I generated the project from Spring Initialzr online.
Below is my Controller and the method i am using. Here breedService.getAllDogsByBreedName(breed) will provide me with all the dogs coming under that particular entered "breed". However the returned object "breed1" is JSON and is displayed in the browser with all the details of the dogs.
I want to represent it in an html or jsp view to make it presentable. Is there any way that i can pass the JSON results for "Labrador" obtained in the attached pic below to an html or jsp? or if there is any method to acheive this Please be considerate to help me, Thank you.
#RestController
#RequestMapping("/Disney")
public class BreedInfoController {
#RequestMapping(value = "/{breed}", method = RequestMethod.GET, produces = { "application/json" })
#ResponseBody
public BreedMaster getBreedNameofDogs(#PathVariable("breed") String breed) {
Breed breed1 = breedService.getAllDogsByBreedName(breed);
return breed1;
}
}
I've integrated Katharsis with spring-boot (MVC + Security) and I'm realy happy about it.
#SpringBootApplication
#Import(KatharsisConfigV2.class)
#Configuration
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
I began to setup security with an extra spring mvc controller to handle login and logout methods.
But with a RequestBody annotated parameters to convert json to java object, I've got a 400 response telling me required body is missing.
#RequestMapping(value = "/auth/signup", method = RequestMethod.POST)
public #ResponseBody AuthenticationResponse signup(
#RequestBody AuthenticationRequest authenticationRequest) {
...
}
When I remove the import for Katharsis configuration, everything goes fine.
#SpringBootApplication
//#Import(KatharsisConfigV2.class)
#Configuration
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
How could I tweak my project configuration to allow basics spring controllers to accept standard JSON?
Thanks in advance
What is the exact message in the "detail" field of the response? Katharsis-Spring provides decent error details. That should provide you a better idea of exactly what's wrong.
Remember that POST bodies in JSON API will differ from how they look in regular Spring, e.g. there needs to be a "data" field in your payload.
You may also need to configure Katharsis in your application.properties file. Katharsis can't process requests unless it's configured properly.
Hope this helps.
Hi I have a requirement to dynamically ignore entity fields in spring data rest response [I know they can be done in a static way by using #JsonIgnore annotation] ideally based on a spring security Role .The role part is still manageable but how to dynamically ignore fields in the json response is a challenge.
After some analysis and the docs I think jackson is the way to go as spring data rest does provide jackson customization via jackson modules and mixins http://docs.spring.io/spring-data/rest/docs/current/reference/html/#customizing-sdr.custom-jackson-deserialization .
So I think in jackson api it could be done via #jsonFilter and then suppling the same when the ObjectMapper write the object [more details here http://www.cowtowncoder.com/blog/archives/2011/09/entry_461.html] .
But I am not sure how this could be wired up with Spring data rest (basically the part where I acan inject the filterprovider into spring data rest objectmapper).Let me know if anyone has tried this or someone from the Spring data team has insights .
Will post an answer myself If I am able to achieve the same.
UPDATE
So I figured out that the way to implement custom filtering is through the jackson BeanSerializerModifier .Got great help from #cowtowncoder on twitter .Also helpful reference or holy grails for filtering with jackson http://www.cowtowncoder.com/blog/archives/2011/02/entry_443.html
So yes finally I was able to solve this .The trick here is to use a custom BeanSerializerModifier and register it via a Custom Module [which is the custom hook available to customize spring data rest jackson serialization],something like
setSerializerModifier( new CustomSerializerModifier()).build()));
now you can customize our BeanSerializerModifier by overriding the method changeProperties to apply your custom filter ,which basically includes and excludes BeanPropertyWriter based on your logic .sample below
List<BeanPropertyWriter> included = Lists.newArrayList();
for (BeanPropertyWriter property : beanProperties)
if (!filter.contains(property.getName()))
included.add(property);
this way you can include any logic per class or otherwise and filter properties form response in a custom manner.Hope It Helps
Also have updated my code on github do look at https://github.com/gauravbrills/SpringPlayground
This example shows how to implement a dynamic JSON transformation (filtering) in a Spring Boot REST controller. It is using AOP controller advice to change controller method output in runtime. Code on github: https://github.com/andreygrigoriev/jsonfilter
AOP Advice
#ControllerAdvice
#SuppressWarnings("unused")
public class FilterAdvice implements ResponseBodyAdvice<Object> {
#Override
public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
String fields = ((ServletServerHttpRequest) request).getServletRequest().getParameter("fields");
return new FilterMappingJacksonValue<>(body, StringUtils.isEmpty(fields) ? new String[] {} : fields.split(","));
}
#Override
public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
return true;
}
}
FilterMappingJacksonValue
public class FilterMappingJacksonValue<T> extends MappingJacksonValue {
public FilterMappingJacksonValue(final T value, final String... filters) {
super(value);
setFilters(new SimpleFilterProvider().addFilter("dynamicFilter",
filters.length > 0 ? SimpleBeanPropertyFilter.filterOutAllExcept(filters) : SimpleBeanPropertyFilter.serializeAll()));
}
}
Simple DTO
#Data
#AllArgsConstructor
#JsonFilter("dynamicFilter")
public class Book {
String name;
String author;
}
BookController
#RestController
#SuppressWarnings("unused")
public class BookController {
#GetMapping("/books")
public List<Book> books() {
List<Book> books = new ArrayList<>();
books.add(new Book("Don Quixote", "Miguel de Cervantes"));
books.add(new Book("One Hundred Years of Solitude", "Gabriel Garcia Marquez"));
return books;
}
}
Suppose I have two sets of controllers in Spring:
/jsonapi1/*
/jsonapi2/*
both of which return objects that are to be interpretted as JSON text.
I'd like some kind of filter to wrap the responses from one set of these controllers so that:
the original response is contained within another object.
For example, if /jsonapi1/count returns:
{"num_humans":123, "num_androids":456}
then the response should be wrapped and returned as follows:
{ "status":0,
"content":{"num_humans":123, "num_androids":456}
}
if an exception happens in the controller, then filter should catch the exception and report it as follows
{ "status":5,
"content":"Something terrible happened"
}
The responses from the other controllers are returned unchanged.
We're currently customizing a MappingJackson2HttpMessageConverter passed to WebMvcConfigurerAdapter.configureMessageConverters in order to perform the above tasks. Works great except that it doesn't seem possible for this approach to be selective about the URLs (or controller classes) it applies to.
Is it possible to apply these kinds of wrappers to individual controller classes or URLs?
Update: Servlet filters look like a solution. Is it possible chose which filter gets applied to which controller methods, or which URLs?
I was struggling on this for multiple days. The solution by #Misha didn't work for me. I was able to finally get this working using ControllerAdvice and ResponseBodyAdvice.
ResponseBodyAdvice allows to inject custom transformation logic on the response returned by a controller but before it is converted to HttpResponse and committed.
This is how my controller method looks:
#RequestMapping("/global/hallOfFame")
public List<HallOfFame> getAllHallOfFame() {
return hallOfFameService.getAllHallOfFame();
}
Now i wanted to add some standard fields around the response like devmessage and usermessage. That logic goes into the ResponseAdvice:
#ControllerAdvice
public class TLResponseAdvice implements ResponseBodyAdvice<Object> {
#Override
public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
return true;
}
#Override
public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request,
ServerHttpResponse response) {
// TODO Auto-generated method stub
final RestResponse<Object> output = new RestResponse<>();
output.setData(body);
output.setDevMessage("ResponseAdviceDevMessage");
output.setHttpcode(200);
output.setStatus("Success");
output.setUserMessage("ResponseAdviceUserMessage");
return output;
}
}
The entity classes look like this:
#Setter // All lombok annotations
#Getter
#ToString
public class RestResponse<T> {
private String status;
private int httpcode;
private String devMessage;
private String userMessage;
private T data;
}
#Entity
#Data // Lombok
public class HallOfFame {
#Id
private String id;
private String name;
}
To handle exceptions, simply create another ControllerAdvice with ExceptionHandler. Use the example in this link.
Advantages of this solution:
It keeps your controllers clean. You can support any return type from your controller methods.
Your controller return type class does not need to extend some base class as required by the AOP approach.
You do not need to hack your way through Spring filters by using HttpServletResponseWrappers. They come up with a performance penalty.
EDIT - 17th September 2019
To handle exceptions use #ExceptionHandler. Refer code below.
#ExceptionHandler(Exception.class)
#ResponseBody
public MyResponseEntity<Object> handleControllerException(HttpServletRequest request, Throwable ex) {
// default value
int httpCode = HttpStatus.INTERNAL_SERVER_ERROR.value();
if(ex instanceof ResourceNotFoundException) {
httpCode = HttpStatus.NOT_FOUND.value();
}
...
}
The way I understand your question, you have exactly three choices.
Option #1
Manually wrap your objects in simple SuccessResponse, ErrorResponse, SomethingSortOfWrongResponse, etc. objects that have the fields you require. At this point, you have per-request flexibility, changing the fields on one of the response wrappers is trivial, and the only true drawback is code repetition if many of the controller's request methods can and should be grouped together.
Option #2
As you mentioned, and filter could be designed to do the dirty work, but be wary that Spring filters will NOT give you access to request or response data. Here's an example of what it might look like:
#Component
public class ResponseWrappingFilter extends GenericFilterBean {
#Override
public void doFilter(
ServletRequest request,
ServletResponse response,
FilterChain chain) {
// Perform the rest of the chain, populating the response.
chain.doFilter(request, response);
// No way to read the body from the response here. getBody() doesn't exist.
response.setBody(new ResponseWrapper(response.getStatus(), response.getBody());
}
}
If you find a way to set the body in that filter, then yes, you could easily wrap it up. Otherwise, this option is a dead end.
Option #3
A-ha. So you got this far. Code duplication is not an option, but you insist on wrapping responses from your controller methods. I'd like to introduce the true solution - aspect-oriented programming (AOP), which Spring supports fondly.
If you're not familiar with AOP, the premise is as follows: you define an expression that matches (like a regular expression matches) points in the code. These points are called join points, while the expressions that match them are called pointcuts. You can then opt to execute additional, arbitrary code, called advice, when any pointcut or combination of pointcuts are matched. An object that defines pointcuts and advice is called an aspect.
It's great for expressing yourself more fluently in Java. The only drawback is weaker static type checking. Without further ado, here's your response-wrapping in aspect-oriented programming:
#Aspect
#Component
public class ResponseWrappingAspect {
#Pointcut("within(#org.springframework.stereotype.Controller *)")
public void anyControllerPointcut() {}
#Pointcut("execution(* *(..))")
public void anyMethodPointcut() {}
#AfterReturning(
value = "anyControllerPointcut() && anyMethodPointcut()",
returning = "response")
public Object wrapResponse(Object response) {
// Do whatever logic needs to be done to wrap it correctly.
return new ResponseWrapper(response);
}
#AfterThrowing(
value = "anyControllerPointcut() && anyMethodPointcut()",
throwing = "cause")
public Object wrapException(Exception cause) {
// Do whatever logic needs to be done to wrap it correctly.
return new ErrorResponseWrapper(cause);
}
}
The final result will be the non-repeating response wrapping that you seek. If you only want some or one controller receive this effect, then update the pointcut to match methods only within instances of that controller (rather than any class holding the #Controller annotation).
You'll need to include some AOP dependencies, add the AOP-enabling annotation in a configuration class, and make sure something component-scans the package this class is in.
Simplest way i manage custom responses from controllers is by utilising the Map variable.
so your code ends up looking like:
public #ResponseBody Map controllerName(...) {
Map mapA = new HashMap();
mapA.put("status", "5");
mapA.put("content", "something went south");
return mapA;
}
beauty of is is that you can configure it any thousand ways.
Currently i use for object transmition, custom exception handling and data reporting, too easy.
Hope this helps
I am also using AOP with #Around. Developed a custom annotation and using that for point cut. I am using a global Response. It has the status, Message and data which is of type List of type
List <? extends parent> dataList
( which can solve your class cast exception). All the entities extends this Parent class. This way I can set all the data into my List.
Also I am using the message key as param with the custom annotation and setting it in action.
Hope this helps.
I have a Struts2 Action Class configured via annotations. All of the "normal" methods that are annotated with #Action work fine.
However, I need to add a method into the action that returns JSON.
Here is a trimmed down version of my class (dao autowired with Spring):
#Namespace("featureClass")
// define success and input actions for class here
public class FeatureClassAction extends ActionSupport {
FeatureClassDao featureClassDao;
#Autowired
public setFeatureClassDao(FeatureClassDeao featureClassDao) {
this.featureClassDao = featureClassDao;
}
List<FeatureClass> featureClasses;
// snip normal actions
#Action("/featureClassesJSON")
#JSON
public String getFeatureClassesJSON() throws Exception {
featureClasses = featureClassDao.getAll();
return SUCCESS;
}
}
Can anyone assist? If I have to go the struts.xml route, that means moving all of my other actions (which work fine) into it.
I figured I would share the answer, since anyone else with the same problem would likely also face the silence.
I created two actions: FeatureClassAction and FeatureClassJsonAction. FeatureClassAction was annotated as such:
#ParentPackage("struts-default")
#Namespace("/featureClass")
public class FeatureClassAction extends ActionSupport {
FeatureClassJsonAction is annotated like this:
#ParentPackage("json-default")
#Namespace("/featureClass")
public class FeatureClassJsonAction extends ActionSupport {
The method in the JSON Action was annotated like this:
#Action(value="featureClassesJson", results = {
#Result(name="success", type="json")
})
public String getFeatureClassesJSON() throws Exception {
Hope it helps someone.