Convert COBOL merge sort program to Java for MBA-18

[devin-ai-integration]

Convert COBOL merge sort program to Java for MBA-18

Summary

Converts the merge_sort_test.cbl COBOL program to functionally equivalent Java code. The Java implementation:

• Implements CustomerRecord class with exact field structure (5-digit IDs, 50/50-char names, 25-char comment)
• Replicates all three procedures: createTestData(), mergeAndDisplayFiles(), sortAndDisplayFile()
• Uses Java Collections framework with custom Comparators to replicate COBOL's MERGE and SORT behavior
• Maintains fixed-width file formatting (135 characters per record) to match line sequential organization
• Preserves identical console output and file names (test-file-1.txt, test-file-2.txt, merge-output.txt, sorted-contract-id.txt)

The program creates two test data files with hardcoded customer records, merges them sorted by customer ID ascending, then sorts the merged file by contract ID descending, displaying results at each step.

Review & Testing Checklist for Human (5 items)

• Run both COBOL and Java programs and verify the output files are identical - Compare merge-output.txt and sorted-contract-id.txt content byte-for-byte
• Verify console output matches exactly - The display statements should show identical formatted records in the same order
• Validate fixed-width formatting - Each record should be exactly 135 characters (5+50+50+5+25) with proper padding
• Cross-check all 11 hardcoded test data values against the COBOL source (lines 185-333) - Any transcription errors would cause output differences
• Test error scenarios - Try running with read-only directories or full disk to ensure error handling behaves reasonably

Notes

• Successfully compiled and ran locally, generating all expected output files
• Used standard Java idioms (Collections.sort, try-with-resources) while preserving COBOL behavior
• Link to Devin run: https://app.devin.ai/sessions/19450015cbac498495a21f612fe7d9d8
• Requested by: @parkerduff

Risk Level: 🟡 Medium - Language translation with hardcoded data requires careful validation of functional equivalence

[devin-ai-integration]

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