Jackson XML - Is there a Java built-in type that can be used to deserialize an object containing arrays?

Question

Let's say my XML is :

<someObject>
  <someArray>
    <element>111</element>
    <element>222</element>
  </someArray>
</someObject>

Is there a Java built-in Type that I can use to deserialize this XML without requiring custom deserialization code?

For example, if I use a Map<Object, Object>, only one element is kept, the other one is overwritten! :

String xmlStr = "<someObject><someArray><element>111</element><element>222</element></someArray></someObject>";
Map<Object, Object> resultObj = getXmlMapper().readValue(xmlStr, new TypeReference<Map<Object, Object>>(){});
System.out.println(resultObj);

This prints :

{someArray={element=222}}

Is there any Type that Jackson understands and that can handle arrays correctly?

Answer 1

In your specific case you could use

new TypeReference<Map<Object, List>> 

output : {someArray=[111, 222]}.

I would much prefer to use a proper structure if there is any more complexity to your XML.

@JacksonXmlRootElement(localName = "someObject")
public static class SomeObject {
    @JacksonXmlProperty(localName = "someArray")
    List<String> someArray; 

    @Override
    // for testing
    public String toString() {
        return someArray.toString();
    }
}

public static void main(String[] args) throws JsonParseException, JsonMappingException, IOException {
    ObjectMapper map = new XmlMapper();
    String xmlStr = "<someObject><someArray><element>111</element><element>222</element></someArray></someObject>";
    SomeObject resultObj = map.readValue(xmlStr, new TypeReference<SomeObject>(){});
    System.out.println(resultObj);      
}

Output

[111, 222]

Alternatively use an array

@JacksonXmlRootElement(localName = "someObject")
public static class SomeObject {
    @JacksonXmlProperty(localName = "someArray")
    String[] someArray; 

    @Override
    public String toString() {
        return Arrays.asList(someArray).toString();
    }
}