Refactor StatementServiceImpl and CallResourceAction; introduce ResultSetHelper and FetchNextRowsAction

[felipestanzani]

closes #222

Summary

Refactors the gRPC statement and resource handling to reduce duplication, centralize shared logic, and improve maintainability. Net change: -420 lines, +269 lines across 4 files.

Changes

New components

• ResultSetHelper (org.openjproxy.grpc.server.action.session)

  • Extracted result set handling from StatementServiceImpl into a reusable helper.
  • Handles row iteration, type conversion (LOB, CLOB, BLOB, dates, timestamps), metadata collection for DB2, and streaming via ResultSetWrapper.
  • Exposes handleResultSet() and updateSessionActivity() for use by other actions.

• FetchNextRowsAction (org.openjproxy.grpc.server.action.transaction)

  • New action for fetching subsequent rows from result sets.
  • Encapsulates session activity updates, cluster health processing, and result set handling.
  • Replaces the inline logic previously in StatementServiceImpl.fetchNextRows().

Refactored components

• StatementServiceImpl

  • Removed ~250 lines of duplicated logic.
  • Uses SessionConnectionHelper.sessionConnection() instead of its own sessionConnection().
  • Uses ResultSetHelper.handleResultSet() instead of its own handleResultSet().
  • Delegates fetchNextRows to FetchNextRowsAction.
  • Moved XADataSource, XATransactionRegistry, unpooled connection details, and cluster health tracker into ActionContext.
  • Cleaned up imports and simplified null checks.

• CallResourceAction

  • Removed ~95 lines of duplicated sessionConnection() logic.
  • Uses SessionConnectionHelper.sessionConnection() for connection/session handling.
  • Uses pattern matching for instanceof (e.g. CallableStatement cs, ResultSet rs).
  • Simplified null checks and removed redundant conditionals.

Benefits

• DRY: Shared session connection and result set logic moved into helpers.
• Single responsibility: FetchNextRowsAction owns fetch-next-rows behavior.
• Testability: ResultSetHelper and FetchNextRowsAction can be tested in isolation.
• Consistency: Session connection and error handling aligned across statement and resource flows.

Testing

• Existing tests pass
• Manual verification of query execution and result set streaming
• Manual verification of fetch-next-rows behavior
• Manual verification of resource operations (statements, prepared statements, callable statements)

[sonarqubecloud]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud