java client

Author: davitbzh

docs/user_guides/integrations/index.md

@@ -3,6 +3,7 @@
 Hopsworks is an open platform aiming to be accessible from a variety of tools. Learn in this section how to connect to Hopsworks from
 
 - [Python, AWS SageMaker, Google Colab, Kubeflow](python)
+- [Java](java)
 - [Databricks](databricks/networking)
 - [AWS EMR](emr/emr_configuration)
 - [Azure HDInsight](hdinsight)

docs/user_guides/integrations/java.md

@@ -0,0 +1,51 @@
+---
+description: Documentation on how to connect to Hopsworks from a Java client.
+---
+
+# Java client
+
+This guide explains step by step how to connect to Hopsworks from a Java client.
+
+
+## Generate an API key
+
+For instructions on how to generate an API key follow this [user guide](../projects/api_key/create_api_key.md). For the Java client to work correctly make sure you add the following scopes to your API key:
+
+  1. featurestore
+  2. project
+  3. job
+  4. kafka
+
+## Connecting to the Feature Store
+
+You are now ready to connect to the Hopsworks Feature Store from a Java client:
+
+```Java
+//Import necessary classes
+import com.logicalclocks.hsfs.FeatureStore;
+import com.logicalclocks.hsfs.FeatureView;
+import com.logicalclocks.hsfs.HopsworksConnection;
+
+//Establish connection with Hopsworks.
+HopsworksConnection hopsworksConnection = HopsworksConnection.builder()
+  .host("my_instance")                      // DNS of your Feature Store instance
+  .port(443)                                // Port to reach your Hopsworks instance, defaults to 443
+  .project("my_project")                    // Name of your Hopsworks Feature Store project 
+  .apiKeyValue("api_key")                   // The API key to authenticate with the feature store
+  .hostnameVerification(false)               // Disable for self-signed certificates
+  .build();
+
+//get feature store handle
+FeatureStore fs = hopsworksConnection.getFeatureStore();
+
+//get feature view handle
+FeatureView fv = fs.getFeatureView(fvName, fvVersion);
+
+// get feature vector
+List<Object> singleVector = fv.getFeatureVector(new HashMap<String, Object>() {{
+        put("id", 100);
+        }});
+```
+
+## Next Steps
+For more information how to interact from Java client with the Hopsworks Feature store follow this [tutorial](https://github.com/logicalclocks/hopsworks-tutorials/tree/java_engine/java).