After extensive investigations, I wanted to share the problem and the resolution.
Problem
I have a RestController that works well, as long as I'm in charge of converting the JSON message. The moment I try to use an HttpMessageConverter to make the conversion more elegant, the client will start receiving HTTP 406.
So this works:
#RequestMapping(value = "/objects", method = RequestMethod.GET)
public Map<String, Object>[] getObjects(#RequestBody Object jsonQuery) {
MyQuery query = new MyConverter().convert(jsonQuery);
// do something with query
}
But, when I configure the converter, like this:
#Configuration
#EnableWebMvc
#ComponentScan
public class WebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> httpMessageConverters) {
httpMessageConverters.add(new QueryMessageConverter(new MediaType("application", "json")));
}
}
This causes HTTP 406:
#RequestMapping(value = "/objects", method = RequestMethod.GET)
public Map<String, Object>[] getObjects(#RequestBody Query Query) {
// do something with query
}
My pom.xml only refers spring-boot, and doesn't mention jackson at all.
Solution
See below
The solution is really very simple, and it is to register the jackson handler explicitly:
#Configuration
#EnableWebMvc
#ComponentScan
public class WebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> httpMessageConverters) {
httpMessageConverters.add(new QueryMessageConverter(new MediaType("application", "json")));
httpMessageConverters.add(new MappingJackson2HttpMessageConverter());
}
}
Related
When you test your code, you send a message to rabbit-mq. How do you get the message back when the test is over?
public interface RabbitProducer {
String OUTPUT = "rabbitmq_producer_channel";
#Output(OUTPUT)
MessageChannel output();
}
public class SysGroupServiceImpl {
#Autowired
private RabbitProducer rabbitProducer;
#Override
public Result remove(Collection<? extends Serializable> idList) {
rabbitProducer.output().send(MessageBuilder.withPayload(idList)
.setHeader("x-delay", 5000)
.setHeader("MessageType", "GroupBatchDelete").build());
return Result.booleanResult(true);
}
}
#SpringBootTest
#Transactional
#Rollback
public class SysGroupServiceTest {
#Autowired
private SysGroupService sysGroupService;
#Test
void removeTest(){
sysGroupService.remove(Stream.of("1").collect(Collectors.toList()));
}
}
I use Spring Cloud Stream to be compatible with RabbitMQ, and all the relevant code is there.Is there a way to mock this out?I tried the following scheme, but due to X-dealy, I got this error:No exchange type x-delayed-message
<dependency>
<groupId>com.github.fridujo</groupId>
<artifactId>rabbitmq-mock</artifactId>
</dependency>
#Component
public class RabbitMqMock {
#Bean
public ConnectionFactory connectionFactory() {
return new CachingConnectionFactory(MockConnectionFactoryFactory.build());
}
}
I know little about mocks. Can mocks create an X-delay exchange?
I want to test my implementation for AttributeConverter using #DataJpaTest.
test code
#RunWith(SpringRunner.class)
#DataJpaTest
#AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
class FooRepositoryTest {
#Autowired
private FooRepository repository;
#Test
void getPojoTest(){
FooEntity fooEnity= repository.findById("foo");
FooPojo fooPojo = fooEntity.getJsonPojo()
//some assertion
}
}
Entity
#Entity
#Data
#NoArgsConstructor
public class FooEntity{
....
#Column(columnDefinition= "JSON")
#Convert(converter = FooConverter.class)
private FooPojo data;
....
}
Attribute Converter
public class FooConverter implements AttributeConverter<FooPojo, String> {
#Autowired
private ObjectMapper mapper;
#SneakyThrows
#Override
public String convertToDatabaseColumn(FooPojo attribute) {
return mapper.writeValueAsString(attribute);
}
#SneakyThrows
#Override
public FooPojo convertToEntityAttribute(String dbData) {
return mapper.readValue(dbData, FooPojo.class);
}
}
with my code above, when I run getPojoTest(), the #autowired OjbectMapper in Converter is null. When I try the same test with #SpringBootTest instead, it works just fine. I wonder is there any walk-around to use #DataJpaTest and ObjectMapper together.
A better alternative compared to creating your own ObjectMapper is adding the #AutoConfigureJson annotation:
#DataJpaTest
#AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
#AutoConfigureJson
public void FooRepositoryTest {
}
This is also what #JsonTest uses.
From Docs:
#DataJpaTest can be used if you want to test JPA applications. By
default it will configure an in-memory embedded database, scan for
#Entity classes and configure Spring Data JPA repositories. Regular
#Component beans will not be loaded into the ApplicationContext.
I'm working on a old Spring Application which contains lots of legacy code which needs to survive. Right now I'm working on a more modern approach of API usage and I've stumbled into a problem.
I've Added GSON for converting dates of different formats and front-ends (see below). But this causes a problem at runtime, the #ResponseBody objects become empty.
It all works fine in MockMVC which hooks up the config, but at runtime in Tomcat 8, it has problems. As I've been googling this for quite a while it seems that it could be a problem due to Jackson trying to parse the JSON as well.
Any idea's how I can ensure only GSON is used for JSON requests? (My requests contain only Simple Pojo's with Date, String and Long objects), but can have some nested objects.
Some code snippets:
WebConfig:
#EnableWebMvc
#Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new RestLoggingInterceptor());
}
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(new ExtendedGsonHttpMessageConverter());
}
}
ExtendedGsonHttpMessageConverter
public class ExtendedGsonHttpMessageConverter extends GsonHttpMessageConverter
{
private static final String[] DATE_FORMATS = new String[] {
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'",
"yyyy-MM-dd'T'HH:mm:ss.SSSZ",
"yyyy-MM-dd'T'HH:mmZ",
"yyyy-MM-dd'T'HH:mm:ssZ",
"yyyy-MM-dd'T'HH:mm:ss-'07:00'"
};
public ExtendedGsonHttpMessageConverter()
{
super();
super.setGson(buildGson());
}
protected static Gson buildGson() {
GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.registerTypeAdapter(Date.class, new DateDeserializer());
return gsonBuilder.create();
}
private static class DateDeserializer implements JsonDeserializer<Date> {
#Override
public Date deserialize(JsonElement jsonElement, Type typeOF,
JsonDeserializationContext context) throws JsonParseException {
for (String format : DATE_FORMATS) {
try {
return new SimpleDateFormat(format, Locale.GERMANY).parse(jsonElement.getAsString());
} catch (ParseException e) {
}
}
throw new JsonParseException("Unparseable date: \"" + jsonElement.getAsString()
+ "\". Supported formats: " + Arrays.toString(DATE_FORMATS));
}
}
}
The problem was using an interceptor which was logging the request.
Logging the request causes the requestBody to be null, so now I'll be using Springs AbstractRequestLoggingFilter as in the comments.
When you use Jackson's writerWithView any properties that don't have a #JsonView annotation on them are still serialised. However using #JsonView on a Spring MVC action seems to require #JsonView to be on every property.
If say we have the following model:
public class User {
private String username;
private String emailAddress;
public String getUsername() { return username; }
#JsonView(DetailView.class)
public String getEmailAddress() { return emailAddress; }
}
And DetailView extends BasicView, when I serialise with basic view I'd expect username to be serialised. This is what happens when we use writerWithView:
#RequestMapping(value = "/me", method = GET)
#ResponseBody
public String getMe() throws JsonProcessingException {
User user = getCurrentUser();
return objectMapper.writerWithView(BasicView.class).writeValueAsString(user);
}
However from Spring MVC 4.1 we can instead do the following:
#RequestMapping(value = "/me", method = GET)
#ResponseBody
#JsonView(BasicView.class)
public User getMe() throws JsonProcessingException {
return getCurrentUser();
}
The later causes the response to be {} rather than {username:"David"}. If we add #JsonView(BasicView.class) onto the getUsername() this works as expected.
Obviously we could go with the former or add #JsonView to everything, both of which are more verbose and error prone.
This looks a bit like MapperFeature.DEFAULT_VIEW_INCLUSION has been turned off, but explicitly enabling it doesn't seem to have worked.
Is there anyway to get around this?
MapperFeature.DEFAULT_VIEW_INCLUSION being disabled is indeed the problem, but unfortunately the Spring classes don't give an easy way to configure or replace the ObjectMapper used by the default message converters.
The neatest way I found to work around this was to extend DelegatingWebMvcConfiguration and override configureMessageConverters to populate the default converters and then overwrite the problematic MappingJackson2HttpMessageConverter:
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
import org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration;
import com.example.config.serialization.AllEncompassingFormHttpMessageConverterWithCustomObjectMapper;
import java.util.List;
#Configuration
#ComponentScan({/*...*/})
public class MyWebConfig extends DelegatingWebMvcConfiguration {
#Bean
public ObjectMapper objectMapper() {
ObjectMapper objectMapper = new ObjectMapper();
//...
return objectMapper;
}
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
super.configureMessageConverters(messageConverters);
if (messageConverters.isEmpty()) {
addDefaultHttpMessageConverters(messageConverters);
}
messageConverters.replaceAll(converter -> {
if (converter instanceof MappingJackson2HttpMessageConverter) {
return new MappingJackson2HttpMessageConverter(objectMapper());
} else if (converter instanceof AllEncompassingFormHttpMessageConverter) {
return new AllEncompassingFormHttpMessageConverterWithCustomObjectMapper(objectMapper());
}
return converter;
});
}
}
For completeness you may also want to substitute the AllEncompassingFormHttpMessageConverter, as above, with your own copy that also allows specification of an ObjectMapper. I've not included the AllEncompassingFormHttpMessageConverterWithCustomObjectMapper class here - it's a trivial copy of AllEncompassingFormHttpMessageConverter that forwards an ObjectMapper constructor parameter to the MappingJackson2HttpMessageConverter that it creates.
In a previous similar question, I asked about, how to serialise two different sets of fields using JacksonJson and Spring.
My use case is the typical Controller mapping with #ResponseBody annotation returning directly a particular object or collections of objects, that are then rendered with JacksonJson whenever the client adds application/json in the Accept header.
I had two answers, the first one suggests to return different interfaces with a different getter list, the second suggests to use Json Views.
I don't have problems to understand the first way, however, for the second, after reading the documentation on JacksonJsonViews, I don't know how to implement it with Spring.
To stay with the example, I would declare three stub classes, inside the class Views:
// View definitions:
public class Views {
public static class Public { }
public static class ExtendedPublic extends PublicView { }
public static class Internal extends ExtendedPublicView { }
}
Then I've to declare the classes mentioned:
public class PublicView { }
public class ExtendedPublicView { }
Why on earth they declare empty static classes and external empty classes, I don't know. I understand that they need a "label", but then the static members of Views would be enough. And it's not that ExtendedPublic extends Public, as it would be logical, but they are in fact totally unrelated.
And finally the bean will specify with annotation the view or list of views:
//changed other classes to String for simplicity and fixed typo
//in classname, the values are hardcoded, just for testing
public class Bean {
// Name is public
#JsonView(Views.Public.class)
String name = "just testing";
// Address semi-public
#JsonView(Views.ExtendedPublic.class)
String address = "address";
// SSN only for internal usage
#JsonView(Views.Internal.class)
String ssn = "32342342";
}
Finally in the Spring Controller, I've to think how to change the original mapping of my test bean:
#RequestMapping(value = "/bean")
#ResponseBody
public final Bean getBean() {
return new Bean();
}
It says to call:
//or, starting with 1.5, more convenient (ObjectWriter is reusable too)
objectMapper.viewWriter(ViewsPublic.class).writeValue(out, beanInstance);
So I have an ObjectMapper instance coming out of nowhere and an out which is not the servlet typical PrintWriter out = response.getWriter();, but is an instance of JsonGenerator and that can't be obtained with the new operator. So I don't know how to modify the method, here is an incomplete try:
#RequestMapping(value = "/bean")
#ResponseBody
public final Bean getBean() throws JsonGenerationException, JsonMappingException, IOException {
ObjectMapper objectMapper = new ObjectMapper();
JsonGenerator out; //how to create?
objectMapper.viewWriter(Views.Public.class).writeValue(out, new Bean());
return ??; //what should I return?
}
So I would like to know if anybody had success using JsonView with Spring and how he/she did. The whole concept seems interesting, but the documentation seems lacking, also the example code is missing.
If it's not possible I will just use interfaces extending each others. Sorry for the long question.
Based on the answers by #igbopie and #chrislovecnm, I've put together an annotation driven solution:
#Controller
public class BookService
{
#RequestMapping("/books")
#ResponseView(SummaryView.class)
public #ResponseBody List<Book> getBookSummaries() {}
#RequestMapping("/books/{bookId}")
public #ResponseBody Book getBook(#PathVariable("bookId") Long BookId) {}
}
Where SummaryView is annotated on the Book model like so:
#Data
class Book extends BaseEntity
{
#JsonView(SummaryView.class)
private String title;
#JsonView(SummaryView.class)
private String author;
private String review;
public static interface SummaryView extends BaseView {}
}
#Data
public class BaseEntity
{
#JsonView(BaseView.class)
private Long id;
}
public interface BaseView {}
A custom HandlerMethodReturnValueHandler is then wired into Spring MVC's context to detect the #ResponseView annotation, and apply the Jackson view accordingly.
I've supplied full code over on my blog.
You need to manually wire in the MappingJacksonHttpMessageConverter. In spring 3.1 you are able to use the mvc xml tags like the following:
<mvc:annotation-driven >
<mvc:message-converter>
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />
</mvc:message-converters>
</mvc:annotation-driven>
It is pretty ugly to not use spring 3.1, it will save you about 20 lines of xml. The mvc:annotation tag does ALOT.
You will need to wire in the object mapper with the correct view writer. I have noticed recently the using a #Configuration class can make complicated wiring like this a lot easier. Use a #Configuration class and create a #Bean with your MappingJacksonHttpMessageConverter, and wire the reference to that bean instead of the MappingJacksonHttpMessageConverter above.
I've manage to solve the problem this way:
Create custom abstract class to contain the json response object:
public abstract AbstractJson<E>{
#JsonView(Views.Public.class)
private E responseObject;
public E getResponseObject() {
return responseObject;
}
public void setResponseObject(E responseObject) {
this.responseObject = responseObject;
}
}
Create a class for each visibility (just to mark the response):
public class PublicJson<E> extends AbstractJson<E> {}
public class ExtendedPublicJson<E> extends AbstractJson<E> {}
public class InternalJson<E> extends AbstractJson<E> {}
Change your method declaration:
#RequestMapping(value = "/bean")
#ResponseBody
public final PublicJson<Bean> getBean() throws JsonGenerationException, JsonMappingException, IOException {
return new PublicJson(new Bean());
}
Create customs MessageConverter:
public class PublicJsonMessageConverter extends MappingJacksonHttpMessageConverter{
public PublicApiResponseMessageConverter(){
super();
org.codehaus.jackson.map.ObjectMapper objMapper=new org.codehaus.jackson.map.ObjectMapper();
objMapper.configure(SerializationConfig.Feature.DEFAULT_VIEW_INCLUSION, false);
objMapper.setSerializationConfig(objMapper.getSerializationConfig().withView(Views.Public.class));
this.setObjectMapper(objMapper);
}
public boolean canWrite(Class<?> clazz, MediaType mediaType) {
if(clazz.equals(PublicJson.class)){
return true;
}
return false;
}
}
public class ExtendedPublicJsonMessageConverter extends MappingJacksonHttpMessageConverter{
public ExtendedPublicJsonMessageConverter(){
super();
org.codehaus.jackson.map.ObjectMapper objMapper=new org.codehaus.jackson.map.ObjectMapper();
objMapper.configure(SerializationConfig.Feature.DEFAULT_VIEW_INCLUSION, false);
objMapper.setSerializationConfig(objMapper.getSerializationConfig().withView(Views.ExtendedPublic.class));
this.setObjectMapper(objMapper);
}
public boolean canWrite(Class<?> clazz, MediaType mediaType) {
if(clazz.equals(ExtendedPublicJson.class)){
return true;
}
return false;
}
}
public class InternalJsonMessageConverter extends MappingJacksonHttpMessageConverter{
public InternalJsonMessageConverter(){
super();
org.codehaus.jackson.map.ObjectMapper objMapper=new org.codehaus.jackson.map.ObjectMapper();
objMapper.configure(SerializationConfig.Feature.DEFAULT_VIEW_INCLUSION, false);
objMapper.setSerializationConfig(objMapper.getSerializationConfig().withView(Views.Internal.class));
this.setObjectMapper(objMapper);
}
public boolean canWrite(Class<?> clazz, MediaType mediaType) {
if(clazz.equals(Internal.class)){
return true;
}
return false;
}
}
Add the following to your xml:
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="PublicJsonMessageConverter"></bean>
<bean class="ExtendedPublicJsonMessageConverter"></bean>
<bean class="InternalJsonMessageConverter"></bean>
</mvc:message-converters>
</mvc:annotation-driven>
That's it! I had to update to spring 3.1 but that's all. I use the responseObject to send more info about the json call but you can override more methods of the MessageConverter to be completely transparent. I hope someday spring include an annotation for this.
Hope this helps!