我的POJO：
public class Catalog {
private Integer id;
private Doc doc;
private List<Image> images;
如果传入的json是这样的：
{
"catalog": {
"id": 1,
"doc": {
"url": "some_url",
"deletedAt": "2017-10-20T14:10:01.797Z",
"updatedAt": "2017-10-20T14:10:01.797Z"
},
"images": []
}
}
GSON的成功从json到POJO的成功。 OK！
但如果传入的json是这样的：
{
"catalog": {
"id": 1,
"doc": {
"url": "some_url",
"deletedAt": "2017-10-20T14:10:01.797Z",
"updatedAt": "2017-10-20T14:10:01.797Z"
},
"images": null
}
}
我得错了：
onFailure: Error: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 113 column 17 path $[0].some[0].catalog.images
com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 113 column 17 path $[0].offers[0].catalog.images
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:224)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:129)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:220)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:41)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:82)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:61)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:129)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:220)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.read(TypeAdapterRuntimeTypeWrapper.java:41)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:82)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:61)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:37)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:25)
at retrofit2.ServiceMethod.toResponse(ServiceMethod.java:119)
at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:218)
at retrofit2.OkHttpCall$1.onResponse(OkHttpCall.java:112)
at okhttp3.RealCall$AsyncCall.execute(RealCall.java:141)
at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 113 column 17 path $[0].offers[0].catalog.images
at com.google.gson.stream.JsonReader.beginArray(JsonReader.java:350)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:80)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:61)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:129)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:220)
这是因为字段＆＃34; 图像＆＃34;是空的。
当值 null 时，如何忽略（不反序列化）字段？
或许还有另一个好的解决方案？例如。将null转换为空列表。