Spring RestTemplate failure with upper case element names - spring-mvc

Question

I have a simple Spring MVC application that makes an Ajax call to a ReST service using the RestTemplate class. Some of the elements in the schema start with uppercase letters. The 2 elements (code, message) with lowercase letters cause no problems. The classes generated by JAXB have the #XmlElement annotation and name property. This seems to be ignored. I've read that the JaxbAnnotationIntrospector needs to be used but none of the changes make that take effect. See class below. I've tried adding a bean class definition for RestTemplate in the Spring config, adding an object mapper but nothing helps. See error on OTPRO element in first few lines of stack trace:
[4/18/16 9:52:43:988 EDT] 00000024 SystemErr R org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Unrecognized field "OTPRO" (class com.ssdr.rest.message.SSDRResponse), not marked as ignorable (7 known properties: "dt", "ot", "message", "otpro", "otphone", "code", "dtphone"])
at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream#4ccbe679; line: 4, column: 14] (through reference chain: com.ssdr.rest.message.SSDRResponse["OTPRO"]); nested exception is com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "OTPRO" (class com.ssdr.rest.message.SSDRResponse), not marked as ignorable (7 known properties: "dt", "ot", "message", "otpro", "otphone", "code", "dtphone"])
at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream#4ccbe679; line: 4, column: 14] (through reference chain: com.ssdr.rest.message.SSDRResponse["OTPRO"])
[4/18/16 9:52:44:019 EDT] 00000024 SystemErr R at org.springframework.http.converter.json.MappingJackson2HttpMessageConverter.readInternal(MappingJackson2HttpMessageConverter.java:126)
[4/18/16 9:52:44:019 EDT] 00000024 SystemErr R at org.springframework.http.converter.AbstractHttpMessageConverter.read(AbstractHttpMessageConverter.java:153)
[4/18/16 9:52:44:019 EDT] 00000024 SystemErr R at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:81)
JAXB generated class:
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlType;
/**
* <p>Java class for documentResponse complex type.
*
* <p>The following schema fragment specifies the expected content contained within this class.
*
* <pre>
* <complexType name="documentResponse">
* <complexContent>
* <restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
* <sequence>
* <element name="code" type="{http://www.w3.org/2001/XMLSchema}string"/>
* <element name="message" type="{http://www.w3.org/2001/XMLSchema}string"/>
* <element name="OTPRO" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
* <element name="OT" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
* <element name="OTPhone" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
* <element name="DT" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
* <element name="DTPhone" type="{http://www.w3.org/2001/XMLSchema}string" minOccurs="0"/>
* </sequence>
* </restriction>
* </complexContent>
* </complexType>
* </pre>
*
*
*/
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "documentResponse", propOrder = {
"code",
"message",
"otpro",
"ot",
"otPhone",
"dt",
"dtPhone"
})
public class DocumentResponse {
#XmlElement(required = true)
protected String code;
#XmlElement(required = true)
protected String message;
#XmlElement(name = "OTPRO", nillable = true)
protected String otpro;
#XmlElement(name = "OT", nillable = true)
protected String ot;
#XmlElement(name = "OTPhone", nillable = true)
protected String otPhone;
#XmlElement(name = "DT", nillable = true)
protected String dt;
#XmlElement(name = "DTPhone", nillable = true)
protected String dtPhone;
...
Service class:
SSDRResponse resp = null;
RestTemplate restTemplate = new RestTemplate();
HttpEntity<SSDRRequest> httpRequest = new HttpEntity<SSDRRequest>(req, createHeaders());
resp = restTemplate.postForObject(SERVICE_URI, httpRequest, SSDRResponse.class);
Spring config:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">
<context:annotation-config />
<!-- Scans the classpath of this application for #Components to deploy as beans -->
<context:component-scan base-package="com.ssdr" />
<!-- Configures the #Controller programming model -->
<mvc:annotation-driven />
<!-- Forwards requests to the "/" resource to the "index" view -->
<!--
<mvc:view-controller path="/" view-name="index" />
-->
<!-- Make webapp/resources directory accessible to web app -->
<mvc:resources location="/resources/" mapping="/resources/**" />
<!-- Resolves view names to protected .jsp resources within the context root directory -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
<bean class="org.springframework.web.client.RestTemplate">
<property name="messageConverters">
<list>
<bean
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="supportedMediaTypes" value="application/json" />
<property name="objectMapper">
<bean class="com.fasterxml.jackson.databind.ObjectMapper">
<property name="annotationIntrospector">
<bean
class="com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector" />
</property>
</bean>
</property>
</bean>
</list>
</property>
</bean>
<!-- <bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
<property name="mediaTypes">
<map>
<entry key="html" value="text/html"/>
<entry key="json" value="application/json"/>
</map>
</property>
<property name="viewResolvers">
<list>
<bean class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
</list>
</property>
<property name="defaultViews">
<list>
<bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">
<property name="prefixJson" value="true"/>
</bean>
</list>
</property>
</bean> -->
</beans>
NOTE: I do not want to simply ignore the upper case elements.

Answer 1

The solution was to use a combination of JacksonAnnotationIntrospector and JaxbAnnotationIntrospector. In this case Jackson was needed to recognize the #JsonIgnoreProperties and #JsonInclude annotations in the request. But Jackson always threw the "Unrecognized field" errors. JAXB could read the response with the uppercase fields but would not recognize the annotations on the request.
To use both introspectors the following code was added to the service class:
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
MappingJackson2HttpMessageConverter jaxMsgConverter = new MappingJackson2HttpMessageConverter();
ObjectMapper objMapper = new ObjectMapper();
/*
* Jackson introspector needed for #JsonIgnoreProperties and #JsonInclude annotations
* JAXB introspector is needed to handle the uppercase element names in the response
*/
AnnotationIntrospector primary = new JacksonAnnotationIntrospector();
AnnotationIntrospector secondary = new JaxbAnnotationIntrospector(TypeFactory.defaultInstance());
AnnotationIntrospector pair = AnnotationIntrospector.pair(primary, secondary);
objMapper.setAnnotationIntrospector(pair);
jaxMsgConverter.setObjectMapper(objMapper);
messageConverters.add(jaxMsgConverter);
SSDRResponse resp = null;
RestTemplate restTemplate = new RestTemplate();
// Set message converter with Jackson and JAXB introspectors in RestTemplate
restTemplate.setMessageConverters(messageConverters);
HttpEntity<SSDRRequest> httpRequest = new HttpEntity<SSDRRequest>(req, createHeaders());
resp = restTemplate.postForObject(SERVICE_URI, httpRequest, SSDRResponse.class);
To use only the JAXB introspector:
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
MappingJackson2HttpMessageConverter jaxMsgConverter = new MappingJackson2HttpMessageConverter();
ObjectMapper jaxMapper = new ObjectMapper();
AnnotationIntrospector introspector = new JaxbAnnotationIntrospector(TypeFactory.defaultInstance());
jaxMapper.setAnnotationIntrospector(introspector);
jaxMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); // ignore unknown properties
jaxMsgConverter.setObjectMapper(jaxMapper);
messageConverters.add(jaxMsgConverter);

Answer 2

My spring boot configuration (ready to use):
#Configuration
#EnableWebMvc
#EnableAutoConfiguration
#ComponentScan(basePackages = {"path.to.your.package"})
public class WebMvcConfig extends WebMvcConfigurerAdapter {
#Bean
public ObjectMapper objectMapper() {
ObjectMapper jacksonMapper = new ObjectMapper();
AnnotationIntrospector primary = new JacksonAnnotationIntrospector();
AnnotationIntrospector secondary = new JaxbAnnotationIntrospector(TypeFactory.defaultInstance());
AnnotationIntrospector pair = AnnotationIntrospector.pair(primary, secondary);
jacksonMapper.setAnnotationIntrospector(pair);
jacksonMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
return jacksonMapper;
}
#Bean
public RestTemplate getRestTemplate() {
List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
MappingJackson2HttpMessageConverter jaxMsgConverter = new MappingJackson2HttpMessageConverter();
ObjectMapper objectMapper = objectMapper();
jaxMsgConverter.setObjectMapper(objectMapper);
messageConverters.add(jaxMsgConverter);
HttpClientBuilder builder = HttpClientBuilder.create();
HttpClient httpClient = builder.build();
HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory(httpClient);
RestTemplate template = new RestTemplate(new BufferingClientHttpRequestFactory(factory));
template.setMessageConverters(messageConverters);
return template;
}
}