java RuntimeTypeAdapterFactory表示“类型”未定义
我正在处理一个需要反序列化的多态类的情况
Class Pen{
String name;
List<Animal> animals;
}
//Animal can be an interface or parent class: I am flexible
Class Animal{
AnimalType type;//enum
int legs;
}
enum AnimalType{
dog,cat,pig,chicken;
}
Class AnimalDog extends Animal{
//…
}
Class AnimalCat extends Animal{
//…
}
Class AnimalPig extends Animal{
//…
}
然后我用
public static Gson instanceUpperCamelCaseWithTypeAdapterFactory() {
if (null == sGsonUpperCamelCase) {
final RuntimeTypeAdapterFactory<Animal> typeFactory = RuntimeTypeAdapterFactory
.of(Animal.class, “type")
.registerSubtype(AnimalDog.class, “dog”)
.registerSubtype(AnimalCat.class, “cat”)
.registerSubtype(AnimalPig.class, “pig”);
sGsonUpperCamelCase = new GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE)
.registerTypeAdapterFactory(typeFactory).create();
}//the naming policy is because server sends me upper case fields whereas Java fields are lowercase.
return sGsonUpperCamelCase;
}
要从包含动物列表的json中获取动物,我需要
List<Animal> animals = gson.fromJson(json, new TypeToken<List<Animal>>() {}.getType());
我对Gson完全是个新手。彻底地所以在不让我太困惑的情况下,我该如何解决这个问题呢
错误跟踪:
com.google.gson.JsonParseException: cannot deserialize class com.company.appname.data.model.Animal because it does not define a field named type
com.company.appname.utils.RuntimeTypeAdapterFactory$1.read(RuntimeTypeAdapterFactory.java:204)
com.google.gson.TypeAdapter$1.read(TypeAdapter.java:199)
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40)
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:82)
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:61)
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:117)
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:217)
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:40)
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:82)
com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:61)
com.google.gson.Gson.fromJson(Gson.java:861)
com.google.gson.Gson.fromJson(Gson.java:826)
com.google.gson.Gson.fromJson(Gson.java:775)
我通过在线验证器运行json,没有问题。它有许多项目。这里我展示两个
{“Animals”:[{
“id":9,
“type”:”dog”,
“name”:”maximus”
},
{
“id":10,
“type”:”cat”,
“name”:”meowy”,
“yarns”:5,
“nice”:true
}]}
共 (0) 个答案