Can Jackson be configured to trim leading/trailing whitespace from all string properties?

Question

Example JSON (note that the string has trailing spaces):

{ \"aNumber\": 0, \"aString\": \"string   \" }

Ideally, the deserialised instance

Answer 1

For Spring Boot, we just have to create a custom deserializer as documented in the manual.

The following is my Groovy code but feel free to adapt it to work in Java.

import com.fasterxml.jackson.core.JsonParser
import com.fasterxml.jackson.databind.DeserializationContext
import com.fasterxml.jackson.databind.JsonDeserializer
import org.springframework.boot.jackson.JsonComponent

import static com.fasterxml.jackson.core.JsonToken.VALUE_STRING

@JsonComponent
class TrimmingJsonDeserializer extends JsonDeserializer {

    @Override
    String deserialize(JsonParser parser, DeserializationContext context) {
        parser.hasToken(VALUE_STRING) ? parser.text?.trim() : null
    }
}