What happened?

/take-issue

Bug Description

The JavaJarProvider.available() method in apache_beam/yaml/yaml_provider.py uses the Unix-specific which command to check for Java availability, which causes a FileNotFoundError on Windows systems.

Environment

• OS: Windows 10/11
• Python version: 3.12.10
• Apache Beam version: Latest (from main branch)
• Error location: apache_beam/yaml/yaml_provider.py:388

Error Details

FileNotFoundError: [WinError 2] 系统找不到指定的文件。
  File "apache_beam\yaml\yaml_provider.py", line 388, in available
    trial = subprocess.run(['which', 'java'], capture_output=True)

Root Cause

The which command is Unix/Linux specific and doesn't exist on Windows. Windows uses the where command for similar functionality.

Current Code

def available(self):
  # pylint: disable=subprocess-run-check
  trial = subprocess.run(['which', 'java'], capture_output=True)
  if trial.returncode == 0:
    return True
  else:
    # ... error handling

Expected Behavior

The YAML provider should work correctly on all supported platforms including Windows.

Proposed Solution

Use platform-specific commands:

• Windows: where java
• Unix/Linux: which java
• Fallback: shutil.which('java') for cross-platform compatibility

Impact

This affects all Windows users trying to use Apache Beam's YAML functionality, preventing them from using this feature entirely.

Workaround

Currently, users need to either:

1. Install a Unix-like environment (WSL, Git Bash, etc.)
2. Create a custom which.bat script
3. Apply manual patches to the source code

Additional Context

This is a cross-platform compatibility issue that should be straightforward to fix with platform detection.

Labels

/add-labels bug,P2,windows,yaml,cross-platform

Issue Priority

Priority: 2 (default / most bugs should be filed as P2)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
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