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Use CriteriaBuilder to filter IN multiple ENUM values

I want to construct a query with CriteriaBuilder, and to add a Predicate into the where instruction, to filter one of my object field from a potential list of ENUM values.
Despite this similar post : Filtering data with CriteriaBuilder to compare enum values with literals not working
I didn't managed to make my code works. Here is the "simplified" object:
//BUNCH OF ANNOTATIONS
public class Action {
#Column(name = "CONTEXT")
#Enumerated(EnumType.STRING)
private ActionContext context = ActionContext.SALE;
// ...
}
My enum is:
public enum ActionContext {
SALE,
ORDER,
OTHER
}
And in my filters, I can for example receive something like "SALE,ORDER".
So I created a custom Specification, and when I construct it, I'm doing this :
private List<Predicate> filters = new ArrayList<>();
//...
// filterValue is a String, it can be "SALE,ORDER" for ex.
case CONTEXT_FILTER_NAME:
if (filterValue != null && !filterValue.isEmpty()) {
String[] contextTokens = filterValue.split(",");
CriteriaBuilder.In<String> inClause = cb.in(root.get(CONTEXT_FILTER_NAME));
Arrays.asList(contextTokens).forEach(inClause::value);
filters.add(inClause);
}
break;
The part after is just doing the query, it works for other filters ... but the fact my entity have an enum : when I run a test with these filters (sending "SALE,ORDER" filter for ex), I get the following error :
Parameter value [SALE] did not match expected type
[com.mycompany.domain.enums.ActionContext
I also tried by replacing CriteriaBuilder.in by .or() and putting in the collection of parsed tokens, but I had the same error.
And yes, I'm sure it's not a parsing error, because when I put a breakpoint in this swich/case section, I see the correctly constructed contextTokens array with good value in it. And in the Specification 'in' I can see the correct values being set.
Does anybody know what I'm missing ? thx a lot

OK I was comparing Enum with String, and I didn't see this ...
So you just have in this cases to convert ActionContext ENUM with ActionContext.valueOf(token) or on the other way around, converting the root.get(CONTEXT_FILTER_NAME).as(String.class).
Hope it helps people, that are like me, sometimes in a kind of tunnel vision.

How to pass list of parameters in rest get call (like filter object in eCommerce )

In my application, there is a requirement of getting data based on some parameters.
I just want to what is the better way to do.
The one way is, I can pass the list of parameters as a path variable.
The second way is, I can pass the request body, I think it is vague and I am not sure it is possible or not.
You can find the code below:
#GetMapping("/cities/{cityName}/latitude/{latitude}/longitude/{longitude}/cityId/{cityId}/street/{street}")
public ResponseEntity<ResponseContainer<CityDto>> getCityByCityNameOrLatitudeAndLongitude() {
}
I just want to know how can I achieve the same.
There is one more question, E-commerce companies have big filter criteria so how they are achieving.

Although there is no hard & fast rule but I generally avoid sending a body in GET request because it's a bad design. You should also refer to this SO Post which contains discussion about using body in GET request. It's an opinionated post and there is no clear YES or NO, but you will get an idea.
HTTP GET with request body
You can either use Path params or query params depending on what those field represent.
Regarding the difference or which to use when I am quoting this answer, which mentions that although there is no hard rule but generally it's better to use params which can uniquely identify the resource as Path param (e.g. id, name etc) and if your param is supposed to do something like filtering/sorting e.g. records after Jan 1 2019 , then go for query param.
Also personally in one of my APIs (which performs filtering), I am using a generic query param, where I pass on JSON object in my query. So basically my API needs to search an object based on variable/multiple attributes. E.g. I have in my db , objects which have certain voltage, current, size etc. values. So, request might come with a combination of 1 or more. So to keep my API flexible, I have provided a query param which can accept JSON object.
So I make a request like this:
{{SERVER}}/api/search?query={voltage:12V,size:10}
And in my API, I can convert this json object to corresponding POJO:
#GET
#Path("/search")
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public Response search(#QueryParam("query") String queryParam) throws Exception
{
Myobj obj = new Gson().fromJson(queryParam, Myobj.class);
// rest of code

By passing the parameters in the path, you are restricting yourself to extend your API. If you want to extend your API, for example, if you want to filter with criteria as Street1 (or) Street2 then your path wouldnot support it and it will force you to update your API. It is better to pass criteria objects in the body or url parameter. Amazon India is passing criteria like below. I have choosen mobiles with criteria as Manufacturer = Samsung or MI, Storage as 8gb or 4gb and they simply appended the criteria in the query parameters.

There is a third way, Request Params.
#GetMapping
public ResponseEntity<ResponseContainer<CityDto>> getCityByCityNameOrLatitudeAndLongitude(#RequestParam("cityName") String cityName, #RequestParam("latitude") String latitude, #RequestParam("longitude") String longitude){
// Your code
}
For more: 16.3.3.3 Binding request parameters to method parameters with #RequestParam
Parameters using this annotation are required by default, but you can specify that a parameter is optional by setting #RequestParam's required attribute to false (e.g., #RequestParam(value="id", required=false)).
https://docs.spring.io/spring/docs/3.1.x/spring-framework-reference/htmlsingle/spring-framework-reference.html#mvc-ann-requestparam

SpEL Cannot Be Cast to Map

Having read the documentation on "Inline Maps" for Spring Expression Language, I am passing an object to a SpelExpressionParser and .toString()ing the Object, so to speak; however, in doing so, I am receiving the following error:
org.springframework.expression.spel.standard.SpelExpression cannot be
cast to java.util.Map
The Object passed to as the argument to the .parseExpression function is the result of the annotation #PreAuthorize("hasPermission(#object, {name: 'roofus', animal: 'dog'}) "affixed" to a method.
Through the PermissionEvaluator interface implementation, it is passed in its Object form to a method:
private boolean doSomething (Object animal) { //....
Within this method is found an #Autowired SpelExpressionEvaluator. This is used in the following way:
Map animalMap = (Map) parser.parseExpression(animal.toString());
Through debugging, I know that the .toString() method results in: {name=roofus, animal=dog}
Resulting in the aforementioned error. Am I missing something? The goal is to be able to pass in a "JSON"-esque String (as specified by the linked documentation) for evaluation purposes.

Your problem that parser.parseExpression can't return Map independently of circumstances .
Looks like you misunderstood the architecture a bit. The SpelParser is for building Expression object from the the String. After that you can evaluate that expression using one of its getValue() method.
So, only after the evaluation you can get your Map object:
Expression expression = parser.parseExpression("{name: 'roofus', animal: 'dog'}");
Map map = expression.getValue(Map.class);

animal is already a Map (notice the formatting in the OP of the .toString() result) and not in the correct format expected by the parser. In this case, you don't even need the parser if the objective is to retrieve information from the Map:
((Map<String, String>)animal).get("animal")
So, in response to the solution proposed by Artem Bilan, this would actually work:
Map animalMap = (Map) parser.parseExpression("{name: 'roofus', animal: 'dog'}").getValue();
However, again, what is actually received (and the cause of the problem in the OP) is: parser.parseExpression("{name=roofus, animal=dog}")

Default/Constant values for POST/PUT arguments with Retrofit

Using the Retrofit REST Client library from Square, is there anyway of providing default/constant values for POST/PUT fields in a call.
I know about including constant query parameters by simply including them in the path, but this work for Body parameters.
I have an API that looks similar to:
POST /api/create
type=constanta&value={value}
POST /api/create
type=constantb&value={value}&otherValue={otherValue}
where the second variant requires an additional argument to be supplied. Rather than having a single java method that took all three arguments, I was hoping to be able to elide the constants from the method call, something like:
create(String value);
create(String value, String otherValue);
and have retrofit inject the type argument constant.
Given that adding #FormUrlEncoded can be added to modify how the body is encoded, if it's not natively supported by Retrofit, is there anyway of adding my own annotation and injecting such default values? ( It doesn't appear that RequestInterceptor allows one to modify the body.. ).

Maybe one option would be to send an object, which encapsulates all your values, instead of all string values separately? The object would implement your default values.
For example, you could create a class:
public class CreateObject {
private String type = "constant";
private String value;
private String otherValue;
public CreateObject(String value, String otherValue) {
this.value = value;
this.otherValue = otherValue;
}
}
Your class handles your constant. You could just set it to a default value "constant", like I did above, or set it on the fly in the constructor.
Now all you've to do is to create the object with the values and make the request with Retrofit. Instead of using the string values directly, just pass the object. Your interface could look like this:
public interface CreateService {
#POST("/api/create")
void create(#Body CreateObject create, Callback<CreateObject> cb);
}
The request implementation like this:
CreateObject create = new CreateObject("value", "otherValue");
createService.create(create, new Callback<CreateObject)() {…});
This should include all three of your values in the request body, if they are set. If a value is null, it won't be included in the request body. Based on your two examples above, you would now only need one interface method. Which values are sent is based on the createObject you pass on. For example, if you set otherValue as null, it won't be part of the request body.
My examples were modified from: https://futurestud.io/blog/retrofit-send-objects-in-request-body/

Is it possible for you to use Guava or Java 8 Optional as second argument in method? Then if that argument will be absent you can just ignore it

Spring, middle score in request parameter

Is there a way to map a query parameter with a middle score using requests in spring?
I have no problem binding single worded parameters doing this:
Uri example: http://localhost:8080/test/?product=hotels
public class CitiesRequest{
private ProductType product;
public ProductType getProduct() {
return this.product;
}
public void setProduct(String product) {
this.product = product;
}
}
But I'd like to be able to receive parameters like this:
http://localhost:8080/test/?product-type=hotels

As Misha stated it is syntactically incorrect to have a variable name with a hyphen in Java. But Spring is fine with that and allows you to specify a parameter name (in the request) different from the variable name (in java code). For exemple, when using RequestMapping driven controller, one can write :
#RequestMapping("/test")
public ModelAndView getProduct(
#RequestParam("product-type") String productType) {
...
}
That way, getProduct will be called for a url like http://localhost/test?product-type=hotels and the parameter productTypewill receive the value hotels. And all is still purely declarative.

By default, Spring maps the query parameter key to the name of the Java variable. However, it's syntactically incorrect to have a variable name with a hyphen in Java, which explains why you're finding it particularly difficult to get Spring to set the parameter's value for you.
One workaround that might work is to just have a Map<String, String[]> parameter to represent all of the parameters. Then Spring doesn't have to map any query parameters to variable names, so the hyphenated name might end up in that map of all parameters. It may not be as comfortable as pre-split parameter objects, but it might get the hyphenated keys.
Another solution might be to configure the WebDataBinder, which controls how data from HTTP requests are mapped onto your controller's request parameters. But that's a whole can of worms, especially if you're just starting out with Spring. You can read more about it in the documentation under "data binding".