I'm thinking the answer here is probably no, but just in case.
I'm doing something like this:
#RequestMapping(value="data.json", params="query=overview")
public String getOverview(#RequestBody MyRequest myRequest) {
[...]
return "overview";
}
#RequestMapping(value="data.json", params="query=detail")
public String getDetail(#RequestBody MyRequest myRequest) {
[...]
return "detail";
}
and the client is POSTing JSON data, which is deserialized by Jackson on the way in and bound to the MyRequest parameter, all working nicely.
However, I don't like the query type having to be specified in the URL of the requests. What I would like is to include the query parameter in the JSON object and use that to drive the #RequestMapping. Is this possible?
If not, I guess I will implement a single mapping and have that method delegate to others based on the incoming data, but that feels like a step in the wrong direction.
What you are trying to do does not work out of the box.
If you don't like the param why don't you add the qualifier to the URL like so:
#RequestMapping("/overview/data.json")
#RequestMapping("/detail/data.json")
If you absolutely need the functionality you mention, you could implement a custom RequestMappingHandlerMapping that would do what you want by extending that class as is done here.
It's not possible if you remove the params. You have to have something distinct between the two mappings. If you are intent on getting rid of the params, best you could do is have a single method/mapping and call your services or whatever other logic you have according to what the value of query is in your MyRequest object.
#RequestMapping(value="data.json")
public String getOverviewOrDetail(#RequestBody MyRequest myRequest) {
if (myRequest.getQuery().equalsIgnoreCase("overview")) {
[...]
return "overview"
} else if(myRequest.getQuery().equalsIgnoreCase("detail")) {
[...]
return "detail"
}
}
Since both methods are unmarshalling to the same object, you don't really need two separate methods/mappings.
Related
I have the following method and I need to pass List<UUID> to this Controller method.
#GetMapping("/product/{productUuidList}")
public ResponseEntity<ApiResponse<List<ProductDTO>>> getProductList(
#RequestParam List<UUID> productUuidList) {
// code omitted
}
If I pass the list parameters by separating comma, it is ok. But, I want to pass these list parameters as Json array. When I try to pass uuid parameters in Postman as shown below, I get "productUuidList parameter is missing" error.
{
"productUuidList": ["c849bcbb-c26c-4299-9ca4-dcde56830f5f", "398ec0f8-86c8-400a-93cb-caf47c1ac92d"]
}
So, how should I properly pass uuid array to this Controller method without changing #GetMapping to #PostMapping ?
It won't work like this. Here you are sending a JSON object that looks like this java POJO :
public class MyUUIDWrapper{
private List<UUID> productUuidList;
// GETTERS/SETTERS
}
So Spring is expecting to retrieve a MyUUIDWrapper object in the RequestBody
If you change your code like this it should work :
public ResponseEntity<ApiResponse<List<ProductDTO>>> getProductList(
#RequestParam MyUUIDWrapper uuids) {
NB : If you have troubles deserializing UUIDs (I've never done it before), change List to List. Not the smartest or most beautiful solution, but you can still convert them later in your controller ;)
I am trying to intercept the object that is being returned in my controller so that I can create a flat JSON structure of the response, before Spring invokes Jackson's serialization process.
I am going to support a query parameter that allows the client to flatten the response body. Something like:
/v1/rest/employees/{employeId}/id?flat=true
The controller method looks something like:
public Employee getEmployee(...) {}
I would like to avoid implementing this flattening logic in every one of my service calls and continue to return the Employee object.
Is there some kind of facility in Spring that would allow me to A) read the query string and B) intercept the object that is being returned as the response body?
Here's one idea. There may be a better way, but this will work:
Define an extra request mapping to do the flat mapping:
#RequestMapping(path = "/endpoint", params = {"flat"})
public String getFlatThing() {
return flatMapper.writeValueAsString(getThing());
}
// The Jackson converter will do its ordinary serialization here.
#RequestMapping(path = "/endpoint")
public Thing getFlatThing() {
return new Thing();
}
the "flatMapper" implementation can be whatever you like so long as it works.
One option is to use Jackson's ObjectMapper to write the value as json first and then use https://github.com/wnameless/json-flattener to flatten that to your desired output. There may also be a way to define a custom ObjectMapper that does flat mapping, though that would take some more work on your part.
In my Spring web application, I have an API that accepts requests with application/x-www-form-urlencoded content type.
#RequestMapping(value = "/do-it", method = {RequestMethod.POST})
public String test(#ModelAttribute("request")RequestDTO request,HttpServletRequest
httpServletRequest, Map<String, Object> model, RedirectAttributes redirectAttributes){
.....
}
My RequestDTO has following fields in it.
public class RequestDTO {
private String paramOne;
private String paramTwo;
// standard getters and setters
}
This implementation works fine, all the request params get mapped to the request dto as expected. However, now I have this requirement to accept the requests with the fields in following pattern.
param_one, param_two
I understand that, using #JsonProperty annotation on the fields in my request dto is not gonna work in my case since the request is not in the type of application/json.
The only way I have found to solve the issue is creating new setters like following (which looks ugly in my opinion when it comes to naming convention).
public void setParam_one(String param_one) {
this.paramOne = param_one;
}
Can some one help me to find a better way to get this done? I cannot change the param names in original request dto.
Thank you..!
I was able to get this done. Thanks to #neetash for guiding me.
Everything I needed to have was a Custom HandlerMethodArgumentResolver to map the post request body data to the object that I wanted to get.
I followed following linked tutorial to implement it. It contains every single thing someone needs to know to create a HandlerMethodArgumentResolver.
https://www.petrikainulainen.net/programming/spring-framework/spring-from-the-trenches-creating-a-custom-handlermethodargumentresolver/
I have a DTO class and some REST services that sometimes return (among other things) a List of those DTOs.
I cannot alter that DTO, as it's used in several places of the project.
However, only for one specific REST service, I need to exclude some of the fields of that DTO object.
Basically I need to be able to apply this solution only at a certain point.
I tried applying #JsonFilter("restrictionFilter") to my DTO class, but then I get an error if I don't use that filter with a mapper every time I marshall the object into a JSON, like this:
final String writeValueAsString = mapper.writer(
new SimpleFilterProvider()
.addFilter("restrictionFilter",
SimpleBeanPropertyFilter.filterOutAllExcept("name", "sizeInByte"))
).writeValueAsString(objectsList);
The error is Cannot resolve PropertyFilter with id 'restrictionFilter'; no FilterProvider configured...
This issue sounds like a perfect Decorator design pattern use.
Create a new DTO with a constructor that gets the original DTO and create which get methods you want or ignore whatever get methods you like.
For example:
public class NewDto {
OldDto oldDto;
public NewDto(OldDto oldDto){
this.oldDto = oldDto;
}
public String getName(){
return oldDto.getName();
}
}
Now you will only need to return the NewDto object, like so:
return new NewDto(oldDto)
I'm going to implement a RESTful webservice using Spring.
Let it be an ordinary PUT method, something like this:
#RequestMapping(method=RequestMethod.PUT, value="/foo")
public #ResponseBody void updateFoo(#RequestBody Foo foo) {
fooService.update(foo);
}
In such a case input JSON format (if it corresponds to Foo class) will be successfully converted to Foo instance with no extra efforts, or error will be issued in case of wrong format.
But I'd like to make the service able to consume two different types of formats using same method (e.g. PUT) and same URL (e.g. /foo).
So that it possibly looked like:
//PUT method #1
#RequestMapping(method=RequestMethod.PUT, value="/foo")
public #ResponseBody void updateFoo(#RequestBody Foo foo) {
fooService.update(foo);
}
//PUT method #2
#RequestMapping(method=RequestMethod.PUT, value="/foo")
public #ResponseBody void updateFoo(#RequestBody FooExtra fooExtra) {
fooService.update(fooExtra);
}
and Spring converter tried to convert input JSON not only in Foo but in FooExtra as well and invoked corresponding PUT method depending on input format.
In fact, I tried to implement it exactly as it described above but without success. Is it even possible? Maybe, I need some kind of "trick"?
What is the best (and the most proper) way to achieve such behavior? Of course, I could always make two different URLs but I'd like to know whether it is possible with the same one.
Your attempt didn't work simply because Spring tried to match your methods against the request, by looking at url and method type, which are in both cases the same. It does not work like overloading in Java; argument types do not differentiate your methods.
But there are good news. SpringMVC can also examine request headers and request parameters when trying to match your handler methods. Since what you want to pass is actually pure metadata -an alternative format type of the same information- it makes perfect sense to use a custom request header. It's very easy to add custom headers when using a rest api. See the following link for JAX-RS: Adding a custom header.
Now in your server side you should configure the handler methods as:
//PUT method #1
#RequestMapping(method=RequestMethod.PUT, value="/foo", headers="returnType=Foo")
public #ResponseBody Foo updateFoo(#RequestBody Foo foo) {
fooService.update(foo);
}
//PUT method #2
#RequestMapping(method=RequestMethod.PUT, value="/foo", headers="returnType=FooExtra")
public #ResponseBody FooExtra updateFoo(#RequestBody FooExtra fooExtra) {
fooService.update(fooExtra);
}
Note also that if you want to access a return value with #ResponseBody you have to return your object, otherwise make the methods void
For understanding it we should think how Spring works, it uses Dispatcher Servlet. I don't think that spring does "combine" work for different types of input.
So my answer will be: "trick" with two different urls ;)