[FEATURE] Java client generation

# Add Support for Java Client Generation in Industry Toolkit

**Description:**
The Industry Toolkit will include support for generating client SDKs in Java based on API definitions. This will enable developers to generate Java clients for interacting with APIs built using the toolkit.

### Feature Requirements:
- Generate Java client SDKs from API definitions.
- Ensure compatibility with modern Java versions and frameworks.
- Provide comprehensive documentation and code comments in the generated clients.
- Include examples on how to use the generated Java SDKs in applications.
- Write tests to validate the correctness of the generated SDKs.

### Acceptance Criteria:
- [ ] Java client generation feature is implemented.
- [ ] Generated SDKs include documentation and are tested for correctness.
- [ ] README and documentation are updated with instructions on generating and using Java clients.

**Additional Context:**
This feature will enable seamless integration of APIs into Java-based applications, streamlining development for Java developers.

The issue names no files, tests, or generator entry point, so first locate the existing API-definition and client-generation workflow in the repository. Define the Java generation approach and verify it against the stated acceptance criteria: generated SDK documentation, correctness tests, usage examples, and updated README or documentation.

Written by the indexing model from the issue text.