DeprecatedPropertyWarningConfig

Configuration for deprecated property warning behavior.

Spring Boot + Kotlin Binding Pattern Analysis

This configuration class uses var for the Boolean property due to production requirements discovered when using @Configuration classes with CGLIB proxying.

Why var individualLogging: Boolean = false? - PRODUCTION LESSON LEARNED

CGLIB Proxying Requirement: When using @Configuration (not just @ConfigurationProperties), Spring Boot creates CGLIB proxies that require setters for environment variable binding, even for scalar types. Using val causes: "No setter found for property: individual-logging"

Production Error:

Failed to bind properties under 'embabel.agent.platform.migration.warnings'
Property: embabel.agent.platform.migration.warnings.individual-logging
Value: "true"
Origin: System Environment Property "EMBABEL_AGENT_PLATFORM_MIGRATION_WARNINGS_INDIVIDUAL_LOGGING"
Reason: java.lang.IllegalStateException: No setter found for property: individual-logging

Key Distinction: Pure @ConfigurationProperties data classes can use val with constructor binding, but @Configuration + @ConfigurationProperties classes need var for CGLIB proxy compatibility.

Expected Usage Pattern:

# Environment variable binding (requires var with @Configuration classes)
export EMBABEL_AGENT_PLATFORM_MIGRATION_WARNINGS_INDIVIDUAL_LOGGING=true

Spring Boot Property Binding Reality Check:

• ⚠️ Scalar types with @Configuration: var required for CGLIB proxy compatibility

• ❌ Complex types (List, Map): var required for reliable environment variable binding

• ✅ Constructor Binding: Kotlin data classes automatically use constructor binding for val

• ✅ Setter Binding: Properties with var use setter-based binding

Production Decision: Uses var due to CGLIB proxy requirements with @Configuration annotation.

See also