自定义MonetaryAmount JSR354 / moneta数据库Json序列化格式

Question

我试图用MonetaryAmount字段作为字符串序列化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}}

知道我做错什么了吗？我把厨房水槽扔在这里的代码中，只是为了说明性的目的和紧凑的演示。

Answer 1

JsonFormat是杰克逊定义的几个(反)序列化器中使用的注释(例如，DateTimeSerializerBase、NumberSerializers.Base和其他一些完整列表这里)，它不是将任何对象转换为字符串的通用机制：

与大多数其他Jackson注释不同，注释没有特定的通用解释:相反，效果取决于正在注释的属性的数据类型(或者更具体地说，使用反序列化程序和序列化程序)。

除非为MonetaryAmount创建自定义序列化程序，或者使用使用此注释(以及它的pattern属性)的序列化程序，否则指定它不会有任何效果，但如果创建自定义序列化程序，则很可能不需要为不同字段指定不同模式的灵活性，只需使用固定的MonetaryAmountFormat或从MonetaryAmount对象构建必要的字符串即可。

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());
        }
    }
}