XML deserialization to POJO using Jackson XmlMapper

Question

Using Jackson XmlMapper annotations, how would I deserialize this XML into a pojo?

<?xml version="1.0" encoding="UTF-8"?>
<open>
   <creds priv="write" type="internal">
      <user>Username1</user>
      <client_token>abcplaudzrbcy37c</client_token>
      <client_secret>0cxDE3LE0000=</client_secret>
   </creds>
   <creds priv="read" type="internal">
      <user>Username1</user>
      <client_token>123plaudzrbcy37c</client_token>
      <client_secret>0cxDE3LE1234=</client_secret>
   </creds>
   <creds priv="none" type="internal">
      <user>Username1</user>
      <client_token>000plaudzrbcy37c</client_token>
      <client_secret>0cxDE3LEabcd=</client_secret>
   </creds>
</open>

I attempted to use something like this:

@JacksonXmlRootElement(localName = "Open")
public class OpenCredentials {

    @JacksonXmlProperty(localName = "Credentials")
    private Credentials[] credentials;

}


class Credentials {

    @JacksonXmlProperty(isAttribute = true)
    private String priv;

    @JacksonXmlProperty(isAttribute = true)
    private String type;

    @JacksonXmlProperty(localName = "Creds")
    private Creds[] creds;
}


class Creds {

    @JacksonXmlText(value = true)
    private String user;

    @JacksonXmlText(value = true)
    private String client_token;

    @JacksonXmlText(value = true)
    private String client_secret;
}

When I tried to use XmlMapper's readValue(), I get the following error:

com.fasterxml.jackson.databind.JsonMappingException: Duplicate property '' for [simple type, class com.company.data.utils.api.Creds]
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:268)
at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:243)

Answer 1

Your POJO classes do not fit to your XML. The structure is simpler than you thought. See below example:

@JacksonXmlRootElement(localName = "open")
class OpenCredentials {

    @JacksonXmlProperty(localName = "creds")
    @JacksonXmlElementWrapper(useWrapping = false)
    private Credentials[] credentials;

    //getters, setters, toString
}


class Credentials {

    @JacksonXmlProperty(isAttribute = true)
    private String priv;

    @JacksonXmlProperty(isAttribute = true)
    private String type;

    private String user;

    @JacksonXmlProperty(localName = "client_token")
    private String clientToken;

    @JacksonXmlProperty(localName = "client_secret")
    private String clientSecret;

    //getters, setters, toString
}

Simple usage:

XmlMapper mapper = new XmlMapper();
OpenCredentials openCredentials = mapper.readValue(XML, OpenCredentials.class);
System.out.println(openCredentials);

Above program prints (for your XML):

OpenCredentials{credentials=[Credentials{priv='write', type='internal', user='Username1', client_token='abcplaudzrbcy37c', client_secret='0cxDE3LE0000='}, Credentials{priv='read', type='internal', user='Username1', client_token='123plaudzrbcy37c', client_secret='0cxDE3LE1234='}, Credentials{priv='none', type='internal', user='Username1', client_token='000plaudzrbcy37c', client_secret='0cxDE3LEabcd='}]}

See also:

1. jackson-dataformat-xml.
2. Home: Jackson XML databind Wiki.