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've the following code to change a property in Jackson. I'm annotating the classes with XMLRootElements and letting Jersey convert it to JSON, using jackson.
Classes are JAXB annotated.
#Provider
#Produces("application/json")
public class JacksonObjectMapper implements ContextResolver<ObjectMapper> {
private ObjectMapper objectMapper;
public JacksonObjectMapper() throws Exception {
objectMapper.configure( DeserializationConfig.Feature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
}
#Override
public ObjectMapper getContext(Class<?> type) {
return this.objectMapper;
}
}
The configuration above, works as expected if I use Jackson outside jersey (i.e: using his own function), but If I use it inside a Jersey app, the configuration options are ignored.
Is there a way to instruct Jersey to use my class to serialize / deserialize from XML to JSON?
Add this class to your javax.ws.rs.core.Application's classes list:
application.addClass(JacksonObjectMapper.class)
Is there any way that I can use Jackson JSON Views or something like it, without having to annotate the original bean class? I'm looking for some kind of runtime/dynamic configuration to let me do something similar.
My bean is an #Entity packaged in a JAR that may be shared by multiple projects. I'm trying to avoid touching and re-packaging the shared JAR because of UI changes in the consuming projects.
Ideally I'd like to do something like
jsonViewBuilder = createViewBuilder(View.class);
jsonViewBuilder.addProperty("property1");
jsonViewBuilder.addProperty("property2");
to replace
Bean {
#JsonView(View.class)
String property1;
#JsonView(View.class)
String property2;
}
Any ideas?
Underlying environment: Spring 3.0, Spring MVC and Glassfish 3.1.1.
How about using the Mix-In feature?
http://wiki.fasterxml.com/JacksonMixInAnnotations
http://www.cowtowncoder.com/blog/archives/2009/08/entry_305.html
import org.codehaus.jackson.annotate.JsonAutoDetect.Visibility;
import org.codehaus.jackson.annotate.JsonMethod;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonView;
public class JacksonFoo
{
public static void main(String[] args) throws Exception
{
ObjectMapper mapper = new ObjectMapper().setVisibility(JsonMethod.FIELD, Visibility.ANY)
.configure(SerializationConfig.Feature.DEFAULT_VIEW_INCLUSION, false);
mapper.getSerializationConfig().addMixInAnnotations(Bar.class, BarMixIn.class);
mapper.setSerializationConfig(mapper.getSerializationConfig().withView(Expose.class));
System.out.println(mapper.writeValueAsString(new Bar()));
// output: {"b":"B"}
}
}
class Bar
{
String a = "A";
String b = "B";
}
abstract class BarMixIn
{
#JsonView(Expose.class)
String b;
}
// Used only as JsonView marker.
// Could use any existing class, like Object, instead.
class Expose {}
I'm throwing an exception MyCustomException from my application. (EJB Layer)
I've an exception mapper in web service layer which looks like following -
package net.webservices;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.Provider;
import net.common.MyCustomException;
#Provider
public class EJBExceptionMapper implements
ExceptionMapper<net.common.MyCustomException> {
public Response toResponse(MyCustomException exception) {
return Response.status(Response.Status.BAD_REQUEST).build();
}
}
I've registered my mapper in web.xml of the web service layer as following -
<context-param>
<param-name>resteasy.providers</param-name>
<param-value>net.webservices.EJBExceptionMapper</param-value>
</context-param>
The EJBExceptionMapper is not catching the MyCustomException. But instead its being caught by the catch block of the web service implementation.
What could be the problem?
Note: I don't want to register my ExceptionMapper manually using getProviderFactory().addExceptionMapper()
I don't know why your solution doesn't work (but I've never used RESTeasy, only Jersey). In any case, it would probably be simpler to extend WebApplicationException. That way, you don't have to register a provider:
public class MyCustomException extends WebApplicationException {
public MyCustomException() {
super(Response.status(Response.Status.BAD_REQUEST).build());
}
}
You need to throw exception (of type MyCustomException ) in the catch block and add a "Throws MyCustomException" to the method signature
While developing REST services using Spring MVC, I would like render JSON 'pretty printed' in development but normal (reduced whitespace) in production.
If you are using Spring Boot 1.2 or later the simple solution is to add
spring.jackson.serialization.INDENT_OUTPUT=true
to the application.properties file. This assumes that you are using Jackson for serialization.
If you are using an earlier version of Spring Boot then you can add
http.mappers.json-pretty-print=true
This solution still works with Spring Boot 1.2 but it is deprecated and will eventually be removed entirely. You will get a deprecation warning in the log at startup time.
(tested using spring-boot-starter-web)
I had an answer when I posted this question, but I thought I'd post it anyway in case there are better alternative solutions. Here was my experience:
First thing's first. The MappingJacksonHttpMessageConverter expects you to inject a Jackson ObjectMapper instance and perform Jackson configuration on that instance (and not through a Spring class).
I thought it would be as easy as doing this:
Create an ObjectMapperFactoryBean implementation that allows me to customize the ObjectMapper instance that can be injected into the MappingJacksonHttpMessageConverter. For example:
<bean id="jacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
<property name="objectMapper">
<bean class="com.foo.my.ObjectMapperFactoryBean">
<property name="prettyPrint" value="${json.prettyPrint}"/>
</bean>
</property>
</bean>
And then, in my ObjectMapperFactoryBean implementation, I could do this (as has been documented as a solution elsewhere on SO):
ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationConfig.Feature.INDENT_OUTPUT, isPrettyPrint());
return mapper;
But it didn't work. And trying to figure out why is a nightmare. It is a major test of patience to figure Jackson out. Looking at its source code only confuses you further as it uses outdated and obtuse forms of configuration (integer bitmasks for turning on/off features? Are you kidding me?)
I essentially had to re-write Spring's MappingJacksonHttpMessageConverter from scratch, and override its writeInternal implementation to be the following:
#Override
protected void writeInternal(Object o, HttpOutputMessage outputMessage)
throws IOException, HttpMessageNotWritableException {
JsonEncoding encoding = getEncoding(outputMessage.getHeaders().getContentType());
JsonGenerator jsonGenerator =
getObjectMapper().getJsonFactory().createJsonGenerator(outputMessage.getBody(), encoding);
try {
if (this.prefixJson) {
jsonGenerator.writeRaw("{} && ");
}
if (isPrettyPrint()) {
jsonGenerator.useDefaultPrettyPrinter();
}
getObjectMapper().writeValue(jsonGenerator, o);
}
catch (JsonGenerationException ex) {
throw new HttpMessageNotWritableException("Could not write JSON: " + ex.getMessage(), ex);
}
}
The only thing I added to the existing implementation is the following block:
if (isPrettyPrint()) {
jsonGenerator.useDefaultPrettyPrinter();
}
isPrettyPrint() is just a JavaBeans compatible getter w/ matching setter that I added to my MappingJacksonHttpMessageConverter subclass.
Only after jumping through these hoops was I able to turn on or off pretty printing based on my ${json.prettyPrint} value (that is set as a property depending on how the app is deployed).
I hope this helps someone out in the future!
When you are using Jackson 2.0.0, you can do it in a way Les wanted to.
I currently use RC3 and the configuration seems to be working as expected.
ObjectMapper jacksonMapper = new ObjectMapper();
jacksonMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
translates
{"foo":"foo","bar":{"field1":"field1","field2":"field2"}}
into
{
"foo" : "foo",
"bar" : {
"field1" : "field1",
"field2" : "field2"
}
}
Might I suggest this approach, it is valid with Spring 4.0.x and possibly older versions.
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import java.util.List;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
#Configuration
#EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurerAdapter {
#Bean
public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter() {
MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
mappingJackson2HttpMessageConverter.setObjectMapper(objectMapper());
return mappingJackson2HttpMessageConverter;
}
#Bean
public ObjectMapper objectMapper() {
ObjectMapper objMapper = new ObjectMapper();
objMapper.enable(SerializationFeature.INDENT_OUTPUT);
return objMapper;
}
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
super.configureMessageConverters(converters);
converters.add(mappingJackson2HttpMessageConverter());
}
}
Thanks to Willie Wheeler for the solution: Willie Wheeler's Spring blog
How do I make Jackson pretty-print the JSON content it generates?
Here's a simple example:
Original JSON Input:
{"one":"AAA","two":["BBB","CCC"],"three":{"four":"DDD","five":["EEE","FFF"]}}
Foo.java:
import java.io.FileReader;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ObjectWriter;
public class Foo
{
public static void main(String[] args) throws Exception
{
ObjectMapper mapper = new ObjectMapper();
MyClass myObject = mapper.readValue(new FileReader("input.json"), MyClass.class);
// this is Jackson 1.x API only:
ObjectWriter writer = mapper.defaultPrettyPrintingWriter();
// ***IMPORTANT!!!*** for Jackson 2.x use the line below instead of the one above:
// ObjectWriter writer = mapper.writer().withDefaultPrettyPrinter();
System.out.println(writer.writeValueAsString(myObject));
}
}
class MyClass
{
String one;
String[] two;
MyOtherClass three;
public String getOne() {return one;}
void setOne(String one) {this.one = one;}
public String[] getTwo() {return two;}
void setTwo(String[] two) {this.two = two;}
public MyOtherClass getThree() {return three;}
void setThree(MyOtherClass three) {this.three = three;}
}
class MyOtherClass
{
String four;
String[] five;
public String getFour() {return four;}
void setFour(String four) {this.four = four;}
public String[] getFive() {return five;}
void setFive(String[] five) {this.five = five;}
}
Output:
{
"one" : "AAA",
"two" : [ "BBB", "CCC" ],
"three" : {
"four" : "DDD",
"five" : [ "EEE", "FFF" ]
}
}
If this approach doesn't exactly fit your needs, if you search the API docs v1.8.1 for "pretty", it'll turn up the relevant components available. If you use API version 2.x then look instead at the newer API 2.1.0 docs.
Pretty print will be enable by adding and configure the MappingJackson2HttpMessageConverter converter. Disable prettyprint within production environment.
Message converter configuration
<mvc:annotation-driven>
<mvc:message-converters>
<bean id="jacksonHttpMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="prettyPrint" value="${json.prettyPrint}" />
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
Based on baeldung this could be a nice idea using java 8:
#Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
Optional<HttpMessageConverter<?>> converterFound;
converterFound = converters.stream().filter(c -> c instanceof AbstractJackson2HttpMessageConverter).findFirst();
if (converterFound.isPresent()) {
final AbstractJackson2HttpMessageConverter converter;
converter = (AbstractJackson2HttpMessageConverter) converterFound.get();
converter.getObjectMapper().enable(SerializationFeature.INDENT_OUTPUT);
converter.getObjectMapper().enable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
}
}
I had trouble getting the custom MappingJacksonHttpMessageConverter to work as suggested above but I was finally able to get it to work after struggling w/ the configuration. From the code stand point I did exactly what was mentioned above but I had to add the following configuration to my springapp-servlet.xml to get it to work.
I hope this helps others who are looking to implement the same.
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
<list>
<ref bean="jsonConverter" />
</list>
</property>
</bean>
<bean id="jsonConverter" class="com.xxx.xxx.xxx.common.PrettyPrintMappingJacksonHttpMessageConverter">
<property name="supportedMediaTypes" value="application/json" />
<property name="prettyPrint" value="true" />
</bean>
Jackson 2 has a nicer API, agreed, but it won't resolve this problem in a Spring MVC environment given Spring MVC uses ObjectMapper#writeValue(JsonGenerator, Object) to write objects out as JSON. This writeValue variant does not apply ObjectMapper serialization features such as INDENT_OUTPUT in either Jackson 1.x or 2.0.
I do think this is somewhat confusing. Since we use the ObjectMapper to construct JsonGenerators, I'd expect returned generators to be initialized based on configured ObjectMapper settings. I reported this as a issue against Jackson 2.0 here: https://github.com/FasterXML/jackson-databind/issues/12.
Les's suggestion of calling JsonGenerator#useDefaultPrettyPrinter based on the value of a prettyPrint flag is about the best we can do at the moment. I've gone ahead and created a Jackson2 HttpMessageConverter that does this based on the enabled status of the INDENT_OUTPUT SerializationFeature: https://gist.github.com/2423129.
I would make that a rendering issue, not the concern of the REST service.
Who's doing the rendering? Let that component format the JSON. Maybe it can be two URLs - one for production and another for development.