从配置动态读取@JsonProperty

Question

I am developing a Spring boot application which uses Jackson annotations.

I want to read value of @JsonProperty from a config, instead of using constant string.

Example JSON input

{"s":12}

Code

I want to read property from my config:

@JsonProperty("${myconfig.fieldAlias.stream}")
private Integer stream;

instead of

@JsonProperty("s")
private Integer stream;

Issue While executing the code above using config:

variable "s" is not identified as stream

unless I use constant @JsonProperty("s") , which is not desired.

Is it possible to use dynamic JsonProperty values? If so, what is the proper way to do so?

Answer 1

The name given to @JsonProperty must be statically given. What you can do is to overwrite the given name dynamically, by implementing a custom serializer for the propery:

public static class StreamSerializer extends JsonSerializer<Integer> {
    @Override public void serialize(Integer value, JsonGenerator jsonGenerator, SerializerProvider provider)
        throws IOException {
        jsonGenerator.writeStartObject();
        jsonGenerator.writeStringField("s", your_dynamic_name_here);// dynamic field name
        jsonGenerator.writeEndObject();
    }
}

and use it like this:

@JsonProperty("s")
@JsonSerialize(using = StreamSerializer.class)
private Integer stream;