Unmarshall exception for SOAP done with contract-first Spring-WS - spring

Question

I am trying to code my first SOAP web service.
I am getting the SOAP response Unmarshall failure
which is the response i mapped to org.springframework.oxm.UnmarshallingFailureException.
I have configured Spring to use Castor (un)marshaller.
Problem is i don't know how to find a more specific cause.
public class SentenceRequest {
public SentenceRequest() {}
private List<String> words = new ArrayList<String>();
public List<String> getWords() {
return words;
}
public void setWords(List<String> words) {
this.words = words;
}
public class SentenceResponse {
private String sentence;
public SentenceResponse() {}
public SentenceResponse(String sen) {
sentence = sen;
}
public String getSentence() {
return sentence;
}
public void setSentence(String sentence) {
this.sentence = sentence;
}
the castor mapping:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapping PUBLIC
"-//EXOLAB/Castor Object Mapping DTD Version 1.0//EN"
"http://castor.exolab.org/mapping.dtd">
<mapping xmlns="http://castor.exolab.org/">
<class name="ro.soapservice2.SentenceRequest">
<map-to xml="SentenceRequest" ns-uri="sentence" ns-prefix="s" />
<field name="words" collection="arraylist" type="java.util.List" required="true">
<bind-xml name="word" node="element"></bind-xml>
</field>
</class>
<class name="ro.soapservice2.SentenceResponse">
<map-to xml="SentenceResponse" ns-uri="sentence" ns-prefix="s" />
<field name="sentence" type="java.lang.String" required="true">
<bind-xml name="sentence" node="element" />
</field>
</class>
</mapping>
the schema (generated with Trang.jar based on two input XML files):
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="sentence" xmlns:s="sentence">
<xs:element name="SentenceRequest">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded" ref="s:word"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="word" type="xs:string"/>
<xs:element name="SentenceResponse">
<xs:complexType>
<xs:sequence>
<xs:element ref="s:sentence"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="sentence" type="xs:string"/>
</xs:schema>
and the WSDL Spring generates:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<wsdl:definitions xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:sch="sentence" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:tns="sentence" targetNamespace="sentence">
<wsdl:types>
<xs:schema xmlns:s="sentence" xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" targetNamespace="sentence">
<xs:element name="SentenceRequest">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="unbounded" ref="s:word"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="word" type="xs:string"/>
<xs:element name="SentenceResponse">
<xs:complexType>
<xs:sequence>
<xs:element ref="s:sentence"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="sentence" type="xs:string"/>
</xs:schema>
</wsdl:types>
<wsdl:message name="SentenceResponse">
<wsdl:part element="tns:SentenceResponse" name="SentenceResponse">
</wsdl:part>
</wsdl:message>
<wsdl:message name="SentenceRequest">
<wsdl:part element="tns:SentenceRequest" name="SentenceRequest">
</wsdl:part>
</wsdl:message>
<wsdl:portType name="Sentence">
<wsdl:operation name="Sentence">
<wsdl:input message="tns:SentenceRequest" name="SentenceRequest">
</wsdl:input>
<wsdl:output message="tns:SentenceResponse" name="SentenceResponse">
</wsdl:output>
</wsdl:operation>
</wsdl:portType>
<wsdl:binding name="SentenceSoap11" type="tns:Sentence">
<soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
<wsdl:operation name="Sentence">
<soap:operation soapAction=""/>
<wsdl:input name="SentenceRequest">
<soap:body use="literal"/>
</wsdl:input>
<wsdl:output name="SentenceResponse">
<soap:body use="literal"/>
</wsdl:output>
</wsdl:operation>
</wsdl:binding>
<wsdl:service name="SentenceService">
<wsdl:port binding="tns:SentenceSoap11" name="SentenceSoap11">
<soap:address location="http://localhost:8080/soapservice2/services"/>
</wsdl:port>
</wsdl:service>
</wsdl:definitions>
the SOAP request i make:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:sen="sentence">
<soapenv:Header/>
<soapenv:Body>
<sen:SentenceRequest>
<!--1 or more repetitions:-->
<sen:word>asd</sen:word>
</sen:SentenceRequest>
</soapenv:Body>
</soapenv:Envelope>

Answer 1

Solved!
First i replaced my exception resolver from
org.springframework.ws.soap.server.endpoint.SoapFaultMappingExceptionResolver
to
org.springframework.ws.soap.server.endpoint.SimpleSoapExceptionResolver
which puts back in the SOAP response the real exception that was thrown.
Then i saw the problem was at the Castor xml mapping file:
changed from
<field name="words" collection="arraylist" type="java.util.List" required="true">
<bind-xml name="word" node="element"></bind-xml>
</field>
to
<field name="words" collection="arraylist" type="java.lang.String" required="true">
<bind-xml name="word" node="element"></bind-xml>
</field>