Skip to content

Typed WQL results: map CIM values to Java objects instead of strings #194

Description

@bertysentry

Follow-up to #189 (PR #193), where WMI array properties were fixed to come back as a single string joined with | (configurable with WinRMClient.Builder.arraySeparator(String)).

Problem

Every WQL value is exposed as a String, whatever its CIM type. Consumers parse numbers, booleans, dates and now |-joined arrays themselves:

  • WqlRow.get(String) is declared Object but always returns a String.
  • An array property is a joined string: a single-element array is indistinguishable from a scalar, and an element that contains the separator is ambiguous.
  • NULL is an empty string, indistinguishable from an empty string value.
  • CIM datetimes arrive in the WS-Management form (<cim:Datetime>2024-05-01T12:34:56.789Z</cim:Datetime> for CIM_DATETIME values, or an interval), which nobody wants to parse by hand.

Proposal

A typed result variant where the row values are native Java objects, alongside the existing string-based API (which stays the default, and the only one for the legacy WinRMWqlExecutor.getRows() / List<List<String>>).

Suggested shape, to be refined:

  • Opt in per query, e.g. client.wql(query).typed().execute(), or a WqlRow.typed(String) / WqlRow.list(String) accessor family; the legacy List<Map<String, Object>> of WindowsRemoteExecutor.executeWql could also carry typed values under an opt-in flag, so WinRMWqlExecutor keeps its strings.
  • Mapping from the type information WS-Management gives us. The instance XML carries no xsi:type; the CIM type must come from the class schema (a WSMan Get of the class definition, winrm get wmi/...?__CLASS, or the p: XML schema), or from the value form (<cim:Datetime> wrapper, xsi:nil, repeated elements).

Suggested mapping:

CIM type Java
string, char16 String
boolean Boolean
sint8/sint16/sint32/sint64, uint8/uint16/uint32 Integer / Long (uint64 → BigInteger or Long)
real32/real64 Float / Double
datetime java.time.Instant / OffsetDateTime for timestamps, Duration for intervals
reference String (the object path)
embedded object nested WqlRow
array of any of the above List<T>
NULL (xsi:nil="true") null

Open questions

  • Where the CIM type information comes from without an extra round trip per query (cache the class schema per client and class?).
  • Whether the WS-Management datetime encoding is consistent across Windows versions (2008 R2 through 2022 are available as test hosts).
  • Whether the CLI should emit JSON arrays/numbers/booleans/null when typed values are available (today it emits strings only).

Not in scope

The string API stays as it is: the | join and the empty-string NULL are documented behavior since 2.3.00.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    enhancementNew feature or request

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions