COG-GTM · devin-ai-integration · Mar 17, 2026 · Mar 27, 2026 · Mar 27, 2026
diff --git a/cobol-migration/.gitignore b/cobol-migration/.gitignore
@@ -0,0 +1,16 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IDE ###
+.classpath
+.project
+.settings/
+.idea/
+*.iml
+*.iws
+*.ipr
+
+### OS ###
+.DS_Store
diff --git a/cobol-migration/README.md b/cobol-migration/README.md
@@ -0,0 +1,151 @@
+# COBOL to Spring Boot Migration
+
+This Spring Boot 3.x application replaces the GnuCOBOL programs in the [COBOL-Examples](../) repository with modern Java 17+ equivalents. The original COBOL files are retained in their directories for reference.
+
+## Quick Start
+
+### Prerequisites
+- Java 17+
+- Maven 3.8+
+- PostgreSQL 12+ (for database features)
+
+### Build & Test
+```bash
+cd cobol-migration
+mvn clean install
+```
+
+### Run
+```bash
+mvn spring-boot:run
+```
+The application starts on `http://localhost:8080`.
+
+### Database Setup
+1. Create a PostgreSQL database named `cobol_db_example`
+2. Flyway migrations run automatically on startup (creates the `accounts` table and seeds test data)
+3. Configure connection in `src/main/resources/application.properties` if defaults differ
+
+## API Endpoints
+
+| Method | Endpoint | Replaces | Description |
+|--------|----------|----------|-------------|
+| GET | `/api/accounts` | sql_example.cbl menu option 1 | List all accounts |
+| GET | `/api/accounts/disabled` | sql_example.cbl menu option 2 | List disabled accounts |
+| GET | `/api/accounts/search?q={term}` | sql_example.cbl menu option 3 | Search accounts (LIKE wildcard) |
+| GET | `/api/serialize/json` | json_generate.cbl | JSON serialization demo |
+| GET | `/api/serialize/xml` | xml_generate.cbl | XML serialization demo |
+| POST | `/api/customers/merge-sort` | merge_sort_test.cbl merge | Merge and sort two customer lists |
+| GET | `/api/customers/demo` | merge_sort_test.cbl full flow | Run complete merge/sort demo |
+| POST | `/api/reports/student` | report_test.cbl | Generate formatted student report |
+
+## Migration Mapping
+
+### COBOL File to Java Equivalent
+
+| COBOL Source | Java Equivalent | Notes |
+|---|---|---|
+| `sql/sql_example.cbl` | `AccountController`, `AccountService`, `AccountRepository` | Terminal menu replaced with REST API; embedded SQL replaced with Spring Data JPA |
+| `sql/create_test_db.sql` | `V1__create_accounts.sql`, `V2__seed_data.sql` | Flyway migration files; `\c` command removed |
+| `json_generate/json_generate.cbl` | `SerializationController.getJson()`, `SerializableRecord` | `JSON GENERATE` replaced with Jackson JSON |
+| `xml_generate/xml_generate.cbl` | `SerializationController.getXml()`, `SerializableRecord` | `XML GENERATE` replaced with Jackson XML; attribute/suppress behavior preserved |
+| `merge_sort/merge_sort_test.cbl` | `CustomerFileController`, `CustomerFileService`, `CustomerFileRecord` | File-based SORT/MERGE replaced with `Comparator` and in-memory lists |
+| `report_writer/report_test.cbl` | `ReportController`, `ReportService`, `StudentRecord` | COBOL Report Writer replaced with formatted String output |
+| `redifines/redefines.cbl` | `Customer` (abstract), `PersonCustomer`, `CorpCustomer` | `REDEFINES` pattern modeled with Java inheritance and polymorphism |
+| `is_numeric/is_numeric.cbl` | `ValidationService.isNumeric()` | Three COBOL approaches (plain, zero-fill, trim) replicated |
+| `numval_test/numval_test.cbl` | `ValidationService.parseNumericValue()` | `FUNCTION NUMVAL` replaced with `NumberUtils.isCreatable()` |
+| `trim/trim.cbl` | `StringUtilService.trimVariants()` | `FUNCTION TRIM` (full/leading/trailing) mapped to `String.strip*()` |
+| `unstring/unstring.cbl` | `StringUtilService.splitByDelimiter()`, `splitByMultipleDelimiters()`, `splitFormattedNumber()` | `UNSTRING` with `DELIMITER IN`, `COUNT IN`, `TALLYING IN` |
+| `search/search.cbl` | `SearchDemoService` | `SEARCH ALL` (binary) -> `Collections.binarySearch()`; `SEARCH` (sequential) -> `Stream.filter()` |
+| `sub_program/main_app.cbl`, `sub.cbl` | Service layer pattern (documented in `AppConfig.java`) | `CALL BY CONTENT` = immutable params; `CALL BY REFERENCE` = mutable objects |
+
+### Terminal UI Programs (Dropped or Replaced)
+
+| COBOL Source | Disposition | Notes |
+|---|---|---|
+| `accept/accept.cbl` | Replaced | Input validation concepts applied in controllers |
+| `accept/accept_from.cbl` | Replaced | Environment vars -> `@Value`; dates -> `java.time`; args -> `ApplicationArguments` |
+| `screen_size/get_screen_size.cbl` | Dropped | Terminal dimensions not applicable to web |
+| `display_test/display-test.cbl` | Dropped | Positioned display with colors not applicable |
+| `mouse/mouse_example.cbl` | Dropped | Mouse paint program not applicable |
+| `display_timing/display_timing.cbl` | Dropped | Screen write benchmarking not applicable |
+| `read_command_args/` | Replaced | Command-line args -> Spring Boot `ApplicationArguments` |
+| `comp_test/comp_test.cbl` | Dropped | Java handles numeric types natively |
+
+## Behavioral Differences
+
+| Aspect | COBOL | Java (Spring Boot) |
+|---|---|---|
+| **String handling** | Fixed-width `PIC X(n)` fields padded with spaces | Dynamic-length `String`; no implicit padding |
+| **Numeric types** | `PIC 9(n)`, `COMP-2`, `COMP-5` with explicit sizes | `int`, `long`, `double`; automatic type promotion |
+| **Null handling** | No null concept; fields always have default values | Null is possible; use validation annotations |
+| **Database access** | Embedded SQL with ODBC precompiler (esqlOC) | Spring Data JPA with HQL/JPQL queries |
+| **File I/O** | `SELECT ... ASSIGN TO`, `READ`, `WRITE` with FD | In-memory lists; file I/O via `java.nio` if needed |
+| **Memory layout** | `REDEFINES` shares memory between fields | Inheritance/polymorphism; no shared memory |
+| **Search** | `SEARCH ALL` (binary) requires sorted indexed table | `Collections.binarySearch()` requires sorted list |
+| **Sorting** | `SORT`/`MERGE` with sort work file (SD) | `List.sort()` with `Comparator` |
+| **Report generation** | Report Writer (RD, PAGE LIMIT, GENERATE) | String formatting with pagination logic |
+| **Subprograms** | `CALL BY CONTENT` / `CALL BY REFERENCE` | Method params (immutable vs mutable objects) |
+| **Terminal I/O** | `ACCEPT`/`DISPLAY` with screen coordinates | REST API with JSON request/response |
+
+## Project Structure
+
+```
+cobol-migration/
+  pom.xml
+  src/main/java/com/example/cobolmigration/
+    CobolMigrationApplication.java
+    config/
+      AppConfig.java
+    controller/
+      AccountController.java
+      CustomerFileController.java
+      ReportController.java
+      SerializationController.java
+    model/
+      Account.java               (JPA entity)
+      Customer.java              (abstract base - REDEFINES)
+      PersonCustomer.java        (extends Customer)
+      CorpCustomer.java          (extends Customer)
+      CustomerFileRecord.java    (file-based model)
+      StudentRecord.java         (report model)
+      SerializableRecord.java    (JSON/XML model)
+    repository/
+      AccountRepository.java
+    service/
+      AccountService.java
+      CustomerFileService.java
+      ReportService.java
+      SearchDemoService.java
+      SerializationService.java
+      StringUtilService.java
+      ValidationService.java
+  src/main/resources/
+    application.properties
+    db/migration/
+      V1__create_accounts.sql
+      V2__seed_data.sql
+  src/test/java/com/example/cobolmigration/
+    controller/
+      AccountControllerTest.java
+    service/
+      AccountServiceTest.java
+      CustomerFileServiceTest.java
+      ReportServiceTest.java
+      SearchDemoServiceTest.java
+      SerializationServiceTest.java
+      StringUtilServiceTest.java
+      ValidationServiceTest.java
+```
+
+## Technology Stack
+
+- **Java 17** — minimum version
+- **Spring Boot 3.2** — web framework
+- **Spring Data JPA** — database access (replaces embedded SQL/ODBC)
+- **PostgreSQL** — database (same as COBOL original)
+- **Flyway** — database migrations
+- **Jackson** — JSON/XML serialization (replaces libjson-c and libxml2)
+- **Apache Commons Lang** — utility functions
+- **JUnit 5 + Mockito** — testing
+- **Testcontainers** — PostgreSQL integration tests
diff --git a/cobol-migration/pom.xml b/cobol-migration/pom.xml
@@ -0,0 +1,112 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>3.2.5</version>
+        <relativePath/>
+    </parent>
+
+    <groupId>com.example</groupId>
+    <artifactId>cobol-migration</artifactId>
+    <version>1.0.0-SNAPSHOT</version>
+    <name>cobol-migration</name>
+    <description>Spring Boot application replacing COBOL programs from COBOL-Examples repository</description>
+
+    <properties>
+        <java.version>17</java.version>
+    </properties>
+
+    <dependencies>
+        <!-- REST API -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <!-- Database access (replaces embedded SQL) -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+
+        <!-- Input validation -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+
+        <!-- PostgreSQL driver -->
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+
+        <!-- XML serialization (replaces libxml2) -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-xml</artifactId>
+        </dependency>
+
+        <!-- JAXB API for XML annotations -->
+        <dependency>
+            <groupId>jakarta.xml.bind</groupId>
+            <artifactId>jakarta.xml.bind-api</artifactId>
+        </dependency>
+
+        <!-- Flyway for DB migrations -->
+        <dependency>
+            <groupId>org.flywaydb</groupId>
+            <artifactId>flyway-core</artifactId>
+        </dependency>
+
+        <!-- Apache Commons Lang for numeric utilities -->
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+        </dependency>
+
+        <!-- Testing -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- Testcontainers for PostgreSQL integration tests -->
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>1.19.7</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>1.19.7</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- H2 for lightweight unit tests -->
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
diff --git a/cobol-migration/src/main/java/com/example/cobolmigration/CobolMigrationApplication.java b/cobol-migration/src/main/java/com/example/cobolmigration/CobolMigrationApplication.java
@@ -0,0 +1,12 @@
+package com.example.cobolmigration;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CobolMigrationApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(CobolMigrationApplication.class, args);
+    }
+}
diff --git a/cobol-migration/src/main/java/com/example/cobolmigration/config/AppConfig.java b/cobol-migration/src/main/java/com/example/cobolmigration/config/AppConfig.java
@@ -0,0 +1,63 @@
+package com.example.cobolmigration.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.MediaType;
+import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+/**
+ * Application configuration.
+ *
+ * Subprogram Pattern (replaces sub_program/main_app.cbl and sub_program/sub.cbl):
+ * ---------------------------------------------------------------------------------
+ * The COBOL subprogram demonstrates call-by-content vs call-by-reference:
+ *
+ *   CALL "sub-app" USING BY CONTENT ws-item-1 BY CONTENT ws-item-2
+ *     -> The sub-program receives copies of the values. Changes in the sub-program
+ *        do NOT affect the caller's variables.
+ *
+ *   CALL "sub-app" USING ws-item-1 ws-item-2  (default is BY REFERENCE)
+ *     -> The sub-program can modify the caller's variables directly.
+ *
+ * In Java, this maps naturally to the service layer pattern:
+ *
+ *   - Passing immutable objects (String, Integer, records) = by-content equivalent.
+ *     The service receives a copy; the caller's value is unaffected.
+ *
+ *   - Passing mutable objects (DTOs, lists) or returning modified values = by-reference equivalent.
+ *     The service can modify the object's state, visible to the caller.
+ *
+ *   - CANCEL "sub-app" (resetting WORKING-STORAGE) has no direct equivalent in Java;
+ *     the closest pattern is creating a new service instance or resetting its state.
+ *     With Spring's default singleton scope, services maintain state across calls
+ *     (like WORKING-STORAGE), while method parameters behave like LOCAL-STORAGE
+ *     (fresh on each invocation).
+ *
+ * Terminal UI Programs — Conversion Notes:
+ * -----------------------------------------
+ * The following COBOL programs are terminal/screen-mode specific:
+ *   - accept/accept.cbl: Screen mode input. Validation concepts (upper-case conversion)
+ *     are implemented via request validation in controllers (e.g., @Valid, custom validators).
+ *   - accept/accept_from.cbl: Environment variables and dates are accessed via Spring's
+ *     @Value annotation, Environment bean, and java.time APIs.
+ *   - screen_size/get_screen_size.cbl: Terminal dimensions — not applicable to web; dropped.
+ *   - display_test/display-test.cbl: Positioned display with colors — not applicable; dropped.
+ *   - mouse/mouse_example.cbl: Mouse paint program — not applicable; dropped.
+ *   - display_timing/display_timing.cbl: Screen write benchmarking — not applicable; dropped.
+ *   - read_command_args/: Command-line args — replaced by Spring Boot's ApplicationArguments.
+ *   - comp_test/comp_test.cbl: COMP to display — Java handles numeric types natively.
+ */
+@Configuration
+public class AppConfig implements WebMvcConfigurer {
+
+    /**
+     * Configure content negotiation to default to JSON.
+     * Without this, jackson-dataformat-xml on the classpath causes Spring
+     * to prefer XML serialization for all endpoints.
+     */
+    @Override
+    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
+        configurer.defaultContentType(MediaType.APPLICATION_JSON);
+    }
+
+}