http-client-java, support nested pageItems, nextLink, continuationToken

[weidongxu-microsoft]

test would be in #6477
(PS: we may need to skip this tsp in Azure)

impl code looks like this

    @ServiceMethod(returns = ReturnType.SINGLE)
    public PagedResponse<Pet> nestedLinkNextSinglePage(String nextLink) {
        final String accept = "application/json";
        Response<NestedLinkResponse> res
            = service.nestedLinkNext(nextLink, this.client.getEndpoint(), accept, RequestContext.none());
        return new PagedResponse<>(res.getRequest(), res.getStatusCode(), res.getHeaders(),
            res.getValue().getNestedItems().getPets(), null,
            res.getValue().getNestedNext() != null && res.getValue().getNestedNext().getNext() != null
                ? res.getValue().getNestedNext().getNext()
                : null,
            null, null, null);
    }

pageItems should always be there so there is no null check <- this could be wrong but worry about it later

[github-actions]

No changes needing a change description found.

[Copilot]

Pull Request Overview

This PR refactors the pagination support in the HTTP client Java package to enable nested pageItems, nextLink, and continuationToken handling. Key changes include:

• Refactoring ClientCoreClientMethodTemplate to use helper methods for nested property extraction with null checks.
• Updating MethodPageDetails and PagingMetadata to use lists (instead of single values) for pageItems and nextLink.
• Adjusting test implementations and code model builder to align with the new nested paging model.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
ClientCoreClientMethodTemplate.java	Refactored pagination logic to use helper methods (valueLine, nextLinkLine, nestedReferenceLineWithNullCheck) for nested paging properties.
MethodPageDetails.java	Changed to use List for pageItems and nextLink, accessing the first element for property names.
PagingMetadata.java	Updated to support list-based extraction of page items and next link properties.
ClientMethodsReturnDescription.java	Adjusted element type mapping to integrate the new paging properties.
XmsPageable.java	Added getters/setters for nested pageItems and nextLink properties.
ServerDrivenPaginationsImpl.java and ServerDrivenPaginationContinuationTokensImpl.java	Updated PagedResponse construction to include redundant null checks for next tokens using the new paging fields.
operation-utils.ts and code-model-builder.ts	Incorporated new logic for handling nested paging properties in response schemas.

[azure-sdk]

You can try these changes here

🛝 Playground	🌐 Website	🛝 VSCode Extension

[haolingdong-msft]

Could you please show what does output code-model.yaml look like?