我正在与杰克逊一起使用改造。由于某些原因,我无法解析以下 JSON:
[
{
"ProfileImage": null,
"UserName": "joe"
},
{
"ProfileImage": "http://www.example.com/profiles/fileName1.jpg",
"UserName": "jane"
},
{
"ProfileImage": null,
"UserName": "john"
}
]
我得到了这个例外:
Exception in thread "main" retrofit.RetrofitError: java.lang.ClassCastException:
sun.reflect.generics.reflectiveObjects.ParameterizedTypeImpl
cannot be cast to java.lang.Class
at retrofit.RetrofitError.unexpectedError(RetrofitError.java:41)
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:294)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:182)
at com.sun.proxy.$Proxy5.getReplies(Unknown Source)
at Test.main(Test.java:25)
Caused by: java.lang.ClassCastException:
sun.reflect.generics.reflectiveObjects.ParameterizedTypeImpl
cannot be cast to java.lang.Class
at JacksonConverter.fromBody(JacksonConverter.java:27)
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:274)
我的代码如下:
//文件:Test.java:
public class Test {
public static void main(String[] args) {
ObjectMapper mapper = new ObjectMapper();
mapper.setPropertyNamingStrategy(new PropertyNamingStrategy
.PascalCaseStrategy());
RestAdapter restAdapter = new RestAdapter.Builder()
.setServer("http://www.example.com")
.setConverter(new JacksonConverter(mapper))
.build();
ListingService listingService = restAdapter.create(ListingService.class);
ArrayList<ListingReplyExt> replies = listingService.getReplies(123, 1, 10);
//More code...
}
}
//文件:ListingService.java
public interface ListingService {
@GET("/api/ListingRepliesService.svc/Get")
public ArrayList<ListingReplyExt> getReplies(
@Query("listingId") long listingId,
@Query("start") int start,
@Query("count") int count);
}
//文件:ListingReplyExt.java:
@JsonIgnoreProperties(ignoreUnknown = true)
public class ListingReplyExt {
private String profileImage;
private String username;
@JsonProperty(value = "ProfileImage")
public String getProfileImage() {
return profileImage;
}
@JsonProperty(value = "ProfileImage")
public void setProfileImage(String profileImage) {
this.profileImage = profileImage;
}
@JsonProperty(value = "UserName")
public String getUsername() {
return username;
}
@JsonProperty(value = "UserName")
public void setUsername(String username) {
this.username = username;
}
}
任何帮助都会得到帮助。
更新
Sotirios Delimanolis 的评论给了我一些解决这个问题的提示。
我的 JacksonConverter 最初是这样的:
public class JacksonConverter implements Converter {
private final ObjectMapper objectMapper;
public JacksonConverter(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
}
@Override public Object fromBody(TypedInput body, Type type) {
return objectMapper.readValue(body.in(), (Class<Object>) type);
}
//More code
}
我把它改成这样:
public class JacksonConverter implements Converter {
private final ObjectMapper objectMapper;
public JacksonConverter(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
}
@Override public Object fromBody(TypedInput body, Type type) {
JavaType javaType = objectMapper.getTypeFactory().constructType(type);
return objectMapper.readValue(body.in(), javaType);
}
//More code
}
现在它对我有用。