feat(java,info): support multi-property in yaml

[yangxk1]

Reason for this PR

close #778

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 59.42029% with 28 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.60%. Comparing base (6f112c6) to head (b808b9b).
⚠️ Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
...rc/main/java/org/apache/graphar/info/EdgeInfo.java	0.00%	3 Missing and 3 partials ⚠️
...c/main/java/org/apache/graphar/info/GraphInfo.java	0.00%	3 Missing and 3 partials ⚠️
...java/org/apache/graphar/info/type/Cardinality.java	62.50%	3 Missing and 3 partials ⚠️
.../apache/graphar/info/saver/BaseGraphInfoSaver.java	28.57%	3 Missing and 2 partials ⚠️
.../java/org/apache/graphar/info/yaml/VertexYaml.java	66.66%	1 Missing and 1 partial ⚠️
...rc/main/java/org/apache/graphar/info/Property.java	90.00%	0 Missing and 1 partial ⚠️
.../main/java/org/apache/graphar/info/VertexInfo.java	66.66%	0 Missing and 1 partial ⚠️
...ava/org/apache/graphar/info/yaml/PropertyYaml.java	90.90%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##               main     #780    +/-   ##
==========================================
  Coverage     76.59%   76.60%            
- Complexity      560      585    +25     
==========================================
  Files            83       84     +1     
  Lines          8679     8788   +109     
  Branches       1006     1018    +12     
==========================================
+ Hits           6648     6732    +84     
- Misses         1813     1826    +13     
- Partials        218      230    +12     

Flag	Coverage Δ
java-info	82.20% <59.42%> (-0.54%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[yangxk1]

Hey @Thespica, please help me review.

[Copilot]

Pull request overview

This PR adds support for multi-valued properties (LIST and SET cardinality) in GraphAr's Java implementation, enabling properties to hold multiple values instead of just single values. The implementation introduces a new Cardinality enum and integrates it throughout the info layer for YAML serialization/deserialization.

Key Changes

• Introduces Cardinality enum (SINGLE, LIST, SET) to distinguish single-valued from multi-valued properties
• Updates Property, PropertyYaml, and related info classes to support cardinality metadata
• Adds validation rules: edges only support SINGLE cardinality, and CSV files don't support multi-cardinality properties
• Enhances BaseGraphInfoSaver to auto-generate filenames when saving to directories

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 16 comments.

Show a summary per file

File	Description
maven-projects/info/src/main/java/org/apache/graphar/info/type/Cardinality.java	New enum defining SINGLE, LIST, and SET cardinality types with string conversion methods
maven-projects/info/src/main/java/org/apache/graphar/info/Property.java	Adds cardinality field and constructors to support multi-valued properties
maven-projects/info/src/main/java/org/apache/graphar/info/yaml/PropertyYaml.java	Adds cardinality field for YAML serialization, with special handling to omit SINGLE from output
maven-projects/info/src/main/java/org/apache/graphar/info/PropertyGroup.java	Adds getCardinality() method and validation to reject multi-cardinality in CSV files
maven-projects/info/src/main/java/org/apache/graphar/info/VertexInfo.java	Exposes getCardinality() method and adds validation calls before dumping
maven-projects/info/src/main/java/org/apache/graphar/info/EdgeInfo.java	Adds validation to reject multi-cardinality properties in edges and validation calls before dumping
maven-projects/info/src/main/java/org/apache/graphar/info/GraphInfo.java	Adds validation calls before dumping YAML
maven-projects/info/src/main/java/org/apache/graphar/info/yaml/VertexYaml.java	Adds unused labels field (unrelated to multi-property feature)
maven-projects/info/src/main/java/org/apache/graphar/info/saver/BaseGraphInfoSaver.java	Adds auto-filename generation when URIs are directories
maven-projects/info/src/test/java/org/apache/graphar/info/MultiPropertyTest.java	Comprehensive test suite for cardinality functionality including YAML round-trip and validation
maven-projects/info/src/test/java/org/apache/graphar/info/TestDataFactory.java	Adds factory method for creating properties with cardinality
maven-projects/info/src/test/java/org/apache/graphar/info/TestUtil.java	Adds helper methods to access LDBC test data with multi-property support
maven-projects/info/src/test/java/org/apache/graphar/info/TestVerificationUtils.java	Adds cardinality assertion to property comparison
maven-projects/info/src/test/java/org/apache/graphar/info/GraphInfoTest.java	Adds cardinality assertions to existing property tests

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Thespica]

LGTM