[adityamparikh]

Stacked on #269 (./gradlew build runs buildSrc's tests) and #266 (google-java-format): the first two commits here are those PRs, and only the top commit (fix: remove unreachable null checks and declare real nullability) is new.

What

Fixes IntelliJ's nullness warnings across src/main and src/test, the conditions it reports as always true or always false, and the dead code next to them. Every warning was one of two things, and each kind gets its own fix:

• A null check on an input that can't be null: the check is removed.
• A type claiming non-null for a value that can be null: the type is corrected and the check stays.

Null checks removed

Required @McpToolParam/@McpArg parameters no longer null-check. MCP SDK 2.0 validates tool arguments against the input schema before dispatch. CompleteRequest and CompleteArgument also reject a null argument or value in their constructors. The blank and empty checks stay.

Affected:

• AliasService: create and delete alias
• CollectionService: createCollection, completeCollection, extractCollectionName, isHandlerStatsEmpty
• SchemaService: collection and list validation
• IndexingService: Markdown documents, prompt format
• JsonDocumentCreator and IndexingDocumentCreator
• SearchService: sort clauses

Types corrected; checks kept

Where	Why it can be null
purpose, sample, sampleDocument prompt arguments; PromptText.optionalCodeBlock(content)	optional @McpArgs
CollectionUtils.getLong/getFloat/getInteger now take NamedList<?>; extractSingleCacheInfo, fetchMetrics	NamedList.get returns null for a missing key
JsonResponseParser containers are @Nullable Object	JSON null values
MarkdownDocumentCreator.addValue(@Nullable Object value)	YAML front matter such as key: with no value
SearchResponse.maxScore, QueryStats.maxScore	null when scores weren't requested
SortClause.order	optional; see below

For NamedList, declaring NamedList<Object> told IntelliJ that values can't be null. Removing the check, as the quick-fix suggests, would turn a missing key into an NPE. In getFloat, the next line is Float.parseFloat(value.toString()). In extractSingleCacheInfo, a cache entry is always absent on Solr 10.

SortClause.order: the search tool tells clients order is optional and defaults to asc. The generated input schema listed it as required, though, so the SDK rejected a sort clause without an order before the default was ever applied. With @Nullable, only field is required:

before: sortClauses.items.required = ["field", "order"]
after:  sortClauses.items.required = ["field"]

Tests

• Removed: the 10 tests that only passed null to parameters that are now required.
• Kept on purpose: two tests pass null to pin a contract: the SDK rejecting a null completion value, and Spring's binder passing null when solr.url is absent. They keep the null and suppress DataFlowIssue on that method only.
• Real nullability: captured system properties are @Nullable, since System.getProperty returns null when unset. Test lists built with a null value are NamedList<@Nullable Object>.
• No more unboxing nullable counters: the cache and handler assertions use AssertJ isPositive(), which also fails clearly on null. Float comparisons use isCloseTo.
• Assertions that couldn't fail now test something:
  • required() || !required() now checks that collection is required and the other search parameters are optional.
  • size() >= 0 now checks that the _default configset has dynamic fields.
  • The span timestamps check now requires every span to have started and to have ended no earlier than it started. SimpleSpan never returns null timestamps.
• Lifecycle fields: McpClientIntegrationTestBase uses @AutoClose instead of a manual null-guarded afterAll. DockerImageHttpIntegrationTest builds its HttpClient inline and reads the base URL from the container.
• Dead code removed: unused fields and mocks, unused throws Exception clauses (37, two of them in HttpSecurityConfiguration), redundant casts, an empty else, and two Javadoc links to test classes that aren't accessible from where they're used.

Not changed

• @McpArg(required = false): IntelliJ calls these redundant defaults. The repo writes required explicitly on every parameter, because @McpToolParam and @McpArg have opposite defaults.
• Other warning types are separate changes:
  • deprecated-API migrations: Jackson 3 text accessors, MCP request constructors, Testcontainers SolrContainer
  • record-component Javadoc (DanglingJavadoc)
  • package-private DTOs returned from public methods
  • unused public test helpers
  • style hints: method references, getFirst(), expression lambdas

Verification

• ./gradlew build passes, with all 455 tests run, none skipped or failed. That's style: format Java sources with google-java-format #266's 465 minus the 10 removed null tests. buildSrc's 12 tests run in the same build via build: run buildSrc's tests as part of the build #269. NullAway, which fails the build on src/main, accepts every new @Nullable.
• IntelliJ's ConstantValue inspection run on all 37 changed files reports nothing. The same run flags the original CollectionUtils.
• DataFlowIssue and NullableProblems reproduce every original warning on the unedited files. On the changed files, the only hits are calls into signatures this PR changes, checked against their old declarations.

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

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

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