So I am writing a Spring(2.5( + Jersey(1.1.4.1) and trying to create a JSONConfiguration using a ContextResolver. Here is the code:
package com.rhigdon.jersey.config;
import com.sun.jersey.api.json.JSONConfiguration;
import com.sun.jersey.api.json.JSONJAXBContext;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;
import javax.xml.bind.JAXBContext;
#Provider
public final class JAXBContextResolver implements ContextResolver<JAXBContext> {
private JAXBContext context;
public JAXBContextResolver() throws Exception {
this.context = new JSONJAXBContext(JSONConfiguration.mappedJettison().build(), "com.rhigdon.core.model.");
}
public JAXBContext getContext(Class<?> aClass) {
return context;
}
}
Unfortunately my app is still returning the default mapping:
{"id":"1","question":"What is/was the
name of your first pet?"}
When I debug the application it never actually hits this code. Is this due to using the SpringServlet? Here is my Jersey Config in my web.xml:
<servlet>
<servlet-name>Jersey Spring Web Application</servlet-name>
<servlet-class>com.sun.jersey.spi.spring.container.servlet.SpringServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Spring Web Application</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
Anyone have a similar setup with JSONConfiguration working?
You need to register your provider in your spring context:
<bean class="com.company.jersey.config.JAXBContextResolver"/>
Or, if you are using annotation-based configuration, you need to annotate your provider class with #Component and include something like
<context:annotation-config />
<context:component-scan base-package="com.company.jersey" />
to your application context configuration.
I'm using jersey version 1.10 and I don't have the #Component annotation nor the bean definition, and it works without it.
Jersey REST Service
com.sun.jersey.spi.spring.container.servlet.SpringServlet
com.sun.jersey.config.property.packages
ca.gc.cbsa.ezfw.foundation.webservice
1
Related
I am struggling with this issue for days now and have no clue how to solve this. Any quick help will be grateful.
I need to convert LocalDate from JSON string which I am receiving from REST service build using apache CXF and jackson. I wrote custom ContextResolver and registered JavaTimeModule in Mapper object.
When I run the application, default constructor is called, that means it has been loaded, but getContext() method which returns ObjectMapper never gets called.
I have registered same ContextResolver in server and client side.
All dependencies are in place(jackson databind, core, annotation, datatype-jsr310).
I am able to fetch JSON response when I hit REST URI directly in browser. Issue comes when I call same URI annotated method from client code
Below is my client code.
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
#Provider //makes this bean a Provider
public class LocalDateObjectMapperContextResolver implements ContextResolver<ObjectMapper>{
private final ObjectMapper MAPPER;
public LocalDateObjectMapperContextResolver() {
MAPPER = new ObjectMapper();
MAPPER.registerModule(new JavaTimeModule());
MAPPER.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
}
#Override
public ObjectMapper getContext(Class<?> type) {
return MAPPER;
}
}
<jaxrs:client id="testclient"
serviceClass="package1.RESTService"
username="abc"
password="abc"
address="$serviceURL">
<jaxrs:features>
<bean class="org.apache.cxf.transport.common.gzip.GZIPFeature"/>
<cxf:logging/>
</jaxrs:features>
<jaxrs:providers>
<bean class="org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider"/>
<bean class="mypackage.LocalDateObjectMapperContextResolver"/>
</jaxrs:providers>
</jaxrs:client>
Same way, This contextResolver is registered on server side also under
<jaxrs:server>
.....
<jaxrs:providers>
<bean class="org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider"/>
<bean class="mypackage.LocalDateObjectMapperContextResolver"/>
</jaxrs:providers>
</jaxrs:server>
Any reason why getContext is not called?
I also tried by extending ObjectMapper and registering javaTimeModule there, but dont know how to register customObjectMapper in Jackson flow. I just put default constructor for testing, And it does get called while application startup, but then again, No results, I still get same error.
Error: No suitable constructor found for type [simple type, class java.time.LocalDate]: can not instantiate from JSON object (need to add/enable type information?)
I had exactly the same problem #peeskillet describes in question comment.
I was using Jackson dependencies from version 2 and jackson-jaxrs from version 1.
All solved when moved all dependencies to version 2.
If you are using Maven you can add following two maven dependency.
<dependency>
<groupId>com.fasterxml.jackson.jaxrs</groupId>
<artifactId>jackson-jaxrs-json-provider</artifactId>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jdk8</artifactId>
</dependency>
And Add following code snippet.
#Configuration
public class CxfConfig {
#Component
#javax.ws.rs.ext.Provider
public static class JacksonJaxbJsonProvider
extends com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider {
#Autowired
private ObjectMapper objectMapper;
#PostConstruct
public void init() {
objectMapper.registerModule(new Jdk8Module());
}
}
}
I had been working for sometime to figure out how to create a JAX Restful Service... using the guide available here - Jersey
As explained in Section 2.3.2, I had added the below dependency in Maven -
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet</artifactId>
<version>2.0</version>
</dependency>
In web.xml
<servlet>
<servlet-name>Jersey REST Service</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.classnames</param-name>
<param-value>org.glassfish.jersey.filter.LoggingFilter</param-value>
</init-param>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.hms.rs.controller.MyApp</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey REST Service</servlet-name>
<url-pattern>/services/*</url-pattern>
</servlet-mapping>
and MyApp.java
public class MyApp extends Application{
#Override
public Set<Class<?>> getClasses() {
return new HashSet<Class<?>>() {{
// Add your resources.
System.out.println("From the Myapp...");
add(Patient.class);
add(PatientController.class);
// Add LoggingFilter.
add(LoggingFilter.class);
}};
}
}
Patient.java -
#XmlRootElement(name = "Patient")
public class Patient {
private String patientFName;
private String patientLName;
private int patientAge;
private String patientSex;
private String patientParentSpouse;
private String patientQual;
private String patientOccupation;
private String patientComments;
public Patient()
{
}
Setters and Getters....
}
PatientController.java -
#Path("/ManagePatient")
public class PatientController {
#GET
#Path("/getPatient")
#Produces(MediaType.APPLICATION_XML)
public Patient printPatient() {
System.out.println("Hello.... from the PatientController");
Patient ptnt = new Patient();
ptnt.setPatientFName("FirstN");
ptnt.setPatientLName("LName");
ptnt.setPatientAge(30);
ptnt.setPatientSex("M");
ptnt.setPatientParentSpouse("ParentSpuse");
ptnt.setPatientQual("engg");
ptnt.setPatientOccupation("software");
ptnt.setPatientComments("comments here");
System.out.println("Patient = " + ptnt);
//return ptnt.toString();
return ptnt;
}
When I try to access this via browser # localhost:8080/HMS_Web/services/ManagePatient/getPatient
I am getting
javax.servlet.ServletException: org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=text/html, type=class com.hms.app.ui.beans.Patient, genericType=class com.hms.app.ui.beans.Patient.
and I also see the below warning in the logs-
WARNING: A provider com.hms.app.ui.beans.Patient registered in SERVER runtime does not implement any provider interfaces applicable in the SERVER runtime. Due to constraint configuration problems the provider com.hms.app.ui.beans.Patient will be ignored.
If Jersey 2.0 supports JAXB based xml or json support as mentioned # section "8.1.1.2. JAXB based JSON support" in the Jersey guide, I am not sure why I am receiving the Provider errors.
Could any JAX-WS expert help me understand and also provide me direction on how to resolve this situation?
Thank you in advance
you are accessing the service via browser, so your PatientController will try to render response as html, I guess this is the reason for the
javax.servlet.ServletException: org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=text/html, type=class com.hms.app.ui.beans.Patient, genericType=class com.hms.app.ui.beans.Patient.
try to comsume the service via jersey client api as following:
WebTarget webTarget = client.target("http://localhost:8080/HMS_Web/services/ManagePatient/getPatient");
Patient patient = webTarget.request(MediaType.APPLICATION_XML_TYPE).get(Patient.class);
for the warning:
WARNING: A provider com.hms.app.ui.beans.Patient registered in SERVER runtime does not implement any provider interfaces applicable in the SERVER runtime. Due to constraint configuration problems the provider com.hms.app.ui.beans.Patient will be ignored.
I think you should remove:
add(Patient.class);
in your MyApp. Patient is just a POJO, it is neither a resource nor a provider.
I am trying to use Jersey's capabilities to produce JSON from my web-service methods.
Everything worked well but then I discovered that for a list of objects JSON representation contains something like enclosing root tag. I found out that I can configure JAXB Based JSON support with JSONConfiguration.natural() to produce a desirable result. So I wrote the following
#Provider
#Produces(MediaType.APPLICATION_JSON)
public class JAXBContextResolver implements ContextResolver<JAXBContext> {
private final JAXBContext context;
private final Set<Class> types;
private final Class[] cTypes = {TrRegion.class};
public JAXBContextResolver() throws Exception {
this.types = new HashSet(Arrays.asList(cTypes));
this.context = new JSONJAXBContext(JSONConfiguration.natural().build(), cTypes);
}
#Override
public JAXBContext getContext(Class<?> objectType) {
return (types.contains(objectType)) ? context : null;
}
}
And plugged it in like this
public class WebServiceApplication extends Application {
#Override
public Set<Class<?>> getClasses()
{
Set<Class<?>> resources = new HashSet<Class<?>>();
resources.add(OrderInfrastructureResource.class);
resources.add(OrderResource.class);
resources.add(JAXBContextResolver.class);
return resources;
}
}
<servlet>
<description>JAX-RS Tools Generated - Do not modify</description>
<servlet-name>JAX-RS Servlet</servlet-name>
<servlet-class>com.sun.jersey.spi.spring.container.servlet.SpringServlet</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.[...].WebServiceApplication</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
But for some reason I always get
java.lang.IllegalStateException: No JAXB provider found for the following JAXB context: class com.sun.xml.bind.v2.runtime.JAXBContextImpl
at com.sun.jersey.json.impl.JSONHelper.getJaxbProvider(JSONHelper.java:106) [jersey-json-1.17.jar:1.17]
at com.sun.jersey.json.impl.JSONHelper.getJaxbProvider(JSONHelper.java:106) [jersey-json-1.17.jar:1.17]
at com.sun.jersey.json.impl.DefaultJaxbXmlDocumentStructure.getXmlDocumentStructure(DefaultJaxbXmlDocumentStructure.java:76) [jersey-json-1.17.jar:1.17]
at com.sun.jersey.json.impl.writer.Stax2JacksonWriter.<init>(Stax2JacksonWriter.java:169) [jersey-json-1.17.jar:1.17]
at com.sun.jersey.json.impl.Stax2JsonFactory.createWriter(Stax2JsonFactory.java:105) [jersey-json-1.17.jar:1.17]
at com.sun.jersey.json.impl.provider.entity.JSONListElementProvider.writeList(JSONListElementProvider.java:133) [jersey-json-1.17.jar:1.17]
Can someone tell me why?
When I change the line
this.context = new JSONJAXBContext(JSONConfiguration.natural().build(), cTypes);
to
this.context = new JSONJAXBContext(JSONConfiguration.mapped().build(), cTypes);
it begins to work but gives enclosing root tag(well it is the same as not specifying any ContextResolver). Strange.(Strange meaning, that the difference is only in mapping type I provide).
I try to run my app on Jboss 7.1.1 with Restesy disabled(I have removed lines <extension module="org.jboss.as.jaxrs"/> and <subsystem xmlns="urn:jboss:domain:jaxrs:1.0"/> from my standalone.xml file). Also I use com.sun.jersey.spi.spring.container.servlet.SpringServlet as Jersey servlet.
Please, tell me what am I missing.
What could be the problem?
Apparently I was missing jaxb-impl library for my application so I just added jBoss' com.sun.xml.bind module in my jboss-deployment-structure file as following:
<dependencies>
<module name="com.sun.xml.bind" />
<module name="org.codehaus.jackson.jackson-core-asl" />
<module name="org.codehaus.jackson.jackson-jaxrs" />
<module name="org.codehaus.jackson.jackson-mapper-asl" />
<module name="org.codehaus.jackson.jackson-xc" />
</dependencies>
According to http://wiki.fasterxml.com/JacksonFAQDateHandling, “DateTime can be automatically serialized/deserialized similar to how java.util.Date is handled.” However, I am not able to accomplish this automatic functionality. There are StackOverflow discussions related to this topic yet most involve a code-based solution, but based upon the quote above I should be able to accomplish this via simple configuration.
Per http://wiki.fasterxml.com/JacksonFAQDateHandling I have my configuration set so that writing dates as timestamps is false. The result is that java.util.Date types are serialized to ISO 8601 format, but org.joda.time.DateTime types are serialized to a long object representation.
My environment is this:
Jackson 2.1
Joda time 2.1
Spring 3.2
Java 1.6
My Spring configuration for the jsonMapper bean is
#Bean
public ObjectMapper jsonMapper() {
ObjectMapper objectMapper = new ObjectMapper();
//Fully qualified path shows I am using latest enum
ObjectMapper.configure(com.fasterxml.jackson.databind.SerializationFeature.
WRITE_DATES_AS_TIMESTAMPS , false);
return objectMapper;
}
My test code snippet is this
Date d = new Date();
DateTime dt = new DateTime(d); //Joda time
Map<String, Object> link = new LinkedHashMap<String, Object>();
link.put("date", d);
link.put("createdDateTime", dt);
The resulting snippet of JSON output is this:
{"date":"2012-12-24T21:20:47.668+0000"}
{"createdDateTime": {"year":2012,"dayOfMonth":24,"dayOfWeek":1,"era":1,"dayOfYear":359,"centuryOfEra":20,"yearOfEra":2012,"yearOfCentury":12,"weekyear":2012,"monthOfYear":12 *... remainder snipped for brevity*}}
My expectation is that the DateTime object should matche that of the Date object based upon the configuration. What am I doing wrong, or what am I misunderstanding? Am I reading too much into the word automatically from the Jackson documentation and the fact that a string representation was produced, albeit not ISO 8601, is producing the advertised automatic functionality?
I was able to get the answer to this from the Jackson user mailing list, and wanted to share with you since it is a newbie issue. From reading the Jackson Date FAQ, I did not realize that extra dependencies and registration are required, but that is the case. It is documented at the git hub project page here https://github.com/FasterXML/jackson-datatype-joda
Essentially, I had to add another dependency to a Jackson jar specific to the Joda data type, and then I had to register the use of that module on the object mapper. The code snippets are below.
For my Jackson Joda data type Maven dependency setup I used this:
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-joda</artifactId>
<version>${jackson.version}</version>
</dependency>
To register the Joda serialization/deserialization feature I used this:
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JodaModule());
objectMapper.configure(com.fasterxml.jackson.databind.SerializationFeature.
WRITE_DATES_AS_TIMESTAMPS , false);
Using Spring Boot.
Add to your Maven configuration...
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-joda</artifactId>
<version>2.7.5</version>
</dependency>
Then to your WebConfiguration...
#Configuration
public class WebConfiguration extends WebMvcConfigurerAdapter
{
public void configureMessageConverters(List<HttpMessageConverter<?>> converters)
{
final MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
final ObjectMapper objectMapper = new ObjectMapper();
//configure Joda serialization
objectMapper.registerModule(new JodaModule());
objectMapper.configure(
com.fasterxml.jackson.databind.SerializationFeature.
WRITE_DATES_AS_TIMESTAMPS , false);
// Other options such as how to deal with nulls or identing...
objectMapper.setSerializationInclusion (
JsonInclude.Include.NON_NULL);
objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
converter.setObjectMapper(objectMapper);
converters.add(converter);
super.configureMessageConverters(converters);
}
}
In Spring Boot the configuration is even simpler. You just declare Maven dependency
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-joda</artifactId>
</dependency>
and then add configuration parameter to your application.yml/properties file:
spring.jackson.serialization.write-dates-as-timestamps: false
I thought I'd post an updated working example using:
Spring 4.2.0.RELEASE, Jackson 2.6.1, Joda 2.8.2
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
">
<!-- DispatcherServlet Context: defines this servlet's request-processing
infrastructure -->
<!-- Enables the Spring MVC #Controller programming model -->
<annotation-driven>
<message-converters>
<beans:bean
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<beans:property name="objectMapper" ref="objectMapper" />
</beans:bean>
</message-converters>
</annotation-driven>
<!-- Handles HTTP GET requests for /resources/** by efficiently serving
up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by #Controllers to .jsp resources
in the /WEB-INF/views directory -->
<beans:bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<beans:bean id="objectMapper"
class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
<beans:property name="featuresToDisable">
<beans:array>
<util:constant
static-field="com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS" />
</beans:array>
</beans:property>
<beans:property name="modulesToInstall"
value="com.fasterxml.jackson.datatype.joda.JodaModule" />
</beans:bean>
<beans:bean id="localeResolver"
class="org.springframework.web.servlet.i18n.SessionLocaleResolver">
<beans:property name="defaultLocale" value="en" />
</beans:bean>
<!-- Configure the Message Locale Resources -->
<beans:bean id="messageSource"
class="org.springframework.context.support.ResourceBundleMessageSource">
<beans:property name="basename" value="errors" />
</beans:bean>
<beans:bean id="versionSource"
class="org.springframework.context.support.ResourceBundleMessageSource">
<beans:property name="basename" value="version" />
</beans:bean>
<!-- DataSource -->
<beans:bean id="dataSource"
class="org.springframework.jndi.JndiObjectFactoryBean">
<beans:property name="jndiName" value="java:comp/env/jdbc/TestDB" />
</beans:bean>
<!-- POJO: Configure the DAO Implementation -->
<beans:bean id="publicationsDAO"
class="com.test.api.publication.PublicationsDAOJdbcImpl">
<beans:property name="dataSource" ref="dataSource" />
</beans:bean>
<!-- Things to auto-load -->
<context:component-scan base-package="com.test.api" />
<context:component-scan base-package="com.test.rest" />
</beans:beans>
API Code
package com.test.api.publication;
import java.util.Map;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonRootName;
#JsonRootName("event")
#JsonIgnoreProperties(ignoreUnknown=true)
public class Publication {
private Map<String, Object> tokens;
private String href;
private String policy_path;
#JsonProperty("tokens")
public Map<String, Object> getTokens() {
return tokens;
}
#JsonProperty("tokens")
public void setTokens(Map<String, Object> tokens) {
this.tokens = tokens;
}
#JsonProperty("href")
public String getHref() {
return href;
}
#JsonProperty("href")
public void setHref(String href) {
this.href = href;
}
#JsonProperty("policyPath")
public String getPolicyPath() {
return policy_path;
}
#JsonProperty("policyPath")
public void setPolicyPath(String policy_path) {
this.policy_path = policy_path;
}
}
package com.test.api.publication;
import javax.sql.DataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class PublicationsDAOJdbcImpl implements PublicationsDAO{
static final Logger logger = LoggerFactory.getLogger(PublicationsDAOJdbcImpl.class.getName());
private DataSource _dataSource;
#Override
public void setDataSource(DataSource ds) {
// TODO Auto-generated method stub
}
#Override
public void close() {
// TODO Auto-generated method stub
}
#Override
public Publication getPublication(String policyPath) {
Publication ret = new Publication();
//TODO: do something
return ret;
}
}
package com.test.rest.publication;
import java.util.HashMap;
import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import com.test.api.publication.Publication;
import com.test.api.publication.PublicationsDAO;
import com.test.rest.error.UnknownResourceException;
#RestController
#RequestMapping("/pub")
public class PublicationController {
private static final Logger logger = LoggerFactory.getLogger(PublicationController.class);
#Autowired
#Qualifier("publicationsDAO")
private PublicationsDAO publicationsDAO;
/**********************************************************************************************************************
*
* #param policyPath
* #return
* #throws UnknownResourceException
*/
#RequestMapping(value = "/{policyPath}", method = RequestMethod.GET)
public Publication getByPolicyPath(#PathVariable String policyPath) throws UnknownResourceException{
logger.debug("policyPath=" + policyPath);
Publication ret = publicationsDAO.getPublication(policyPath);
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("TEST1", null);
map.put("TEST2", new Integer(101));
map.put("TEST3", "QuinnZilla");
map.put("TEST4", new DateTime());
ret.setTokens(map);
return ret;
}
}
And I get the output result
{
"tokens": {
"TEST2": 101,
"TEST3": "QuinnZilla",
"TEST4": "2015-10-06T16:59:35.120Z",
"TEST1": null
},
"href": null,
"policyPath": null
}
I'm not sure whether this is a misconfiguration on my part, a misunderstanding of what can be accomplished via #ModelAttribute and automatic JSON content conversion, or a bug in either Spring or Jackson. If it turns out to be the latter, of course, I'll file an issue with the appropriate folks.
I've encountered a problem with adding a #ModelAttribute to a controller's handler method. The intent of the method is to expose a bean that's been populated from a form or previous submission, but I can reproduce the issue without actually submitting data into the bean.
I'm using the Spring mvc-showcase sample. It's currently using Spring 3.1, but I first encountered, and am able to reproduce, this issue on my 3.0.5 setup. The mvc-showcase sample uses a pretty standard servlet-context.xml:
servlet-context.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xsi:schemaLocation="
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Enables the Spring MVC #Controller programming model -->
<annotation-driven conversion-service="conversionService">
<argument-resolvers>
<beans:bean class="org.springframework.samples.mvc.data.custom.CustomArgumentResolver"/>
</argument-resolvers>
</annotation-driven>
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources/ directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by #Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<!-- Imports user-defined #Controller beans that process client requests -->
<beans:import resource="controllers.xml" />
<!-- Only needed because we install custom converters to support the examples in the org.springframewok.samples.mvc.convert package -->
<beans:bean id="conversionService" class="org.springframework.samples.mvc.convert.CustomConversionServiceFactoryBean" />
<!-- Only needed because we require fileupload in the org.springframework.samples.mvc.fileupload package -->
<beans:bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />
</beans:beans>
The controllers.xml referenced in the file simply sets up the relevant component-scan and view-controller for the root path. The relevant snippet is below.
controllers.xml
<!-- Maps '/' requests to the 'home' view -->
<mvc:view-controller path="/" view-name="home"/>
<context:component-scan base-package="org.springframework.samples.mvc" />
The test bean which I am attempting to deliver is a dead-simple POJO.
TestBean.java
package org.springframework.samples.mvc.test;
public class TestBean {
private String testField = "test#example.com";
public String getTestField() {
return testField;
}
public void setTestField(String testField) {
this.testField = testField;
}
}
And finally, the controller, which is also simple.
TestController.java
package org.springframework.samples.mvc.test;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
#Controller
#RequestMapping("test/*")
public class TestController {
#ModelAttribute("testBean")
public TestBean getTestBean() {
return new TestBean();
}
#RequestMapping(value = "beanOnly", method = RequestMethod.POST)
public #ResponseBody
TestBean testBean(#ModelAttribute("testBean") TestBean bean) {
return bean;
}
#RequestMapping(value = "withoutModel", method = RequestMethod.POST)
public #ResponseBody
Model testWithoutModel(Model model) {
model.addAttribute("result", "success");
return model;
}
#RequestMapping(value = "withModel", method = RequestMethod.POST)
public #ResponseBody
Model testWithModel(Model model, #ModelAttribute("testBean") TestBean bean) {
bean.setTestField("This is the new value of testField");
model.addAttribute("result", "success");
return model;
}
}
If I call the controller via the mapped path /mvc-showcase/test/beanOnly, I get a JSON representation of the bean, as expected. Calling the withoutModel handler delivers a JSON representation of the Spring Model object associated with the call. It includes the implicit #ModelAttribute from the initial declaration in the return value, but the bean is unavailable to the method. If I wish to process the results of a form submission, for example, and return a JSON response message, then I need that attribute.
The last method adds the #ModelAttribute, and this is where the trouble comes up. Calling /mvc-showcase/test/withModel causes an exception.
In my 3.0.5 installation, I get a JsonMappingException caused by a lack of serializer for FormattingConversionService. In the 3.1.0 sample, the exception is caused by lack of serializer for DefaultConversionService. I'll include the 3.1 exception here; it seems to have the same root cause, even if the path is a bit different.
3.1 org.codehaus.jackson.map.JsonMappingException
org.codehaus.jackson.map.JsonMappingException: No serializer found for class org.springframework.format.support.DefaultFormattingConversionService and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: org.springframework.validation.support.BindingAwareModelMap["org.springframework.validation.BindingResult.testBean"]->org.springframework.validation.BeanPropertyBindingResult["propertyAccessor"]->org.springframework.beans.BeanWrapperImpl["conversionService"])
at org.codehaus.jackson.map.ser.StdSerializerProvider$1.failForEmpty(StdSerializerProvider.java:89)
at org.codehaus.jackson.map.ser.StdSerializerProvider$1.serialize(StdSerializerProvider.java:62)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:272)
at org.codehaus.jackson.map.ser.BeanSerializer.serializeFields(BeanSerializer.java:175)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:147)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:272)
at org.codehaus.jackson.map.ser.BeanSerializer.serializeFields(BeanSerializer.java:175)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:147)
at org.codehaus.jackson.map.ser.MapSerializer.serializeFields(MapSerializer.java:207)
at org.codehaus.jackson.map.ser.MapSerializer.serialize(MapSerializer.java:140)
at org.codehaus.jackson.map.ser.MapSerializer.serialize(MapSerializer.java:22)
at org.codehaus.jackson.map.ser.StdSerializerProvider._serializeValue(StdSerializerProvider.java:315)
at org.codehaus.jackson.map.ser.StdSerializerProvider.serializeValue(StdSerializerProvider.java:242)
at org.codehaus.jackson.map.ObjectMapper.writeValue(ObjectMapper.java:1030)
at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:153)
at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:181)
at org.springframework.web.servlet.mvc.method.annotation.support.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:121)
at org.springframework.web.servlet.mvc.method.annotation.support.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:101)
at org.springframework.web.servlet.mvc.method.annotation.support.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:81)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:64)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMethodAdapter.invokeHandlerMethod(RequestMappingHandlerMethodAdapter.java:505)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMethodAdapter.handleInternal(RequestMappingHandlerMethodAdapter.java:468)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at
...
So, is there some configuration I am missing that should allow the Jackson converter to properly handle a response derived from a handler with #ModelAttribute in the method signature? If not, any thoughts as to whether this is more likely a Spring bug or a Jackson bug? I'm leaning toward Spring, at this point.
It looks like a Spring config problem, when serializing to JSON the DefaultFormattingConversionService is empty and Jackson (by default) will throw an exception if a bean is empty see FAIL_ON_EMPTY_BEANS in the features documentation. But I am not clear why the bean is empty.
It should work if you set FAIL_ON_EMPTY_BEANS to false, but still doesn't really explain why it is happening in the first place.
DefaultFormattingConversionService is new to 3.1 - it extends the FormattingConversionService which explains the different exceptions between 3.0.5 and 3.1.
I do not think it is a Jackson problem, although a new version of Jackson (1.8.0) was released only 3 days ago so you could try that also.
I will try to reproduce this locally.