JSON to Cobol Copybook

Sometimes developers are into situations where they need to parse a JSON in Cobol. Data might come from public “bodies” or private “bodies”. It doesnt matter where it comes from, what we want is to be able to run a JSON Parse in Cobol. IBM have a parser in their mainframe Cobol compiler since version 6.2, or even earlier. Look it up in their documentation. To be able to use it you need a Cobol Copybook that reflects your JSON (pretty much 1:1). You can actually create it using AI, but again, since web-based and open AI represents a security risk we would never suggest doing so!. We have created our own JSON to Cobol Copybook converter in React.

Our React component provides an interactive tool to convert JSON data into COBOL Copybook format. Below are the key features:

1️⃣ JSON to COBOL Conversion

• Parses JSON input and generates the equivalent COBOL Copybook layout.
• Uses COBOL data types based on JSON values (e.g., PIC X(50). for strings, PIC 9(10) COMP. for integers).
• Supports nested objects and arrays, applying COBOL OCCURS for arrays.
• Outputs COBOL format in a structured and indented manner.

2️⃣ Dynamic COBOL Data Type Mapping

• Determines the COBOL data type based on JSON values:
  • String: PIC X(n). (up to 255 characters)
  • Integer: PIC 9(10) COMP.
  • Decimal (Float): PIC 9(10)V9(2) COMP.
  • Boolean: PIC X(1).
  • Date (YYYY-MM-DD format): PIC X(10).
  • Null values: PIC X(50).

3️⃣ Handles Nested Objects & Arrays

• Objects: Represented as COBOL group items (e.g., 01 JsonToCobol.)
• Arrays: Uses OCCURS n TIMES.
  • Supports arrays of objects and arrays of primitive values.
  • If an array is empty, defaults to OCCURS 4 TIMES.

4️⃣ Interactive User Interface

✅ Text Input for JSON:

• Users can enter JSON data in a textarea.

✅ Convert Button:

• Converts JSON to COBOL format.

✅ Clear Button:

• Clears both input and output fields.

✅ Copy Button:

• Selects and copies COBOL output to the clipboard.

✅ Success Popup:

• Displays a confirmation message after successful conversion.

5️⃣ Error Handling

• Invalid JSON Detection:
  • If input is not valid JSON, displays:
    "INVALID JSON. Please check your input."

6️⃣ Well-Formatted COBOL Output

• Uses proper indentation and levels for readability.
• Ensures correct field names and structure.

7️⃣ Styled UI with Responsive Design

• Uses inline CSS styling for a modern UI.
• Buttons have gradient backgrounds, shadows, and smooth transitions.

8️⃣ Clipboard Support

• Uses useRef to allow easy selection & copying of generated COBOL code.

9️⃣ Higher-Order Component (withRouter)

• Wrapped with withRouter for potential future navigation support.

Finally: If you want a demo do not hesitate in contacting us. We are sure you can create one on your own. Also we know excellent people that are happy to help you on consultancy basis. They can bring our code to you and you can have the code customized if needed. After that the code is yours.