Java sprintboot saving one JSON field to two Java fields without setters

Question

I am using sprintboot and I have a model like:

public class Source {

    @NotNull
    @NSDash
    @ValidStandardRulePluritent
    @ValidStandardRuleIPS
    @ValidStandardRuleLasto
    @ValidStandardRuleSomact
    @ValidStandardRuleSotipo
    @NotCompatibleForAlg
    @NotCompatibleForAdaq
    @RuleXioISO
    @JsonDeserializer(using=XioDeserializer.class)
    public String ambian1;
    
    public String raw_ambian1;

    @NotNull
    @NSDash
    @ValidStandardRuleIPS
    @ValidStandardRuleLasto
    @ValidStandardRuleSotipo
    @NotCompatibleForAlg
    @NotCompatibleForAdaq
    public String xebian1;

    public String raw_xebian1;

    # i have more than 100+ other field use this:
    
}

I want to parse this data into a fixed version, but still retain the original raw version.

{"ambian1":"a--1.1-bc.8i", "xebian1":"x--2.1-za.5t", and rest of data}

The ambian1 data can't start with a number.

• "a--1.1-bc.8i" would be valid
• "1a--1.1-bc.8i" would be invalid

So I want my java class to get parsed as:

ambian1 = a--1.1-bc.8i raw_ambian1 = 1a--1.1-bc.8i

I tried to use @JsonAlias but it didn't work. I also tried to use @JsonProperty but I got error: Multiple fields representing property .

public class Source {

    @NotNull
    # other
    @JsonProperty("ambian1");
    public String ambian1;
    
    @JsonAlias("ambian1");
    public String raw_ambian1;

    @NotNull
    # other
    public String xebian1;

    # i have more than 100+ other field use this:
    
}

How can I decode the json value into two fields?

Answer 1

The issue is not in the setters.

If you have all public fields in your model you should not be worried about multiple getters/setters at all as Jackson will handle them automatically when serializing/deserializing.

However, if you want to assign the same/similar value from a single JSON property "data" to two fields "fixData" and "rawData" it would be ok to implement just one setter for these two fields and mark it as @JsonProperty .

Possibly, a getter should be implemented as well to get specific property "data" .

If null fields must be hidden, @JsonInclude should be used to include non-null values.

@JsonInclude(JsonInclude.Include.NON_NULL)
class Source {

    @NotNull
    public String rawData;
    @NotNull
    public String fixData;

    @JsonAlias("another")
    public String anotherField;
    @JsonAlias("yet")
    public Integer yetAnotherField;
    @JsonAlias("onemore")
    public Double oneMoreField;

    @JsonProperty("data")
    public void setRawData(String data) {
        this.rawData = data;  // setting into raw
        this.fixData = data.replaceAll("^(\\d+)", ""); // removing digits at the start
    }

    @JsonProperty("data")
    public String getFixData() {
        return this.fixData; // getting fixed valid value
    }
}

Then the following JSONs could be read successfully:

String[] jsons = {
        "{\"data\":\"1abc\"}",
        "{\"data\":\"2abc\", \"another\":\"an\", \"yet\":100500, \"onemore\":3.14}",
        "{\"data\":\"3abc\", \"anotherField\":\"2VALS\"}"
};

ObjectMapper mapper = new ObjectMapper();
for (String json: jsons) {
    Source set = mapper.readValue(json, Source.class);
    System.out.printf("Setter raw: '%s', input: '%s'%n", set.rawData, set.fixData);

    String serialized = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(set);
    System.out.println("set: " + serialized);
}

Output:

Setter raw: '1abc', input: 'abc'
set: {
  "data" : "abc"
}
Setter raw: '2abc', input: 'abc'
set: {
  "anotherField" : "an",
  "yetAnotherField" : 100500,
  "oneMoreField" : 3.14,
  "data" : "abc"
}
Setter raw: '3abc', input: 'abc'
set: {
  "anotherField" : "2VALS",
  "data" : "abc"
}

"rawData" or "fixData" will not be parsed in JSON.