知道为什么我从下面的代码中得到这个错误？....
PrintWriter writer = response.getWriter();
Collection<Alert> alerts = AppState.instance.bi.getBackend().getNewerAlerts(time);
System.out.println("Alerts size = " + alerts.size());
Gson gson = gsonBuilder.create();
gson.toJson(new AlertsResponse(alerts), AlertsResponse.class, writer);
java.util.LinkedHashMap中的线程"http-bio-80-exec-11"java.lang.StackOverflowError中的异常java.util.LinkedHashMap中的$ LinkedHashIterator.(未知来源)$ java.util中的$ LinkedHashIterator.(未知来源). java.util.LinkedHashMap中的LinkedHashMap $ ValueIterator.(未知来源)$ java.util.HashMap中的java.util.LinkedHashMap.newValueIterator(未知来源)的$ ValueIterator.(未知来源)$ com中的Values.iterator(未知来源).位于com.google.gson.internal的com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)上的google.gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:192). com的bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89).位于com.google.gson.internal的com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)上的google.gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:195). com.google.gson.internal.bind.ObjectTypeAdapter.write中的com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:195)中的bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89) (ObjectTypeAdapter.java:105)com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89)在com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:195)位于com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory) .java:89)com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:195)at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:105)at at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89)at com.google.gson.internal .bind.ReflectiveTypeAdapterFactory $适配器.在com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)上编写(ReflectiveTypeAdapterFactory.java:195)com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89) )com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:195)位于com.google的com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:105). gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)位于com.google.gson.internal.bind.ReflectiveTypeAdapterFactory的com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89) $ Adapter.write(ReflectiveTypeAdapterFactory.java:195)com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)com.google上的com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ 1.write(ReflectiveTypeAdapterFactory.java:89).位于com.google.gson.internal.bind的com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:105)中的gson.internal.bind.ReflectiveTypeAdapterFactory $ Adapter.write(ReflectiveTypeAdapterFactory.java:195). Com.google.gson.internal.bind.ReflectiveTypeAdapterFactory $ …