Implementation:Risingwavelabs Risingwave JniCatalogWrapper LoadTable

Knowledge Sources	RisingWave Apache Iceberg
Domains	Data_Lake, Metadata_Management, Iceberg, JNI
Last Updated	2026-02-09 07:00 GMT

Overview

Concrete tool for performing Iceberg catalog operations via JNI bridge provided by the RisingWave Java connector node.

Description

JniCatalogWrapper provides JNI-accessible methods for Iceberg catalog operations. It wraps an Apache Iceberg Catalog instance (loaded via CatalogUtil.loadCatalog()) and delegates operations through CatalogHandlers (the Iceberg REST compatibility layer). All requests and responses are serialized as JSON strings for JNI transport.

Usage

This is called from the Rust engine via JNI when the Iceberg sink needs to create, load, update, or drop tables in the catalog.

Code Reference

Source Location

• Repository: risingwave
• File: java/connector-node/risingwave-sink-iceberg/src/main/java/com/risingwave/connector/catalog/JniCatalogWrapper.java
• Lines: L51-219

Signature

public class JniCatalogWrapper {
    public String loadTable(String tableIdentifier) throws Exception;
    public String createTable(String namespaceStr, String createTableRequest) throws Exception;
    public String updateTable(String updateTableRequest) throws Exception;
    public boolean tableExists(String tableIdentifier);
    public boolean dropTable(String tableIdentifier);
    public void createNamespace(String namespaceStr);
    public boolean namespaceExists(String namespaceStr);
    public String listNamespaces() throws Exception;
    public String listTables(String namespaceStr) throws Exception;
    public void close() throws Exception;

    public static JniCatalogWrapper create(
        String name,
        String klassName,
        String[] props
    );
}

Import

import com.risingwave.connector.catalog.JniCatalogWrapper;

I/O Contract

Inputs

Name	Type	Required	Description
name	String	Yes (for create)	Catalog name
klassName	String	Yes (for create)	Delegated catalog class (e.g., org.apache.iceberg.hadoop.HadoopCatalog)
props	String[]	Yes (for create)	Key-value pairs for catalog configuration
tableIdentifier	String	Yes (for loadTable)	Table identifier in format 'namespace.table'
createTableRequest	String (JSON)	Yes (for createTable)	Serialized CreateTableRequest
updateTableRequest	String (JSON)	Yes (for updateTable)	Serialized UpdateTableRequest

Outputs

Name	Type	Description
loadTable return	String (JSON)	Serialized LoadTableResponse with table metadata and location
createTable return	String (JSON)	Serialized LoadTableResponse for newly created table
updateTable return	String (JSON)	Serialized LoadTableResponse after update
tableExists return	boolean	Whether the table exists in the catalog

Usage Examples

Create Catalog and Load Table (Internal Java)

// Create a Hadoop-based catalog
JniCatalogWrapper catalog = JniCatalogWrapper.create(
    "demo",
    "org.apache.iceberg.hadoop.HadoopCatalog",
    new String[]{
        "warehouse", "s3://hummock001/iceberg-data",
        "io-impl", "org.apache.iceberg.aws.s3.S3FileIO"
    }
);

// Load a table
String tableJson = catalog.loadTable("demo_db.demo_table");
// Returns JSON with table schema, partition spec, location, etc.

// Check existence
boolean exists = catalog.tableExists("demo_db.demo_table");

// Clean up
catalog.close();

Related Pages

Implements Principle

• Principle:Risingwavelabs_Risingwave_Iceberg_Catalog_Operations

Requires Environment

• Environment:Risingwavelabs_Risingwave_Java_Connector_Environment