List required fields, optional sections, formatting rules and target readers. The scope is a standalone Java tool adjacent to AEM engineering; no particular rendering library or client workflow is invented.
CASE 10 / JAVA TOOLING / DOCUMENT GENERATION
Java PDF and RTF Generation: Templates, Format Boundaries and Validation.
Producing PDF and RTF from the same input requires more than changing a file extension. This representative Java tool design separates input mapping from format-specific rendering and makes document correctness testable without claiming an AEM Forms implementation.
Representative engineering design, not a verified client delivery record. Implementation steps and validation checks describe the proposed approach; no measured results are claimed.
01 / OVERVIEW
Define the document contract before choosing a library
02 / THE ENGINEERING PROBLEM
A document that opens can still be incorrect
Missing values, broken characters and unexpected pagination can pass a simple file-exists check. Each output format needs checks tied to the document’s actual purpose.
03 / ARCHITECTURE
Use a shared document model with format adapters
Validate input into a typed document model, apply template rules and hand the result to separate PDF and RTF renderers. Keep format-specific escaping, layout and output handling outside the business input mapping.
04 / IMPLEMENTATION
Make rendering deterministic at the input boundary
Normalize input and explicitly handle optional values before rendering. Define ownership of streams and temporary files, bound resource use and return errors that distinguish invalid input from renderer failure.
- Test long text, empty sections and non-ASCII characters.
- Specify template version and required font assumptions.
- Avoid logging sensitive document contents during failure analysis.
05 / TECHNICAL DECISIONS
Share semantic content, not identical layout code
Both formats can consume the same document model without promising identical pagination. Keep the shared contract semantic and let each adapter handle its format’s capabilities.
06 / TRADEOFFS
Portability and visual fidelity need different tests
A generic document model reduces coupling but cannot erase differences between viewers and rendering engines. Decide which visual properties matter and verify them in the supported readers.
07 / VALIDATION
Check content, structure and representative rendering
Byte-for-byte comparison alone may be brittle if generated metadata varies. Test stable properties and inspect representative output in addition to parser-level checks.
- Assert expected text and section presence for both formats.
- Exercise invalid input, renderer errors and resource cleanup.
- Review page breaks, special characters and long tables using actual fixtures.
08 / LESSONS LEARNED
Keep document generation outside content retrieval
A separate renderer makes it possible to add an AEM content adapter later. That adapter is an extension point, not a claim that this tool was integrated with an AEM platform.
NEXT STEPS
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