spring RequestHeader annotation on model object? - java

Can I put #RequestHeader on a model object property? I.e.
class MyModel {
String ua;
public void setUa(#RequestHeader("User-Agent") String ua) {
this.ua = ua;
}
}
This works with #RequestParam, but seems to have no effect when I use #RequestHeader. Am I missing something? And, if this isn't supported, is there some reason why?

You can do this only in controller methods. Not model objects. Check the documentation

Related

Make one property in request body not required

I have the following interface:
public interface TestRequestView {
String getCountryCode();
String getRegionCode();
}
It's used in several end points like so:
#PostMapping("/my/path/{id}")
public String test(#RequestBody TestRequestView request, #PathVariable String id) {
...
}
I would like to add a property to the TestRequestView that is only used in one new endpoint without breaking the rest, how can I mark that one property as ignorable? Something like:
public interface TestRequestView {
String getCountryCode();
String getRegionCode();
String getEmail(); // make this not required
}
Usually it is better to use 1 such a model per endpoint so they are independent. If you share models between endpoints this should be useful
This may help
You can use the #JsonIgnoreProperties annotation
Example:
#JsonIgnoreProperties(value = {"email"})
public interface TestRequestView {
String getCountryCode();
String getRegionCode();
#JsonProperty(required = false)
String getEmail();
}
Add annotation #JsonInclude(Include.NON_NULL) at class level for your TestRequestView. When passing your param you can pass it without that value and in your controller it will be received with that param as null. You just need to make sure that your controller can handle such case

Spring #RequestMapping deserializer

This is what I have:
SomeController.java
#Controller
#RequestMapping(value = "/foo", produces = MediaType.APPLICATION_JSON_VALUE)
public class SomeController {
#RequestMapping(value = "/bar", method = RequestMethod.POST)
public #ResponseBody ResponseEntity<Resource<Baz>> createCampaign(#RequestBody Foobar foobar) {
...
}
}
Now, I need to use a custom JsonDeserialiser for foobar, but only for this particular endpoint, every other endpoint with has Foobar as its #RequestBody should use the default. How can this be achieved?
I can't imagine an other way than doing things by hand. Get your request body as a plain string and call you custom JsonDeserializer with it :
public #ResponseBody ResponseEntity<Resource<Baz>> createCampaign(#RequestBody String body) {
//do your custom deserialization
}
How is different the deserialization of this instance in compare to the other ones?
Which version of of Jackson are you using? Jackson 2 enables pretty cool stuff for deserialization.
First option, you can use the Jackson Builder, to customize
#JsonDeserialize(builder = FooBarBuilder.class)
public class FooBar {
...
public static class FooBarBuilder() {
public FooBar build(){...}
}
}
Second option, if your actual FooBar is an subtype of a see Handling polymorphic types to resolve the actual instance of your class.
Hope it helps!

Do not serialize subtype properties with Jackson in Spring MVC 3

I am using Spring MVC with a controller like this:
#RequestMapping(value = "/list", method = RequestMethod.GET, produces = "application/json")
public #ResponseBody List<Service> list() {
return services.list();
}
The model is like this:
public class Service {
private User user;
...
}
public class User {
private String name;
...
}
public class ExtendedUser extends User {
private Location location;
...
}
For sure, an object of type ExtendedUser is created in the application and set in Service. When the controller /list answer the request, an object of type ExtendedUser is serialized despite the reference in Service class is User. I would like to know if there is some way with annotations to only serialize supertype (the referenced type) and avoid the subtype propierties.
Taking the example into account, I want a JSON without the location property to be returned.
Thanks in advance
Try #JsonInclude(Include.NON_NULL) on ExtendedUser
Your statement of "I want a JSON without the location property to be returned" can easily be accomplished using the #JsonIngore annotation:
public class ExtendedUser extends User {
#JsonIgnore
private Location location;
...
}
Is that what you're trying to do, though, just eliminate the location from the response, or does the actual type returned (type id) matter? If I'm off base, please post your expected JSON result and your actual JSON result.
I think this will do the trick:
#JsonSerialize(using=User.class)
See this related answer: https://stackoverflow.com/a/13926740/1292605
I recommend to use as property of #JsonSerialize. BTW, #JsonSerialize can be declared on the fields so that it will not impact the common behavior of serialization of User or ExtendedUser.
public class Service {
#JsonSerialize(as = User.class)
private User user;
...
}

Spring MVC, deserialize single JSON?

How can I easily separate JSON values that are sent in the same request?
Given that I POST a JSON to my server:
{"first":"A","second":"B"}
If I implement the following method in the Controller:
#RequestMapping(value = "/path", method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE)
public void handleRequest(#RequestBody String input) {
// ...
}
then the input parameter will constitute a String with the entire JSON object, {"first":"A","second":"B"}. What I really want is two separate Strings (or a String and an int whichever is suitable for the particular request) with just the two values (other key / value pairs that the client may send should be ignored).
If the strings were sent as request parameters instead of JSON request body it would be simple:
#RequestMapping(value = "/path", method = RequestMethod.POST)
public void handleRequest(#RequestParam("first") String first,
#RequestParam("second") String second) {
// ...
}
I know that I can create a simple bean class that can be used in conjunction with the #RequestBody annotation that will contain both A and B when used, but it seems like a detour, since they will have different purposes inside the web app.
Dependencies:
org.springframework : spring-web : 3.1.0.RELEASE
org.codehaus.jackson : jackson-mapper-asl : 1.9.3
POJO
public class Input {
private String first;
private String second;
//getters/setters
}
...and then:
public void handleRequest(#RequestBody Input input)
In this case you need Jackson to be available on the CLASSPATH.
Map
public void handleRequest(#RequestBody Map<String, String> input)
I have written a custom WebArgumentResolver that does exactly this, combined with a custom annotation.
I don't have the source available to me now, but basically I annotated my method like this:
#RequestMapping(value = "/path", method = RequestMethod.POST)
public void handleRequest(#JsonField("first") String first, #JsonField("second") String second) {
// ...
}
Then my JsonFieldWebArgumentResolver checks if the method parameter is annotated with JsonField, and if it is it extracts the actual type from the parameter (not quite straight-forward it turns out if you want to handle generic parameters as well, such as List<String> or List<Pojo>), and invokes Jackson's JsonParser manually to create the correct type. It's a shame I can't show you any code, but that's the gist of it.
However, that solution is for Spring MVC 3.0, and if you are using 3.1 I think you will be better off using a custom HandlerMethodArgumentResolver instead. But the idea should be the same.

How to create a default method in SpringMVC using annotations?

I can't find a solution to this, and it's driving me crazy. I have #Controller mapped that responds to several methods using #RequestMapping. I'd like to tag one of those methods as default when nothing more specific is specified. For example:
#Controller
#RequestMapping("/user/*")
public class UserController {
#RequestMapping("login")
public String login( MapModel model ) {}
#RequestMapping("logout")
public String logout( MapModel model ) {}
#RequestMapping("authenticate")
public String authenticate( MapModel model ) {}
}
So /user/login -> login method, /user/logout -> logout, etc. I'd like to make it so that if someone goes to /user then it routes to one of these methods. However, I don't see anything on #RequestMapping that would allow me to specify one of these methods as a default handler. I also don't see any other annotations that might be used on the class either to do this. I'm beginning to suspect it doesn't exist.
I'm using Spring 2.5.6. Is this solved in 3.0.0? I might just hack Spring to make it work because it's tremendously annoying this isn't more straightforward.
Thanks in Advance.
Take a look at this answer:
Spring MVC and annotated controllers issue
What if you annotate a method with:
#RequestMapping(method = RequestMethod.GET)
You can see an example here:
Spring 3.0 MVC + Hibernate : Simplified with Annotations – Tutorial
The same behavior can be seen here:
Spring Framework 3.0 MVC by Aaron Schram (look at page 21)
Short answer: I do not know how to simply specify one method as default with a simple tag.
But there is this ...
I do not know in which version of Spring this was implemented, but you can provide multiple values to #RequestMapping in 3.1.2. So I do this:
#Controller
#RequestMapping("/user")
public class UserController {
#RequestMapping(value = {"", "/", "/list"}, method = RequestMethod.GET)
public String listUsers(ModelMap model) { }
#RequestMapping(value = "/add", method = RequestMethod.POST)
public ModelAndView add(HttpServletRequest request, ModelMap model) { }
}
The following URLs then map to listUsers():
http://example.com/user
http://example.com/user/
http://example.com/user/list
I would create one default method without RequestMapping's value in there. Please see method defaultCall() below. You can then simply call them with URL: [yourhostname]/user
#Controller
#RequestMapping("/user")
public class UserController {
#RequestMapping(method = RequestMethod.GET)
public String defaultCall( MapModel model ) {
//Call the default method directly, or use the 'forward' String. Example:
return authenticate( model );
}
#RequestMapping("login")
public String login( MapModel model ) {}
#RequestMapping("logout")
public String logout( MapModel model ) {}
#RequestMapping("authenticate")
public String authenticate( MapModel model ) {}
}
Ref: Spring Framework Request Mapping
Simply using #RequestMapping("**") on your default method should work. Any more specific mappings should still pick up their requests. I use this method for setting up default methods sometimes. Currently using Spring v4.3.8.RELEASE.

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