CAMEL-24605: align FopProducer XML transformation with Camel's standard secure XML processing configuration

[oscerd]

Description

FopProducer builds a javax.xml.transform.TransformerFactory that only enables FEATURE_SECURE_PROCESSING before transforming the incoming message body.

Camel's standard XML processing utilities (for example org.apache.camel.converter.jaxp.XmlConverter) configure the factory more completely by also restricting access to external resources via XMLConstants.ACCESS_EXTERNAL_DTD and XMLConstants.ACCESS_EXTERNAL_STYLESHEET (set to an empty string).

For consistency and robustness across the codebase, this change applies the same standard configuration when FopProducer creates its TransformerFactory.

Changes

• FopProducer now sets ACCESS_EXTERNAL_DTD and ACCESS_EXTERNAL_STYLESHEET to an empty string on the TransformerFactory (defensively guarded, matching the pattern in XmlConverter).
• Added FopExternalEntityTest verifying that external DTD/stylesheet access is not resolved during transformation.

Testing

• mvn test -Dtest=FopExternalEntityTest,FopComponentTest in components/camel-fop — all green.

Claude Code on behalf of oscerd

🤖 Generated with Claude Code

[github-actions]

🌟 Thank you for your contribution to the Apache Camel project! 🌟
🤖 CI automation will test this PR automatically.

🐫 Apache Camel Committers, please review the following items:

• First-time contributors require MANUAL approval for the GitHub Actions to run
• You can use the command /component-test (camel-)component-name1 (camel-)component-name2.. to request a test from the test bot although they are normally detected and executed by CI.
• You can label PRs using skip-tests and test-dependents to fine-tune the checks executed by this PR.
• Build and test logs are available in the summary page. Only Apache Camel committers have access to the summary.

⚠️ Be careful when sharing logs. Review their contents before sharing them publicly.

[github-actions]

🧪 CI tested the following changed modules:

• components/camel-fop

---

🔬 Scalpel shadow comparison — Scalpel: 9 tested, 27 compile-only — current: 9 all tested

Maveniverse Scalpel detected 36 affected modules (current approach: 9).

⚠️ Modules only in Scalpel (27)

• apache-camel
• camel-allcomponents
• camel-catalog
• camel-catalog-console
• camel-catalog-maven
• camel-catalog-suggest
• camel-componentdsl
• camel-endpointdsl
• camel-endpointdsl-support
• camel-itest
• camel-jbang-core
• camel-jbang-it
• camel-jbang-main
• camel-jbang-plugin-edit
• camel-jbang-plugin-generate
• camel-jbang-plugin-kubernetes
• camel-jbang-plugin-test
• camel-kamelet-main
• camel-launcher
• camel-report-maven-plugin
• camel-route-parser
• camel-yaml-dsl
• camel-yaml-dsl-deserializers
• camel-yaml-dsl-maven-plugin
• coverage
• docs
• dummy-component

Skip-tests mode would test 9 modules (1 direct + 8 downstream), skip tests for 27 (generated code, meta-modules)

Modules Scalpel would test (9)

• camel-fop
• camel-jbang-mcp
• camel-jbang-plugin-mcp
• camel-jbang-plugin-route-parser
• camel-jbang-plugin-tui
• camel-jbang-plugin-validate
• camel-launcher-container
• camel-yaml-dsl-validator
• camel-yaml-dsl-validator-maven-plugin

Modules with tests skipped (27)

• apache-camel
• camel-allcomponents
• camel-catalog
• camel-catalog-console
• camel-catalog-maven
• camel-catalog-suggest
• camel-componentdsl
• camel-endpointdsl
• camel-endpointdsl-support
• camel-itest
• camel-jbang-core
• camel-jbang-it
• camel-jbang-main
• camel-jbang-plugin-edit
• camel-jbang-plugin-generate
• camel-jbang-plugin-kubernetes
• camel-jbang-plugin-test
• camel-kamelet-main
• camel-launcher
• camel-report-maven-plugin
• camel-route-parser
• camel-yaml-dsl
• camel-yaml-dsl-deserializers
• camel-yaml-dsl-maven-plugin
• coverage
• docs
• dummy-component

ℹ️ Shadow mode — Scalpel observes but does not affect test execution. Learn more

All tested modules (36 modules)

• Camel :: All Components Sync point
• Camel :: Assembly
• Camel :: Catalog :: Camel Catalog
• Camel :: Catalog :: Camel Report Maven Plugin
• Camel :: Catalog :: Camel Route Parser
• Camel :: Catalog :: Console
• Camel :: Catalog :: Dummy Component
• Camel :: Catalog :: Maven
• Camel :: Catalog :: Suggest
• Camel :: Component DSL
• Camel :: Coverage
• Camel :: Docs
• Camel :: Endpoint DSL
• Camel :: Endpoint DSL :: Support
• Camel :: FOP
• Camel :: Integration Tests
• Camel :: JBang :: Core
• Camel :: JBang :: Integration tests
• Camel :: JBang :: MCP
• Camel :: JBang :: Main
• Camel :: JBang :: Plugin :: Edit
• Camel :: JBang :: Plugin :: Generate
• Camel :: JBang :: Plugin :: Kubernetes
• Camel :: JBang :: Plugin :: MCP
• Camel :: JBang :: Plugin :: Route Parser
• Camel :: JBang :: Plugin :: TUI
• Camel :: JBang :: Plugin :: Testing
• Camel :: JBang :: Plugin :: Validate
• Camel :: Kamelet Main
• Camel :: Launcher
• Camel :: Launcher :: Container
• Camel :: YAML DSL
• Camel :: YAML DSL :: Deserializers
• Camel :: YAML DSL :: Maven Plugins
• Camel :: YAML DSL :: Validator
• Camel :: YAML DSL :: Validator Maven Plugin

---

⚙️ View full build and test results