如何将Java / Scala对象转换为Protocol Buffers消息？

Question

我正在尝试将Java / Scala对象转换为Protocol Buffers消息。

我的对象名为IDSNumber，它有doubleValue方法，返回java.lang.Double。我试图让它在Dozer对象转换期间自动转换为double。

我在Scala中创建了一个Dozer Custom Converter，这里：

class IDSConverter extends DozerConverter[IDSNumber, java.lang.Double](classOf[IDSNumber], classOf[java.lang.Double]) {
    def convertTo(source: IDSNumber, destination: java.lang.Double): java.lang.Double = {
        source.doubleValue()
    }
    def convertFrom(source: java.lang.Double , destination: IDSNumber): IDSNumber = {
        new IDSNumber(source)
    }
}

My Protocol Buffers消息如下所示（shortFee和longFee应该从IDSNumber类型转换）：

message PerformanceSettingMessage {
    optional string                  displayCurrency           = 1;
    optional PeriodMessage           performancePeriod         = 2;
    optional int64                   conversionDate            = 3;
    optional BenchmarkOptionsMessage benchmarkOptions          = 4;
    optional string                  investmentStrategyMeaning = 5;
    optional double                  shortFee                  = 6;
    optional double                  longFee                   = 7;
}

我尝试以下列方式使用转换器：

    val longFee  = new IDSNumber(2.0)
    val shortFee = new IDSNumber(3.0)
    // newing up a real performance settings object with IDSNumbers for shortFee and longFee
    val performanceSettings = new PerformanceSettings(Currency.apply("$"), period, fj.data.Option.none(), fj.data.Option.none(), Investment_Weighted, shortFee, longFee)

    val mapper = new DozerBeanMapper() // new DozerMapper
    val idsConverter = new IDSConverter() // my IDSNumber converter
    mapper.setCustomConverters(java.util.Arrays.asList(idsConverter)) // make it use my IDSNumber converter
    val msg = mapper.map(performanceSettings, classOf[PerformanceSettingMessage]) // map my real performanceSettings object to my PerformanceSettingsMessage generated by Protocol Buffers

当我运行上述代码时，msg将shortFee和longFee都设置为0.0，而不是2.0和3.0。对我做错了什么的想法？也许有更好的方法（更好的库？）来回转换这些对象？谢谢！