我有一个非常简单的DTO结构,由一个接口,一个实现它的抽象类和一个抽象类下的类层次结构组成。 界面:
public interface InterfaceDTO {}
抽象类:
import org.codehaus.jackson.annotate.JsonSubTypes;
import org.codehaus.jackson.annotate.JsonSubTypes.Type;
import org.codehaus.jackson.annotate.JsonTypeInfo;
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "json_type")
@JsonSubTypes({
@Type(value = DataDTO.class, name = "DataDTO"),
@Type(value = VectorDTO.class, name = "VectorDTO") })
public abstract class AbstractDTO implements InterfaceDTO {}
第一级课程:
public class DataDTO extends AbstractDTO {
private Short answerId;
private String clientKey;
private String answerText;
.....
public class VectorDTO extends AbstractDTO {
private Vector<InterfaceDTO> answers;
public VectorDTO() {
answers = new Vector<InterfaceDTO>();
}
二级课程:
public class DataWithReplyDTO extends DataDTO {
private String replyData;
最后,restygwt JSON enc / dec代码:
public interface InterfaceDTOCodec extends JsonEncoderDecoder<InterfaceDTO> {}
...
InterfaceDTOCodec codec = GWT.create(InterfaceDTOCodec.class);
VectorDTO dto = new VectorDTO();
JSONValue json = codec.encode(dto);
InterfaceDTO other = codec.decode(json);
...
当我使用GWT 2.6.1和restygwt从eclipse编译时,我得到:
Compiling module com.test.web.MyApp
Computing all possible rebind results for 'com.test.web.client.activity.InitActivity.InterfaceDTOCodec'
Rebinding com.test.web.client.activity.InitActivity.InterfaceDTOCode
Invoking generator org.fusesource.restygwt.rebind.JsonEncoderDecoderGenerator
Generating: com.test.web.client.activity.InitActivity_InterfaceDTOCodec_Generated_ExtendedJsonEncoderDecoder_
checking: org.fusesource.restygwt.client.JsonEncoderDecoder, type: class com.google.gwt.dev.javac.typemodel.JParameterizedType
Generating: com.test.web.shared.dto.InterfaceDTO_Generated_JsonEncoderDecoder_
[ERROR] Abstract classes must be annotated with JsonTypeInfo
[ERROR] Errors in 'com/test/web/client/activity/InitActivity.java'
[ERROR] Line 55: Failed to resolve 'com.test.web.client.activity.InitActivity.InterfaceDTOCodec' via deferred binding
[WARN] For the following type(s), generated source was never committed (did you forget to call commit()?)
[WARN] com.test.web.client.activity.InitActivity_InterfaceDTOCodec_Generated_ExtendedJsonEncoderDecoder_
[WARN] com.test.web.shared.dto.InterfaceDTO_Generated_JsonEncoderDecoder_
按照指南,我在抽象类中添加了注释,但仍然是奇怪的错误消息。有什么帮助吗?
参考文献: http://resty-gwt.github.io/documentation/restygwt-user-guide.html RestyGWT Polymorphic Encode/Decode issues when using an interface instead of an abstract class
答案 0 :(得分:1)
尝试删除DataWithReplyDTO并查看它是否有效。
我猜你不能有2级非抽象类。代码如何知道它是否需要创建DataWithReplyDTO或DataDTO?
答案 1 :(得分:0)
我最终得到了经典的试验和错误,忽略了restygwt的文档。以下是我为了使其发挥作用所做的事情:
@Type(value = DataWithReplyDTO.class, name = "DataWithReplyDTO"),
添加到界面@JsonSubTypes
列表我在单元测试中使用了以下编码器/解码器声明,它起作用了:
public interface InterfaceDTOEncoderDecoder extends JsonEncoderDecoder<InterfaceDTO> {}
结论:似乎你可以在一个接口下有几个级别的继承,只要你将接口中的所有类型声明为@JsonSubTypes