Jackson - Don't use @JsonProperty with @JsonPOJOBuilder or @JsonCreator ctor

Question

Preconditions:

• Java/Spring Boot
• PropertyNamingStrategy.UpperCamelCaseStrategy is set
• DTO classes fields are camel case
• Json fields are upper camel case
• DTO/Json field names are aligned
• Keep DTO classes immutable, avoiding the use of setters for fields

Requirement:

• Deserialize without using @JsonProperty in DTO class (implicitly)

Tried to use nested builder class with @JsonPOJOBuilder or constructor, annotated with @JsonCreator , however:

• @JsonPOJOBuilder annotated Builder class without @JsonPropery on setField() methods - setField() methods not being called by Jackson on deserialization
• Constructor with @JsonCreator annotation - explicitly requires @JsonProperty on parameters

Answer 1

I have written a blog post with a solution for this. In summary:

1. use Java 1.8
2. compile with -parameters argument
3. use and register jackson-module-parameter-names

The above will result in Jackson finding the names of the arguments of the constructor in the bytecode without requiring either @JsonCreator or @JsonProperty on the constructor.

Regardig the naming strategy you can easily set it at applications.properties and although I haven't tested it, should work with the non-annotated constructor.

Answer 2

When using @JsonCreator use camel case.

I used snake case in below example. @JsonCreator public ApiResponseBuilder(@JsonProperty("status_code")int statusCode, @JsonProperty("status_message")String statusMessage) {