snowpark API. To import the names in this package:
  import com.snowflake.snowpark_java.*;
• The com.snowflake.snowpark_java.types package defines classes that you can use to define schemas for semi-structured data.
  import com.snowflake.snowpark_java.types.*;

Creating a Session for Snowpark¶

The first step in using the library is establishing a session with the Snowflake database. To create a session, use the methods in the SessionBuilder class. You can access a SessionBuilder object by calling the static builder method in the Session class:

import com.snowflake.snowpark_java.*;

... // Get a SessionBuilder object. SessionBuilder builder = Session.builder();

To provide the details to establish a session with a Snowflake database (for example, the account identifier, user name, etc.), either create a properties file (a text file) or programmatically build a Map containing the properties.

In the properties file or Map, set the following properties:

• URL: Set this to the URL for your account in the form https://_accountidentifier_.snowflakecomputing.com.
  See Account identifiers.
  If the account identifier contains underscores (_), replace those underscores with hyphens (-).
• Any additional JDBC parameters (see JDBC Driver connection parameter reference in the JDBC driver documentation) needed to connect to Snowflake (e.g. USER, ROLE, WAREHOUSE, DB, SCHEMA, etc.).
• (Optional) snowpark_request_timeout_in_seconds: Set this to the maximum number of seconds that the Snowpark library should wait in the following cases:
  • Waiting for dependencies to be uploaded to a stage.
  • Waiting for an asynchronous action to complete.
    The default value of this property is 86400 seconds (1 day).
    Note
    This property was introduced in Snowpark 0.10.0.

To authenticate, you can use the same mechanisms that the JDBC Driver supports. For example, you can use:

• password-based authentication (by setting the PASSWORD property)
• key-pair authentication
• single sign-on (SSO)

For key-pair authentication, you can either:

• Set the PRIVATE_KEY_FILE property to the path to the private key file.
  If the private key is encrypted, set the PRIVATE_KEY_FILE_PWD property to the passphrase for decrypting the key.
• Set the PRIVATEKEY property to the string value of the unencrypted private key from the private key file. (If the private key is encrypted, you must decrypt the key before setting it as the value of the PRIVATEKEY property.)

To create the session:

1. Set the properties in the SessionBuilder object.
   • If you created a properties file, pass the path to the properties file to the configFile method of theSessionBuilder object.
   • If you programmatically built a Map of the properties, pass the Map to the configs method of theSessionBuilder object.
     Both methods return a SessionBuilder object that has these properties.
2. Call the create method of the SessionBuilder object to establish the session.

The following is an example of a properties file that sets the basic parameters for connecting to a Snowflake database. The example is set up to use key-pair authentication. Set PRIVATE_KEY_FILE to the path to the private key file. In addition, if the private key is encrypted, you must set PRIVATE_KEY_FILE_PWD to the passphrase for decrypting the private key:

profile.properties file (a text file)

URL = https://.snowflakecomputing.com USER = PRIVATE_KEY_FILE = </path/to/private_key_file.p8> PRIVATE_KEY_FILE_PWD = <if the private key is encrypted, set this to the passphrase for decrypting the key> ROLE = WAREHOUSE = DB = SCHEMA =

As an alternative, you can set the PRIVATEKEY property to the unencrypted private key from the private key file.

profile.properties file (a text file)

URL = https://.snowflakecomputing.com USER = PRIVATEKEY = ROLE = WAREHOUSE = DB = SCHEMA =

The following example uses this properties file to create a new session:

// Create a new session, using the connection properties // specified in a file. Session session = Session.builder().configFile("/path/to/properties/file").create();

The following example uses a Map to set the properties:

import com.snowflake.snowpark_java.*; import java.util.HashMap; import java.util.Map; ... // Create a new session, using the connection properties // specified in a Map. // Replace the below. Map<String, String> properties = new HashMap<>(); properties.put("URL", "https://.snowflakecomputing.com:443"); properties.put("USER", ""); properties.put("PRIVATE_KEY_FILE", "</path/to/private_key_file.p8>"); properties.put("PRIVATE_KEY_FILE_PWD", "<if the private key is encrypted, set this to the passphrase for decrypting the key>"); properties.put("ROLE", ""); properties.put("WAREHOUSE", ""); properties.put("DB", ""); properties.put("SCHEMA", ""); Session session = Session.builder().configs(properties).create();

Closing a Session¶

If you no longer need to use a session for executing queries and you want to cancel any queries that are currently running, callclose method of the Session object. For example:

// Close the session, cancelling any queries that are currently running, and // preventing the use of this Session object for performing any subsequent queries. session.close();