Java 使用JSON进行POST时出现奇怪的ExecutionException_Java_Playframework

Java 使用JSON进行POST时出现奇怪的ExecutionException

java playframework

Java 使用JSON进行POST时出现奇怪的ExecutionException,java,playframework,Java,Playframework,我有这个方法： /** * POST */ public static void create(String body) { Logger.info("APPOINTMENT create - json string: %s", body); Appointment appointment = null; try { appointment = new Gson().fromJson(body, Appointment.class);

我有这个方法：

/**
 * POST
 */
public static void create(String body) {
    Logger.info("APPOINTMENT create - json string: %s", body);

    Appointment appointment = null;
    try {
        appointment = new Gson().fromJson(body, Appointment.class);

        //services are detached, re-take them from db
        List<Service> refreshedServices = new ArrayList<Service>();
        for (final Service ser : appointment.services) {
            Service service = Service.findById(ser.id);
            refreshedServices.add(service);
        }
        appointment.services = refreshedServices;
        appointment.save();
        appointment.refresh();
        Logger.info("services refreshed");
    } catch (Exception ex) {
        Logger
                .info(
                        "An error has occured when trying to create an APPOINTMENT %s",
                        ex);
        response.status = Http.StatusCode.INTERNAL_ERROR;
        renderJSON(new StatusMessage(
                "An internal error has occured. Please try again later."));
    }

    renderJSON(appointment);
}

我也不知道为什么

它打印出

Logger.info（“服务刷新”）之后将引发异常
你们觉得这个测试柱有什么问题吗
更新：问题似乎来自尝试将约会
呈现为JSON:
Caused by: java.lang.StackOverflowError
at java.util.LinkedHashMap$LinkedHashIterator.(LinkedHashMap.java:345)
at java.util.LinkedHashMap$LinkedHashIterator.(LinkedHashMap.java:345)
at java.util.LinkedHashMap$ValueIterator.(LinkedHashMap.java:387)
at java.util.LinkedHashMap$ValueIterator.(LinkedHashMap.java:387)
at java.util.LinkedHashMap.newValueIterator(LinkedHashMap.java:397)
at java.util.HashMap$Values.iterator(HashMap.java:910)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:192)
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:879)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)

通过深入研究错误跟踪，我能够识别问题。基本上，我的Appointment
对象具有一些manytomy
关系，并且在尝试渲染这些关系时，renderJSON似乎给出了StackOverFlow

我已经创建了另一个Appointment
对象，并仅将需要导出的字段复制到其中
    Appointment appointmentOutput = new Appointment();
    appointmentOutput.id = appointment.id;
    appointmentOutput.name = appointment.name;

    renderJSON(appointmentOutput);

这是因为：
Play框架与Google的JSON库Gson捆绑在一起，但是
该库的开发人员做出了一些设计选择，这些选择保持了
它并不适合生成要发送到的JSON
HTTP客户端
Erik Bakker使用我在游戏框架方面没有经验，但我希望能帮助你。谢谢，但没有帮助。。。
Caused by: java.lang.StackOverflowError
at java.util.LinkedHashMap$LinkedHashIterator.(LinkedHashMap.java:345)
at java.util.LinkedHashMap$LinkedHashIterator.(LinkedHashMap.java:345)
at java.util.LinkedHashMap$ValueIterator.(LinkedHashMap.java:387)
at java.util.LinkedHashMap$ValueIterator.(LinkedHashMap.java:387)
at java.util.LinkedHashMap.newValueIterator(LinkedHashMap.java:397)
at java.util.HashMap$Values.iterator(HashMap.java:910)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:192)
at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:879)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)

    Appointment appointmentOutput = new Appointment();
    appointmentOutput.id = appointment.id;
    appointmentOutput.name = appointment.name;

    renderJSON(appointmentOutput);