xstream conversion exception on deserialization

Question

I am facing below exception while deserialization using xstream:

com.thoughtworks.xstream.converters.ConversionException: Element service of type com.config.Service is not defined as field in type com.config.Service

---- Debugging information ----

class : com.config.ServiceNServiceConfigurations

required-type : com.config.Service

path : /root/services/service

My XML is :

<root>
    <services>
      <service>
        <Id>10</Id>
        <Name>CM</Name>
      </service>
      <service>
        <Id>11</Id>
        <Name>TM</Name>
      </service>
    </services>
    <serviceConfigurations>
      <serviceConfiguration>
        <Key>XYZ</Key>
        <Value>42</Value>
      </serviceConfiguration>
      <serviceConfiguration>
        <Key>ABC</Key>
        <Value>5</Value>
      </serviceConfiguration>
    </serviceConfigurations>
</root>

I created one class corresponding to root tag as below :

public class ServiceNServiceConfigurations implements Serializable {
    private List<ServiceConfiguration> serviceConfigurations;
    private List<Service> services;
    // setter and getter methods
}
public class Service implements Serializable {
    private String Id;
    private String Name;
    // setter and getter methods
}
public class ServiceConfiguration implements Serializable{
    private String key; 
    private String value;
    // setter and getter methods
}

In Test class for deserialization , i wrote below code :

   XStream xstream = new XStream();
        xstream.alias("root", com.config.ServiceNServiceConfigurations.class);
        xstream.alias("service",com.config.Service.class);
        xstream.alias("serviceConfiguration",com.config.ServiceConfiguration.class);
        xstream.addImplicitCollection(ServiceNServiceConfigurations.class, "services", Service.class);
        xstream.addImplicitCollection(ServiceNServiceConfigurations.class, "serviceConfigurations", ServiceConfiguration.class);
        xstream.aliasField("Key", com.config.ServiceConfiguration.class, "key");
        xstream.aliasField("Value", com.config.ServiceConfiguration.class, "value");
        At below line Conversion Exception is coming
obj = xstream.fromXML(xmlSerialized);

Kindly guide me where I am going wrong.

Thanks

Answer 1

You should remove addImplicitCollection configurations, because your collections are not implicit.

XStream xstream = new XStream();
        xstream.alias("root", com.config.ServiceNServiceConfigurations.class);
        xstream.alias("service",com.config.Service.class);
        xstream.alias("serviceConfiguration",com.config.ServiceConfiguration.class);
        xstream.aliasField("Key", com.config.ServiceConfiguration.class, "key");
        xstream.aliasField("Value", com.config.ServiceConfiguration.class, "value");

If they would be implicit your xml would look like this:

<root>
  <serviceConfiguration>
    <Key>XYZ</Key>
    <Value>42</Value>
  </serviceConfiguration>
  <serviceConfiguration>
    <Key>ABC</Key>
    <Value>5</Value>
  </serviceConfiguration>
  <service>
    <Id>10</Id>
    <Name>CM</Name>
  </service>
  <service>
    <Id>11</Id>
    <Name>TM</Name>
  </service>
</root>