我遇到了Jackson和类型层次结构的问题。 我正在将一个扩展
我查看了以下问题/资源: 这些资源提供了有关使用Jackson进行多态反序列化的信息。
Base
的类 SubA
序列化为一个 String
,然后尝试将其反序列化回来。 当然在编译时,系统不知道它将是 Base
还是 SubA
,所以我期望得到一个 Base
,并在之后进行其他操作(如果它是 SubA
)。
我的 Base
类如下:
@JsonTypeInfo(
use = JsonTypeInfo.Id.NAME,
include = JsonTypeInfo.As.PROPERTY,
property = "type")
@JsonSubTypes({
@Type(value = SubA.class, name = "SubA")
})
public class Base {
protected String command; // +get +set
protected String type; // +get +set
}
...以及从Base
派生出的类:
@JsonTypeName("SubA")
public class SubA extends Base {
private AnotherClass anotherClass; // +get +set
private String test; // +get +set
@JsonIgnore
@Override
public String getType() {
return "SubA";
}
}
...我正在尝试执行以下代码:
ObjectMapper mapper = new ObjectMapper();
ObjectWriter ow = mapper.writer().withDefaultPrettyPrinter();
Base payload = new SubA(); // + setting anotherClass as well as test variables
String requestStringSend = ow.writeValueAsString(payload);
System.out.println("Sending: " + requestStringSend);
Base received = mapper.readValue(requestStringSend, Base.class);
String requestStringReceived = ow.writeValueAsString(received);
System.out.println("Received: " + requestStringReceived);
requestStringSend
字符串内容如下:
Sending: {
"command" : "myCommand",
"type" : "SubA",
"anotherClass" : {
"data" : "someData"
},
"test" : "test123"
}
但是我一遍又一遍地得到同样的错误。映射器不知道如何处理anotherClass
参数 - 在Base
中不存在。但我认为映射器会将其转换为SubA
类?
Exception in thread "main" org.codehaus.jackson.map.exc.UnrecognizedPropertyException: Unrecognized field "anotherClass" (Class com.test.Base), not marked as ignorable
at [Source: java.io.StringReader@1256ea2; line: 4, column: 21] (through reference chain: com.test.Base["anotherClass"])
at org.codehaus.jackson.map.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:53)
at org.codehaus.jackson.map.deser.StdDeserializationContext.unknownFieldException(StdDeserializationContext.java:267)
at org.codehaus.jackson.map.deser.std.StdDeserializer.reportUnknownProperty(StdDeserializer.java:649)
at org.codehaus.jackson.map.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:635)
at org.codehaus.jackson.map.deser.BeanDeserializer.handleUnknownProperty(BeanDeserializer.java:1355)
at org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:717)
at org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java:580)
at org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java:2723)
at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1854)
at com.test.Foo.main(Foo.java:32)
我查看了以下问题/资源: 这些资源提供了有关使用Jackson进行多态反序列化的信息。
Jackson
?我检查了你的Jackson
2.3.2 (com.fasterxml.jackson) 示例,一切正常。 - Michał Ziober