Convert COBOL merge_sort_test.cbl to Java - MBA-18

[devin-ai-integration]

Convert COBOL merge_sort_test.cbl to Java - MBA-18

Summary

This PR converts the COBOL program merge_sort/merge_sort_test.cbl to a functionally equivalent Java program MergeSortExample.java for ticket MBA-18. The conversion preserves the exact three-step workflow:

1. Create test data: Generates two test files with hardcoded customer records
2. Merge and sort: Combines files and sorts by ascending customer ID
3. Sort by contract: Re-sorts merged data by descending contract ID

Key implementation details:

• CustomerRecord class with 5-digit customer ID, 50-char names, 5-digit contract ID, 25-char comment
• Fixed-width string formatting to match COBOL's PIC clauses
• Java Collections framework for sorting operations
• Same file names and console output behavior as original COBOL

Review & Testing Checklist for Human

• Verify test data accuracy: Cross-reference the hardcoded customer records in createTestData() with the original COBOL source (lines 185-334) to ensure no transcription errors
• Compare output formatting: Run both programs and verify the fixed-width console output matches exactly - pay special attention to field widths and padding
• Test file operations: Verify all 5 output files are created correctly (test-file-1.txt, test-file-2.txt, work-temp.txt, merge-output.txt, sorted-contract-id.txt) with proper content
• Validate sorting behavior: Confirm merge sorts by ascending customer ID (1,3,5,10,24,25,30,50,75,85,999) and final sort by descending contract ID (12323→247)

Recommended test plan: If possible, compile and run the original COBOL program and compare its console output and generated files with the Java version to verify functional equivalence.

---

Diagram

%%{ init : { "theme" : "default" }}%%
graph TD
    COBOL["merge_sort_test.cbl<br/>(Original COBOL)"]:::context
    Java["MergeSortExample.java<br/>(New Java conversion)"]:::major-edit
    
    TestFile1["test-file-1.txt<br/>(6 customer records)"]:::context
    TestFile2["test-file-2.txt<br/>(5 customer records)"]:::context
    MergeOutput["merge-output.txt<br/>(11 records, sorted by customer ID)"]:::context
    SortedOutput["sorted-contract-id.txt<br/>(11 records, sorted by contract ID desc)"]:::context
    
    COBOL -->|"converted to"| Java
    Java -->|"creates"| TestFile1
    Java -->|"creates"| TestFile2
    Java -->|"merges & sorts"| MergeOutput
    Java -->|"sorts by contract ID"| SortedOutput
    
    subgraph Legend
        L1[Major Edit]:::major-edit
        L2[Minor Edit]:::minor-edit
        L3[Context/No Edit]:::context
    end

classDef major-edit fill:#90EE90
classDef minor-edit fill:#87CEEB
classDef context fill:#FFFFFF

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Notes

• Link to Devin run: https://app.devin.ai/sessions/a940d75d0ac44f9b87c72fc8027293cd
• Requested by: Samir Chaudhry (@schaudhry123)
• Ticket: MBA-18
• Critical risk: Manual transcription of test data from COBOL - recommend careful verification of customer records, contract IDs, and comments
• Testing note: Java program successfully compiles and runs, producing expected console output and file structure, but direct comparison with COBOL output would provide highest confidence

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