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

Question

我正在尝试使用MonetaryAmount字段作为字符串将Json序列化为POJO，但结果输出不符合规定的形状格式。

// 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}}

有什么想法我做错了什么？ 我在这里的代码中扔了厨房水槽，仅用于说明目的和紧凑的演示。

Answer 1

JsonFormat是由杰克逊（例如，定义了几种（反）序列化使用的注释DateTimeSerializerBase ， NumberSerializers.Base和一些其他的，完整的列表在这里 ），它不是一个通用的机制转向任何对象转换为字符串：

与大多数其他杰克逊注释不同，注释没有特定的通用解释：相反，效果取决于被注释的属性的数据类型（或更具体地说，使用反序列化器和序列化器）。

指定它将没有任何影响，除非您为MonetaryAmount创建自定义序列化程序或使用一个使用此批注（以及它的pattern属性），但如果您创建自定义序列化程序，您可能不需要该级别灵活性，以指定不同字段的不同模式，并可以使用固定的MonetaryAmountFormat或从MonetaryAmount对象构建必要的字符串。

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\":\"$12.50\"}", 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());
        }
    }
}