cobol-migration-analyzer

name cobol-migration-analyzer description Analyzes legacy COBOL programs and JCL jobs to assist with migration to modern Java applications. Extracts business logic, identifies dependencies, generates migration reports, and creates Java implementation strategies. Use when working with mainframe migration, COBOL analysis, legacy system modernization, JCL workflows, or when users mention COBOL to Java conversion, analyzing .cbl/.CBL/.cob files, working with copybooks, or planning Java service implementations from COBOL programs. metadata {"version":"1.0","category":"legacy-migration"} COBOL Migration Analyzer Analyze legacy COBOL programs and JCL scripts for migration to Java. Extract business logic, data structures, and dependencies to generate actionable migration strategies. Core Capabilities 1. COBOL Program Analysis Extract COBOL divisions (IDENTIFICATION, ENVIRONMENT, DATA, PROCEDURE), Working-Storage variables, file definitions (FD), business logic paragraphs, PERFORM statements, CALL hierarchies, embedded SQL, and error handling patterns. 2. JCL Job Analysis Parse JCL job steps, program invocations, data dependencies (DD statements), conditional logic (COND, IF/THEN/ELSE), return codes, and resource requirements. 3. Copybook Processing Extract record layouts with level numbers, REDEFINES clauses, group items, OCCURS clauses, and picture clauses. Generate Java POJOs from copybook structures. 4. Dependency Mapping Build complete dependency graphs showing CALL hierarchies, copybook usage, file dependencies, database table access, and shared utility references across the codebase. Workflow Step 1: Discover COBOL Assets Find COBOL programs, JCL jobs, and copybooks: find . -name "*.cbl" -o -name "*.CBL" -o -name "*.cob" find . -name "*.jcl" -o -name "*.JCL" find . -name "*.cpy" -o -name "*.CPY" Use scripts/analyze-dependencies.sh or scripts/analyze-dependencies.ps1 to generate dependency graph. Step 2: Extract Structure Use scripts/extract-structure.py to parse COBOL programs and extract divisions, variables, paragraphs, and dependencies in JSON format. Step 3: Generate Java Code Use scripts/generate-java-classes.py to convert copybooks to Java POJOs with appropriate data types and Bean Validation annotations. Step 4: Estimate Complexity Use scripts/estimate-complexity.py to calculate migration complexity based on LOC, external calls, file operations, SQL statements, and control flow. Step 5: Create Migration Strategy Document program overview, dependencies, data structures, business logic patterns, proposed Java design, migration estimate, and action items. Quick Reference COBOL to Java Type Mapping COBOL Picture Java Type Notes PIC 9(n) int , long , BigInteger Unsigned numeric PIC S9(n) int , long , BigInteger Signed numeric PIC 9(n)V9(m) BigDecimal Unsigned decimal PIC S9(n)V9(m) BigDecimal Signed decimal PIC S9(n)V9(m) COMP-3 BigDecimal Packed decimal - critical precision! PIC S9(n) COMP / BINARY int , long Binary storage PIC S9(n) COMP-1 float Single precision (avoid for financial) PIC S9(n) COMP-2 double Double precision (avoid for financial) PIC X(n) String Alphanumeric/character PIC A(n) String Alphabetic only PIC N(n) String National/Unicode OCCURS n List<T> or T[] Fixed arrays/tables OCCURS n DEPENDING ON List<T> Variable-length arrays 88 level enum or constants Condition names INDEX int Table index (1-based in COBOL) Common Pattern Conversions File I/O : READ...AT END → BufferedReader with try-with-resources or NIO streams File updates : REWRITE → Update operations in DB or file systems Table lookup : SEARCH → Linear search with streams Binary search : SEARCH ALL → Collections.binarySearch() or stream().filter().findFirst() String operations : STRING/UNSTRING → StringBuilder or String.split() Inspection : INSPECT → String.replace() , replaceAll() , or regex CALL statements : → Method calls or service invocations EVALUATE : → switch statement (Java 14+ with enhanced switch) Date arithmetic : FUNCTION INTEGER-OF-DATE → LocalDate operations ACCEPT DATE/TIME : → LocalDate.now() , LocalTime.now() Condition names (Level 88) : → enum or typed constants Computed GO TO : → Strategy pattern or switch statement REDEFINES : → Union types, ByteBuffer views, or separate accessor classes COPY statements : → Package imports or shared entity classes Example: Copybook to Java POJO COBOL Copybook: 01 EMPLOYEE-RECORD. 05 EMP-ID PIC 9(6). 05 EMP-NAME PIC X(30). 05 EMP-SALARY PIC S9(7)V99 COMP-3. Generated Java: public class EmployeeRecord { private int empId; private String empName; private BigDecimal empSalary; // getters/setters } Migration Considerations Critical Patterns: ALWAYS use BigDecimal for COMP-3 and numeric with decimals (never float/double) Preserve precision : Use BigDecimal with exact scale for financial calculations 1-based indexing : Document that COBOL arrays start at 1, Java at 0 Implicit conversions : Make COBOL's automatic numeric↔string conversions explicit REDEFINES : Model as union type, ByteBuffer overlay, or separate view classes Computed GO TO : Refactor to strategy pattern or switch statement ALTER statement : Refactor to structured control flow (if/while/switch) PERFORM THRU : Map to single method containing full paragraph range BY REFERENCE vs BY CONTENT : Document parameter passing semantics Test rigorously : Validate with production data samples, especially for COMP-3 Output Requirements: Program overview and type classification Complete dependency graph (CALL tree, copybooks, files, DB tables) Data structure mapping (copybooks → Java classes) Business logic summary (key paragraphs → methods) Proposed Java architecture (services, repositories, entities) Migration effort estimate (complexity score, LOC, risk factors) Prioritized action items Advanced Topics For detailed conversion rules and patterns, see: pseudocode-cobol-rules.md - Comprehensive COBOL to pseudocode conversion rules including data types, statements, file operations, string operations, table operations, program control, translation patterns, and common gotchas pseudocode-common-rules.md - Common pseudocode syntax and conventions applicable to all languages transaction-handling.md - Transaction management and rollback strategies for CICS/IMS to Java messaging-integration.md - Message queue and async patterns (MQ, CICS queues to JMS/Kafka) performance-patterns.md - Batch processing optimization and memory management testing-strategy.md - Comprehensive testing including unit, integration, parallel validation, and data-driven testing Tools and Scripts All scripts support cross-platform execution (Windows PowerShell, bash): analyze-dependencies.sh/ps1 - Generate dependency graph extract-structure.py - Parse COBOL structure to JSON generate-java-classes.py - Convert copybooks to Java POJOs estimate-complexity.py - Calculate migration complexity score Scripts use standard libraries only and output JSON for easy integration with CI/CD pipelines.