自定义 Databind Json MonetaryAmount JSR354 / moneta 的序列化格式

Question

我正在尝试 Json 将带有 MonetaryAmount 字段的 POJO 序列化为字符串，但生成的输出不遵循规定的形状格式。

// org.javamoney:moneta:1.1 
// com.fasterxml.jackson.core:jackson-annotations:2.7.0
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({
        "CBNOT_CHARGEBACK_AMOUNT"
})
public class TestMonetaryAmountJsonSerialization {
        @JsonProperty("CBNOT_CHARGEBACK_AMOUNT")
        @NotNull
        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "¤#,##0.00", locale = "en_US")
        private final MonetaryAmount chargebackAmount = Monetary.getDefaultAmountFactory().setCurrency("USD").setNumber(12.50).create();

        private static final ObjectMapper mapper = new ObjectMapper();

        @Test
        public void testThis() throws JsonProcessingException{
            String json = mapper.writeValueAsString(this);
            System.out.println(json);
            Assert.assertEquals("{\"CBNOT_CHARGEBACK_AMOUNT\":\"¤12.50\"}",json);
        }

}

OUTPUT: {"CBNOT_CHARGEBACK_AMOUNT":{"currency":{"context":{"empty":false,"providerName":"java.util.Currency"},"defaultFractionDigits":2,"currencyCode":"USD","numericCode":840},"number":12.5,"factory":{"defaultMonetaryContext":{"precision":0,"fixedScale":false,"amountType":"org.javamoney.moneta.Money","maxScale":63,"empty":false,"providerName":null},"maxNumber":null,"minNumber":null,"amountType":"org.javamoney.moneta.Money","maximalMonetaryContext":{"precision":0,"fixedScale":false,"amountType":"org.javamoney.moneta.Money","maxScale":-1,"empty":false,"providerName":null}},"context":{"precision":0,"fixedScale":false,"amountType":"org.javamoney.moneta.Money","maxScale":63,"empty":false,"providerName":null},"numberStripped":12.5,"zero":false,"negative":false,"negativeOrZero":false,"positive":true,"positiveOrZero":true}}

知道我做错了什么吗？我把厨房水槽扔在这段代码里，只是为了说明和紧凑的展示。

Answer 1

JsonFormat is an annotation used in several (de)serializers defined by Jackson (e.g. DateTimeSerializerBase, NumberSerializers.Base and some other, full list here)，这不是将任何对象转换为字符串的通用机制：

Unlike most other Jackson annotations, annotation does not have specific universal interpretation: instead, effect depends on datatype of property being annotated (or more specifically, deserializer and serializer being used).

指定它不会有任何效果，除非您为 MonetaryAmount 创建一个自定义序列化程序或使用一个利用此注释（以及它的 pattern 属性）的序列化程序，但是如果你创建一个自定义序列化器，你可能不需要那种为不同字段指定不同模式的灵活性，并且可以只使用固定的 MonetaryAmountFormat 或从 MonetaryAmount 构建必要的字符串否则反对。

例如

@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({
        "CBNOT_CHARGEBACK_AMOUNT"
})
public class TestMonetaryAmountJsonSerialization {
    @JsonProperty("CBNOT_CHARGEBACK_AMOUNT")
    @NotNull
    private final MonetaryAmount chargebackAmount = Monetary.getDefaultAmountFactory().setCurrency("USD").setNumber(12.50).create();

    private static final ObjectMapper mapper = new ObjectMapper();
    static {
        SimpleModule monetaryModule = new SimpleModule();
        monetaryModule.addSerializer(MonetaryAmount.class, new MonetaryAmountSerializer());
        mapper.registerModule(monetaryModule);
    }

    @Test
    public void testThis() throws JsonProcessingException {
        String json = mapper.writeValueAsString(this);
        System.out.println(json);
        Assert.assertEquals("{\"CBNOT_CHARGEBACK_AMOUNT\":\".50\"}", json);
    }

    public static class MonetaryAmountSerializer extends JsonSerializer<MonetaryAmount> {
        public void serialize(MonetaryAmount monetaryAmount,
                              JsonGenerator jsonGenerator,
                              SerializerProvider serializerProvider) throws IOException {
            StringBuilder sb = new StringBuilder();
            MonetaryAmountDecimalFormatBuilder
                    .of("¤#,##0.00").withCurrencyUnit(monetaryAmount.getCurrency()).build()
                    .print(sb, monetaryAmount);
            jsonGenerator.writeString(sb.toString());
        }
    }
}

自定义 Databind Json MonetaryAmount JSR354 / moneta 的序列化格式

Customizing Databind Json serialization format of MonetaryAmount JSR354 / moneta

java

serialization

json

jackson

jsr354